Patent Publication Number: US-2023155141-A1

Title: Miniature Reserve Battery Arrays and Stand-Alone For Munitions and the Like

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of priority to U.S. Provisional Application No. 63/225,817, filed on Jul. 26, 2021, the entire contents of which is incorporated here by reference. 
    
    
     BACKGROUND 
     1. Field 
     The present disclosure relates generally to reserve power sources for munitions; and more particularly to liquid reserve batteries for use in gun-fired munitions, sub-munitions, mortars, rockets, missiles and the like that are easy to manufacture at relatively low cost, miniaturized, and sized to the available space. 
     2. Prior Art 
     Reserve batteries of the electrochemical type are well known in the art for a variety of uses where storage time before use is extremely long. Reserve batteries are in use in applications such as batteries for gun-fired munitions including guided and smart, mortars, fuzing mines, missiles, rockets, and many other military and commercial applications. The electrochemical reserve-type batteries can in general be divided into two different basic types. 
     The first type includes the so-called thermal batteries, which are to operate at high temperatures. Unlike liquid reserve batteries, in thermal batteries the electrolyte is already in the cells and therefore does not require a release and distribution mechanism such as spinning. The electrolyte is dry, solid and non-conductive, thereby leaving the battery in a non-operational and inert condition. These batteries incorporate pyrotechnic heat sources to melt the electrolyte just prior to use in order to make them electrically conductive and thereby making the battery active. The most common internal pyrotechnic is a blend of Fe and KClO 4 . Thermal batteries utilize a molten salt to serve as the electrolyte upon activation. The electrolytes are usually mixtures of alkali-halide salts and are used with the Li(Si)/FeS 2  or Li(Si)/CoS 2  battery couples. Some batteries also employ anodes of Li(Al) in place of the Li(Si) anodes. Insulation and internal heat sinks are used to maintain the electrolyte in its molten and conductive condition during the time of use. 
     The second type includes the so-called liquid reserve batteries in which the electrodes are fully assembled, but the liquid electrolyte is held in reserve in a separate container until the batteries are activated on demand. In these types of batteries, since there is no electrochemical reaction in the inactive (reserve) state, the shelf life of the batteries is essentially unlimited. The battery is activated by transferring the electrolyte from its container to the battery electrode compartment (hereinafter referred to as the “battery cell”). 
     A typical liquid reserve battery is kept inert during storage by keeping the aqueous electrolyte separate in a glass or metal ampoule or in a separate compartment inside the battery case. The electrolyte compartment may also be separated from the electrode compartment by a membrane or the like. Prior to use, the battery is activated by breaking the ampoule or puncturing the membrane allowing the electrolyte to flood the electrodes. The breaking of the ampoule or the puncturing of the membrane is achieved either mechanically using certain mechanisms or by the high-G firing setback shock. In these batteries, the projectile spin or a wicking action of the separator is generally used to transport the electrolyte into the battery cells. 
     In recent years, there have been a number of advancements in reserve battery technologies. Among these advances are superhydrophobic nanostructured materials, bimodal lithium reserve battery, and ceramic fiber separator for thermal batteries. In one liquid reserve battery technology under development, “superhydrophobic nanostructured material” is used in a honeycomb structure to keep the electrolyte separated from the battery cell. “Electrowetting” is achieved by the application of a trigger voltage pulse. The electrolyte can then penetrate the honeycomb structure and come into contact with the electrodes, thereby making the cell electrochemically active. 
     The thermal reserve batteries and liquid reserve batteries are initiated as a result of the munitions firing setback acceleration using inertial igniters such as those disclosed in U.S. Pat. Nos. 7,437,995; 7,587,979; 7,587,980; 7,832,335 and 8,061,271 and U.S. patent application Ser. Nos. 12/774,324; 12/794,763; 12/835,709; 13/180,469; 13/207,280 and 61/551,405 (the full disclosure of each of which being incorporated herein by reference) or piezoelectric-based inertial igniters such as those disclosed in U.S. Pat. No. 8,024,469 and U.S. patent application Ser. Nos. 13/186,456 and 13/207,355 the full disclosure of each of which being incorporated herein by reference) or other similar inertial or electrical initiators. The piezoelectric-based inertial igniters, particularly those that can provide relatively long initiation delay, are highly advantageous since by delaying the initiation, the time period in which the battery is subjected to high acceleration/deceleration levels is reduced or even eliminated. The reserve battery may also be activated following launch when its power is needed, which may in certain cases be long after launch and even landing. The initiation devices to be used must also be capable to operate safely by differentiating all-fire and various no-fire events such as accidental drops and vibration and impact during transportation and loading and even nearby explosions. The task of differentiating all-fire conditions from no-fire conditions can be performed without the use of external acceleration sensors and the like, and/or the use of external power sources. 
     The currently available liquid reserve batteries of all types and configurations and those that are known to be under development suffer from several basic shortcomings for munitions applications.
         1. The main shortcoming is their very poor performance at low temperatures, usually below −25 deg. F. and for becoming almost non-functional at lower temperatures. In most munition applications, however, the batteries are required to be operational at significantly below −40 deg. C. and sometimes as low as −54 deg. C.   2. The second shortcoming of liquid reserve batteries is their relatively slow rise time, particularly at low temperatures.   3. In addition, the use of glass ampule for electrolyte storage and its general has presented a wide range of manufacturing and safety problems. When bellow type electrolyte storage devices are used, such electrolyte storage devices only eject a relatively small fraction of their electrolyte content into the battery core and occupy a relatively large volume, thereby resulting in a significantly larger battery size.       

     In addition, in many applications, small reserve batteries, sometimes mm-scale or even smaller reserve batteries are needed for powering munitions electronics. Fabricating thermal batteries in sub-mm and even mm-scale is not practical due to thermal issues. The smallest liquid reserve battery fabricated to date is 0.25 inch in diameter. The only micro- and mm-scale battery concept developed to date uses hydrophobic membrane to store the battery electrolyte and release it by the application of an electric field. The concept, however, has the following basic shortcomings, particularly for munitions applications:
         1. The superhydrophobic membranes contain organic perfluorinated (e.g., PTFE) type coatings with poor shelf-life performance. Such membranes would not meet the military 20 years shelf-life requirement.   2. Battery activation requires onboard electrical power for electrowetting, which demands low current but relatively high voltages (electric field).   3. The use of high surface tension electrolytes can present difficulties in wetting the porous cathode electrodes, thereby resulting in relatively long activation times and loss of discharge capacity.   4. The batteries require gravity or spin to force the electrolyte to flow into the battery cell to activate the battery and stay in the battery core to activate and keep the battery in its activated state.       

     The small and mm-scale or even micro-scale reserve batteries have many munitions and commercial applications, particularly for emergency devices and systems. The small reserve batteries also present several advantages over larger reserve batteries, such as the fact that they can be distributed over the various components of the munition or the system in which they are used and be activated on demand. For example, such micro- and mm-scale reserve batteries may even be fabricated on a chip or can be mounted on circuit boards or the like and be directly integrated into electronic devices, sensors, and other power consuming components of munitions. Other beneficial characteristics of such small reserve batteries include the following:
         1. The micro-scale and mm-scale reserve batteries can be fabricated in arrays of individually activated cells by the host system controls to provide the desired voltage and power to intended components of the munition.   2. The reserve batteries can be configured to be hardened for a wide range of munitions applications. When fabricated in small sizes, such as in micro-scale or mm-scale, due to their small size, they can be configured to withstand very high firing setback and target impact accelerations and spin accelerations and rates.   3. The micro- and mm-scale reserve batteries may be fabricated on almost any substrate, including metallic substrates. The novel micro- and mm-scale reserve batteries may therefore be integrated into the structure of various components of the munition or other systems, thereby being distributed inside the munitions available space and close to the components being powered on demand.   4. Due to their small size, micro-scale and mm-scale reserve batteries can be configured to provide very rapid rise time unlike larger liquid reserve and thermal reserve batteries.   5. The micro-scale and mm-scale reserve batteries may be configured to be activated by setback acceleration upon munitions firing for initial powering of the munition system electronics. The need for other onboard sources of electrical energy is thereby eliminated.   6. The provision of setback acceleration activated micro-scale and mm-scale reserve batteries provides the means of powering munitions electronics very rapidly, potentially even before barrel exit.       

     The mm-scale reserve batteries can be readily scalable to significantly larger sizes, such as up to even several centimeters, and manufacturable without a significant amount of tooling and process modifications at lower costs. 
     The mm-scale reserve batteries can be capable being configured and fabricated in almost any cross-sectional geometries to occupy the available space in munitions or other devices and systems to minimize the spaces that are commonly occupied by reserve batteries. 
       FIG.  1    illustrates the cross-sectional view of a micro-scale and mm-scale reserve battery unit  10  of an array of such batteries of the prior art in its pre-activation and post activation states as disclosed in the U.S. Pat. Nos. 7,618,746 and 8,021,773. The battery array prototype is fabricated on a silicon wafer. In  FIG.  1   , a single battery unit of this liquid reserve battery type is shown with the housing  16  that is provided in the battery substrate  14 . The battery housing is sealed by a cap  15 . In this technology, “superhydrophobic nanostructured material” is used in a honeycomb structure as membrane  12 , to keep the electrolyte provided in the compartment  11  separated from the battery cell  17 . The membrane samples are produced in silicon in a honeycomb structure, and are then coated with the special hydrophobic coating, such as vapor deposited fluorocarbons to dip coatings of fluoropolymers (Teflon© and CYTOP©), to render them superhydrophobic. 
     “Electrowetting” is then achieved by the application of a trigger voltage pulse to the membrane. The electrolyte can then penetrate the honeycomb structure and come into contact with the electrodes  13 , thereby making the cell electrochemically active. In this activated state of the battery cell, the electrolyte is indicated by the numeral  18 . 
     The prior art liquid reserve battery configuration of  FIG.  1   , as was previously indicated, has many shortcomings. In addition, the flow of the electrolyte into the battery core is greatly inhibited due to the closed volume of the electrolyte compartment and the surface and the vacuum that is generated as the electrolyte would tend to flow into the battery core, particularly if the electrolyte as any significant surface tension, which is the case in higher performance electrolytes. In addition, the presence of the honeycomb membrane prevents the use of wicks to allow the electrolyte to be drawn into the battery core by capillary action. 
     SUMMARY 
     A need therefore exists for novel micro-scale and mm-scale liquid reserve batteries that can be manufactured in arrays of individually activated cells by the host system controls to provide the desired voltage and power to intended components on demand. 
     A need also exists for novel mm-scale reserve battery configurations that are readily scalable to significantly larger sizes, such as up to even several centimeters, and manufacturable without a significant amount of tooling and process modifications at lower costs. 
     A need also exists for novel mm-scale reserve batteries that are capable of being configured and fabricated in almost any cross-sectional geometries to occupy the available space in munitions or other devices and systems to minimize the spaces that are commonly occupied by reserve batteries. 
     A need also exists for novel micro-scale and mm-scale reserve battery configurations that can be hardened to withstand very high setback and target impact accelerations that may be as high as 100,000 Gs or more and high spin accelerations and spin rates that exceed 1000 Hz. 
     A need also exists for novel micro-scale and mm-scale reserve battery configurations that can be fabricated on almost any substrate, including metallic substrates. The novel micro- and mm-scale reserve batteries may therefore be integrated into the structure of various components of munitions or other devices and systems, thereby being capable of being distributed inside the available spaces in munitions or other systems and close to the components being powered on demand. 
     A need also exists for novel small size, micro-scale and mm-scale reserve batteries that can be configured to provide very rapid rise time, such as less than 10 milliseconds, unlike larger liquid reserve and thermal reserve batteries. 
     A need also exists for novel micro-scale and mm-scale reserve batteries that can be configured to be activated by setback acceleration upon munitions firing or upon target impact for initial powering of the munition system electronics. Such inertially activated reserve batteries would eliminate the need for other onboard sources of electrical energy. The initiation devices to be used must also be capable to operate safely by differentiating all-fire and various no-fire events such as accidental drops and vibration and impact during transportation and loading and even nearby explosions. The task of differentiating all-fire conditions from no-fire conditions can be performed without the use of external acceleration sensors and the like, and/or the use of external power sources. The inertial initiation mechanism can be integral to the structure of the reserve batteries. The novel micro-scale and mm-scale reserve batteries may also be activated following launch when its power is needed, which may in certain cases be long after launch and even landing. 
     A need also exits for novel micro-scale and mm-scale reserve batteries that can effectively operate with good performance at low temperatures, particularly at temperatures that may be as low as −54 deg. C. 
     An objective is to provide new liquid reserve batteries (power sources) that can be fabricated in micro-scale and/or mm-scale and be scaled to significantly larger, multi-centimeter scale. Such liquid reserve batteries can be used to power munitions, such as small and medium caliber munitions, sub-munitions, and the like. Such liquid reserve batteries can be used to power many commercial devices, such as emergency sensors, transmitters, alarm systems, and the like. 
     Another objective is to provide new types of liquid reserve batteries and methods of their configuration and construction such that they fabricated in micro-scale and mm-scale sizes as well as be readily scalable to significantly larger sizes, such as to even several centimeters, and manufacturable without a significant amount of tooling and process modifications at relatively low cost. 
     Another objective is to provide new types of liquid reserve batteries and methods of their configuration and construction such that they fabricated in arrays of micro-scale and mm-scale batteries that can be individually activated by the host controls on demand. 
     Another objective is to provide new types of liquid reserve batteries and methods of their configuration and construction with almost any cross-sectional geometries to occupy the available space in munitions or other devices and systems to minimize the spaces that are commonly occupied by reserve batteries. 
     Another objective is to provide new types of liquid reserve batteries and methods of their configuration and construction such that they can be hardened to withstand very high setback and target impact accelerations that may be as high as 100,000 Gs or more and high spin accelerations and spin rates that exceed 1000 Hz. 
     In particular, there is a need for relatively small reserve power sources for munitions, particularly for smaller caliber munitions, that can withstand very high firing accelerations; have very long shelf life, such as beyond 20 years; and that can be in munitions with very high spin acceleration and rates. 
     Another objective is to provide new types of liquid reserve batteries and methods of their configuration and construction for fabrication on various substrates, such as silicon, metallic and non-conductive substrates. The micro- and mm-scale and larger size (even several centimeter size) reserve batteries may therefore be integrated into the structure of various components of munitions or other devices and systems, thereby being capable of being distributed inside the available spaces in munitions or other systems and close to the components being powered on demand. 
     Another objective is to provide new types of liquid reserve batteries and methods of their configuration and construction so that they can provide very rapid rise time upon activation, such as even less than 10 milliseconds, unlike larger liquid reserve and thermal reserve batteries. 
     Another objective is to provide new types of liquid reserve batteries and methods of their configuration and construction that can be activated by setback acceleration upon munitions firing or upon target impact for initial powering of the munition system electronics to eliminate the need for other onboard sources of electrical energy. The initiation devices to be used must also be capable to operate safely by differentiating all-fire and various no-fire events such as accidental drops and vibration and impact during transportation and loading and even nearby explosions. The inertial initiation mechanism can be integral to the structure of the reserve batteries. 
     Another objective is to provide new types of liquid reserve batteries and methods of their configuration and construction such that they could be activated and operated with good performance at low temperatures, particularly at temperatures that may be as low as −54 deg. C. 
     In one disclosed micro-scale and/or mm-scale and/or significantly larger (centimeter scale) reserve batteries, the batteries can generally be classified as liquid reserve battery configuration type, in which the electrolyte is stored in a separate compartment and is separated from the battery core by a membrane. An electric current is then used to rupture the membrane and allow the electrolyte to be pulled into the battery core and activate the battery on demand. In this configuration, the battery is pulled into the battery core by the provided wick material via capillary action. As a result, unlike previously mentioned current micro-scale concept, the reserve battery does not rely on gravity or spin to eject the electrolyte into the battery core. 
     To ensure safety and reliability, the micro-scale and/or mm-scale and/or significantly larger (centimeter scale) reserve batteries are configured to withstand and not initiate during acceleration events which may occur during manufacture, assembly, handling, transport, accidental drops, etc. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       These and other features, aspects, and advantages of the apparatus of the present embodiments will become better understood with regard to the following description, appended claims, and accompanying drawings where: 
         FIG.  1    illustrates a sectional schematic of a micro-scale and mm-scale reserve battery unit of an array of such batteries of prior art in its pre-activation and post activation states. 
         FIG.  2    illustrates the schematic basic configuration of an array of micro-scale or mm-scale or larger scale batteries. 
         FIG.  3    illustrates the schematic of one of the micro-scale or mm-scale or larger scale battery units of the battery array of  FIG.  2   . 
         FIG.  4    illustrates the cross-sectional view of a single battery unit of  FIG.  3    of the first embodiment in its pre-activation (reserve) state. 
         FIG.  5    illustrates the cross-sectional view of a single battery unit of  FIG.  3    of the first embodiment in its activated state. 
         FIG.  6    illustrates the schematic of one solid membrane embodiment for separating the electrolyte storage compartment from the battery unit core compartment. 
         FIG.  7    illustrates the schematic of another solid membrane embodiment for separating the electrolyte storage compartment from the battery unit core compartment. 
         FIG.  8    illustrates the cross-sectional view of a single battery unit of  FIG.  3    of the second embodiment in its pre-activation (reserve) state and configured for inertial activation by firing setback acceleration. 
         FIG.  9    illustrates the cross-sectional view of a single battery unit of  FIG.  3    of the second embodiment in its post activation (reserve) state and configured for inertial activation by firing setback acceleration. 
         FIG.  10    illustrates the cross-sectional view of an alternative single battery unit of the embodiment of  FIG.  9    in its pre-activation (reserve) state as configured for inertial activation by firing setback acceleration. 
         FIG.  11    illustrates the cross-sectional view of the alternative single battery unit of the embodiment of  FIG.  9    in its activated state as configured for inertial activation by firing setback acceleration. 
         FIG.  12    illustrates the cross-sectional view of a single reserve battery unit of  FIG.  3    of the third embodiment in its pre-activation (reserve) state and configured for inertial activation by firing setback acceleration. 
         FIG.  13    illustrates the cross-sectional view of a single reserve battery unit of  FIG.  3    of the third embodiment in its post activation (reserve) state and configured for inertial activation by firing setback acceleration. 
         FIG.  14    illustrates the blow-up view “A” of the cross-sectional view of the reserve battery unit of embodiment of  FIG.  12   . 
         FIG.  15    illustrates the cross-sectional view of a stand-alone reserve battery unit embodiment in its pre-activation (reserve) state and configured for inertial activation by firing setback or impact acceleration. 
         FIG.  16    illustrates the cross-sectional view of the stand-alone reserve battery unit embodiment of  FIG.  15    in its post activation state. 
         FIG.  17    illustrates the cross-sectional view of another stand-alone reserve battery unit embodiment in its pre-activation (reserve) state and configured for inertial activation by firing setback or impact acceleration. 
         FIG.  18    illustrates the cross-sectional view of the stand-alone reserve battery unit embodiment of  FIG.  17    in its post activation state. 
         FIG.  19    illustrates the cross-sectional view of the first manually activated stand-alone reserve battery unit embodiment in its pre-activation (reserve) state. 
         FIG.  20    illustrates the cross-sectional view of the manually activated stand-alone reserve battery embodiment of  FIG.  19    in its post activation state. 
         FIG.  21    illustrates the cross-sectional view of the modified version of the manually activated stand-alone reserve battery embodiment of  FIG.  19    configured for inertial activation in its pre-activation (reserve) state. 
         FIG.  22    illustrates the cross-sectional view of the modified stand-alone reserve battery embodiment of  FIG.  21    in its post activation state. 
         FIG.  23    illustrates the cross-sectional view of another stand-alone reserve battery embodiment in its pre-activation (reserve) state and configured for inertial activation by firing setback or impact acceleration. 
         FIG.  24    illustrates the cross-sectional view of the stand-alone reserve battery unit embodiment of  FIG.  23    in its post activation state. 
         FIG.  25    illustrates the cross-sectional view of a modified version of the stand-alone reserve battery embodiment of  FIG.  23    in its pre-activation (reserve) state and configured with added charge collector pressure spring member. 
     
    
    
     DETAILED DESCRIPTION 
     A configuration of an array of micro-scale or mm-scale and even larger scale batteries is shown in the schematic of  FIG.  2    and indicated by the numeral  20  and is hereinafter referred to as the “battery array”. The array of battery units is generally fabricated in a substrate, which may be a silicon wafer or almost any other material that may have to be provided with an appropriate coating to serve as the housing for the battery unit. The battery array may also be covered by a thin and relatively flexible and extensible layer (such as silicon rubber) to provide for sealing from an outside environment as to assist in battery activation as described later in this disclosure. 
     The “battery array”  20  of  FIG.  2    may contain any number of “battery units”  21 , which may be equal sizes or different sizes and with different cross-sectional geometry as viewed in planes parallel to its top surface (e.g., with square, rectangular, circular, or oval cross-sections). The battery units  21  can have constant cross-sections along their height, i.e., in the depth of their cavities inside the substrate  19 . The battery units may also be distributed over the structures of various devices to provide a distributed power system to provide power on demand and avoid wiring over relatively long distances. 
     In the schematic of  FIG.  2   , the terminals  22  of the battery units  21  are shown to exit from the side of the array substrate  19 , but it may also be configured to exit from any desired direction, including from the bottom surface of the substrate  19 , for example, having surface electrodes for direct mounting to a printer circuit board. 
       FIG.  3    illustrates the schematic of one of the micro-scale or mm-scale or larger scale battery units  21  of the battery array of  FIG.  2    and is indicated by the numeral  25 . The battery unit  25  is housed in a corresponding cavity provided in the battery array  20 ,  FIG.  2   . In the schematic of  FIG.  3   , the side walls  23  and the bottom side of the cavity are then part of the substrate  19  of the battery array  20 ,  FIG.  2   . The battery top cover  26  (not shown in  FIG.  2    for the sake of clarity) is then provided to seal the battery unit compartments. A battery unit  25  may also be provided with lead wires  27  for battery activation as described later in this disclosure. The battery array can be fabricated on almost any component structure as well as on-the-chip to accommodate the battery units as later described. 
     The cross-sectional view of a single battery unit of  FIG.  3    of the first embodiment is shown in the schematic of  FIG.  4    and is indicated by the numeral  30 . In the schematic of  FIG.  4   , the side walls  28  and the bottom side  29  of the battery unit cavity are part of the substrate  19  of the battery array  20 ,  FIG.  2   . As can be seen in  FIG.  4   , the inside volume of the battery unit embodiment  30  is divided into a lower compartment  33  and an upper compartment  36  by a relatively solid separator membrane  34 . The lower compartment  33  constitutes the battery core, within which the cathode  31  and anode  32  components of the battery and their separator  38  are positioned. The void in the cavity  33  can be filled with a wick material to pull the electrolyte into the battery compartment  33  by capillary action upon battery activation as described later. 
     In the schematic of  FIG.  4   , the battery terminals  37  (their surrounding electrical insulation layer not shown) are shown to exit from the bottom surface  29  of the battery unit. The compartment  36  of the battery unit embodiment  30  is used to store the battery electrolyte while the battery unit is in its pre-activation (reserve) state. The battery top cover  35  ( 26  in  FIG.  3   ) can be a relatively thin flexible and extensible (for example, silicon rubber or the like) layer. 
     Battery unit embodiment  30  is then activated by partial removal/rupture of the membrane  34  barrier and allowing the electrolyte from the compartment  36  to flow into the battery core compartment  33  as later described. In  FIG.  5    the battery unit embodiment  30  is shown in its activated state. 
     As can be seen in  FIG.  4   , prior to the battery activation, the electrolyte is stored between the membrane  34  and the battery top thin flexible and extensible (silicon rubber or the like) layer  35 . Then following partial rupture of the membrane  34  as is described later and indicated with the openings  39  in  FIG.  5   , the liquid electrolyte is released and is pulled into the battery core by the capillary action of the provided wick material in the compartment  33 ,  FIG.  4   , filling the battery core around the cathode  31  and anode  32 , respectively, as shown in  FIG.  5   . Hereinafter, the rupture, breaking, piercing, melting or any another means for changing the membrane from a sealed state in which the electrolyte is sealed in the compartment having the electrolyte ( 36  in  FIG.  4   ) to an unsealed state in which the electrolyte can flow into the compartment having the anode and cathode ( 33  in  FIG.  5   ) is collectively referred to as the membrane being “broken.” 
     As the liquid electrolyte is pulled into the battery core cavity by the indicated capillary action of the provided wick material, the top flexible and extensible layer  42  ( 35  in  FIG.  4   ) would expand to fill the vacated volume as shown in  FIG.  5   , allowing most of the electrolyte to be moved into the battery core, leaving a negligible amount of electrolyte (indicated by the numeral  41  in  FIG.  5   ) in the spaces left between the conforming flexible and extensible layer  42  and the remnants of the membrane  34  and the walls  28  ( FIG.  4   ) seen in  FIG.  5   . 
     It is appreciated by those skilled in the art that the provision of the wick material in the battery core compartment  33  and the indicated use of capillary action to pull the liquid electrolyte into the battery core to activate the battery eliminates the need for gravity or other pressurization method to force the electrolyte into the battery core as is the case for the prior art embodiment of  FIG.  1   . In addition, the provision of the thin flexible and extensible layer ( 35  in  FIG.  4    and in its deformed state  42  in  FIG.  5   ) overcomes the generated vacuum in the electrolyte storage compartment as is the case in the prior art embodiment of  FIG.  1   . 
     The battery units  30  shown in the cross-sectional view of  FIG.  4    may be configured and fabricated and operate with several types of membranes  34 , including the ones described below. All provided membrane options are configured to overcome the previously indicated shortcomings of hydrophobic membranes of different types used in the battery units of prior art of  FIG.  1   . 
     In one embodiment, a solid separator membrane  43 ,  FIG.  6   , made of a low melting temperature material, such as a paraffinic wax or similar material, is used to separate the electrolyte compartment  36  from the battery unit active components compartment  33  in the pre-activation (reserve) state as shown in the cross-sectional view  FIG.  4   . The solid separator membrane  43  is provided with an embedded heating element  44  (heating filament) as shown in  FIG.  6   , which is powered via the terminals  45  ( 27  in  FIG.  3   ), to partially melt the wax to allow the stored electrolyte to flow into the battery unit compartment  33 . The porous wick material would also assist in drawing the electrolyte into the battery core by the capillary action. In practice, the low melting temperature material (e.g., paraffinic wax or other similar material) may be directly deposited over the indicated wick material. 
     It is appreciated that the embedded heating element  44  is configured to act like bridge wires used in electrical initiators and could also be coated with some minute particles (not shown) of pyrotechnic material to facilitate and expedite partial melting process of the paraffinic wax or similar material layer  43 . 
     Alternatively, to facilitate deposition of the filament wire using semiconductor foundry processes or the like, the heating filament  46  may be deposited over a solid layer  47 , for example a thin ceramic layer with a series of openings  49  which are then covered by the sealing layer of solid paraffin wax or the like  48  as shown in  FIG.  7   . The filament wire  46  may be similarly coated with some minute particles of pyrotechnic material to facilitate and expedite partial melting process of the wax layer. The terminals  51  ( 27  in  FIG.  3   ) are used to power the filament wire  46 . 
     The cross-sectional view of a single battery unit of  FIG.  3    of the second embodiment is shown in the schematic of  FIG.  8    and is indicated by the numeral  50 . The battery unit  50  is shown in its pre-activation state in  FIG.  8   . In the schematic of  FIG.  8   , the side walls  52  and the bottom side  53  of the battery unit cavity are part of the substrate  19  of the battery array  20 ,  FIG.  2   . As can be seen in  FIG.  8   , the inside volume of the battery unit embodiment  50  is divided into a lower compartment  54  and an upper compartment  55  by a relatively solid separator membrane  56 . The lower compartment  54  constitutes the battery core, within which the cathode  57  and anode  58  components of the battery and their separator  59  are positioned. The void in the cavity  54  can be filled with a wick material to pull the electrolyte filling the upper compartment  55  into the battery compartment  54  by capillary action upon battery activation as described later. In the schematic of  FIG.  8    the battery terminals  62  (their surrounding electrical insulation layer not shown) are shown to exit from the bottom surface  53  of the battery unit. 
     The battery units  50  cavities, like the embodiment  30  of  FIG.  4   , may still be configured in an array form on the array substrates as shown in the schematics of  FIG.  2   . The substrate may be a silicon wafer or almost any other material that may have to be provided with an appropriate coating to serve as the housing of a battery unit. 
     As indicated, the solid separator membrane  56 , which may be a thin ceramic or the like material membrane, is used to separate the electrolyte filling the compartment  55  from the battery active compartment  54  as shown in the cross-sectional view of the battery unit  50  in its pre-activation (reserve) state in  FIG.  8   . 
     As can be seen in  FIG.  8   , the battery unit  50  is provided with an inertial mass  61 , which is provided with peripheral seal  63  to seal the electrolyte within the compartment  55 . The inertial mass  61  is otherwise free to be forced to translate downward as seen in the view of  FIG.  8   . 
     As can be seen in  FIG.  8   , the battery electrolyte fills the volume provided between the solid membrane  56  and the sealed inertial mass  61 . In practice, the seal is deposited over the entire periphery of the inertial mass. The inertial mass  61  is also provided with one or more membrane cutter (puncturing) members  64 , depending on the size of the reserve battery unit  50 . 
     Now when the reserve battery unit  50  is subjected to firing setback acceleration in the direction of the arrow  60  as seen in  FIG.  8   , the inertial force acting on the inertial mass  61  is configured to apply a downward force on the inertial mass  61  and begin to displace it downward, causing the “membrane cutters”  64  to puncture the membrane  56  (punctured opening shown schematically openings indicated by numeral  66  in  FIG.  9   ) and force the electrolyte to flow into the battery core, thereby activating the battery unit  50  as shown in the battery unit activated state of  FIG.  9   . In the activated state of the battery unit shown in  FIG.  9   , the inertial mass is indicated by the numeral  67  ( 61  in pre-activated state of  FIG.  8   ) and its “membrane cutters” by the numeral  68 . It is appreciated that the cathode  57  and anode  58  are shaped to allow the membrane cutters  68  to clear the two components while breaking through the membrane  56 ,  FIG.  8   . 
     An alternative configuration of the inertially activated reserve battery unit  50  of  FIG.  8   , which would facilitate its mass manufacture is shown in its pre-activated and activated states in  FIGS.  10  and  11    and indicated as embodiment  70 . The reserve battery unit embodiment  70  is identical to the battery unit embodiment  50  of  FIG.  8   , except for the added flexible and extensible top sealing layer  71  (usually a deposited silicon rubber or the like layer), which is used to seal the battery interior from outside environment, and that the peripheral seal  63  is no longer necessary, but may in practice be provided for the purpose of stability during the process of manufacturing the battery units and vibration and accidental drop resistance. The reserve battery units  70  are, however, provided with a flexible and extensible top sealing layer  71  (such as deposited silicon rubber or the like), which in addition of being capable of being “stretched” to conform to the geometry described below, is also intended to provide for the sealing action before and after battery activation to protect the battery unit interior from environmental elements. 
     Now when the reserve battery unit  70  is subjected to firing setback acceleration in the direction of the arrow  72  as seen in  FIG.  10   , the inertial force acting on the inertial mass  61  is configured to apply a downward force on the inertial mass  61  and begin to displace it downward, causing the “membrane cutters”  64  ( 74  in  FIG.  11   ) to puncture the membrane  56  (punctured opening shown schematically openings indicated by numeral  73  in  FIG.  11   ) and force the electrolyte to flow into the battery core compartment  54 , thereby activating the reserve battery unit  70  as shown in the battery unit activated state of  FIG.  11   . In the battery unit  70  activated state of  FIG.  11   , the inertial mass is indicated by the numeral  75  and its “membrane cutters” by the numeral  76 . It is appreciated that the cathode  57  and anode  58  are shaped to allow the membrane cutters  74  to clear the two components while breaking through the membrane  56 ,  FIG.  10   . 
     It is appreciated that as the liquid electrolyte is pushed into the battery core cavity  54  by the inertial mass  75  downward displacement, the top flexible and extensible layer  71 ,  FIG.  10   , would expand to fill most of the vacated volume as shown in  FIG.  11    and indicated by the numeral  77 . 
     The cross-sectional view of a single battery unit of  FIG.  3    of the third embodiment is shown in the schematic of  FIG.  12    and is indicated by the numeral  80 . The battery unit  80  is shown in its pre-activation state in  FIG.  12   . In the schematic of  FIG.  12   , the side walls  81  and the bottom side  82  of the battery unit cavity are part of the substrate  19  of the battery array  20 ,  FIG.  2   . As can be seen in  FIG.  12   , the inside volume of the battery unit embodiment  80  is divided into a lower compartment  83  and an upper compartment  84  by a relatively solid separator membrane  85 . The lower compartment  83  comprises the battery core, within which the cathode  86  and anode  87  components of the battery and their separator  89  are positioned. The void in the cavity  83  may be filled with a wick material to pull the electrolyte filling the upper compartment  84  into the battery compartment  83  by capillary action upon battery activation as described later. In the schematic of  FIG.  12    the battery terminals (their surrounding electrical insulation layer not shown)  88  are shown to exit from the bottom surface  82  of the battery unit. 
     The battery units  80  cavities, like the embodiment  30  of  FIG.  4   , may still be configured in an array form on the array substrates as shown in the schematics of  FIG.  2   . The substrate may be a silicon wafer or almost any other material that may have to be provided with an appropriate coating to serve as the housing of a battery unit. 
     As indicated, the solid separator membrane  85 , which may be a thin ceramic or the like material membrane, is used to separate the electrolyte filling the compartment  84  from the battery active compartment  83  as shown in the cross-sectional view of the battery unit  80  in its pre-activation (reserve) state in  FIG.  12   . 
     As can be seen in  FIG.  12   , the battery unit  80  is provided with an inertial mass  90 , which is provided with peripheral seal  91  to seal the electrolyte within the compartment  84 . The inertial mass  80  is provided with several (such as three or four) cylindrical holes  92 , which are symmetrically positioned around the inertial mass  80  as shown in  FIG.  12   . In each cylindrical hole, a preloaded compressive spring  93  is provided, which is used to press the ball  95  into the provided dimple  94  formed on an inside the side wall  81  as shown in  FIG.  12   . The spring rate of the compressive springs  93  and their preloading level are selected such that the inertial mass  90  would be prevented to displace down enough to release the balls  95  from the dimples  94 , unless the battery unit  80  is subjected to a high enough acceleration level and for long enough duration in the direction of the arrow  96  (corresponding to the munitions no-fire condition using the battery unit). Once the inertial mass  90  has displaced down enough to free the balls  95  out of the dimples  94 , the inertial mass is then free to be forced to translate downward as seen in the view of  FIG.  12   , with minimal frictional resistance from the balls  95  and the seal  91 . 
     As can be seen in  FIG.  12   , the battery electrolyte fills the volume provided between the solid membrane  85  and the sealed inertial mass  90 . In practice, the seal is deposited over the entire periphery of the inertial mass. The inertial mass  90  is also provided with one or more membrane cutter (puncturing) members  97 , depending on the size of the reserve battery unit  80 . 
     Now when the reserve battery unit  80  is subjected to firing setback acceleration in the direction of the arrow  96  as seen in  FIG.  12   , the inertial force acting on the inertial mass  90  is configured to apply a downward force on the inertial mass  90 , which if it is larger than the retaining force provided by the balls  94  in the dimples  95  due to the preloading force of the compressive springs  93 , then the inertial mass  90  would begin displace downward. Now, if the acceleration in the direction of the arrow  96  ceases before the balls  94  have fully disengaged the dimples  95 , then the preloaded compressive springs would force the balls  94  back into the dimples  95 , thereby returning the inertial mass  90  to its pre-acceleration state shown in  FIG.  12   . This could, for example, happen due to accidental drop of the device in which the reserve battery unit  80  is positioned or due to transportation vibration or other accidental events due to which the reserve battery unit  80  is not to activate (no-fire conditions in munitions). However, if the acceleration in the direction of the arrow  96  has high enough magnitude and long enough duration (which is considered to be an “all-fire condition” in munitions), then the inertial mass  90  continues to displace downward, causing the “membrane cutters”  99  ( 97  in  FIG.  12   ) to puncture the membrane  98  ( 85  in  FIG.  12   ). In  FIG.  13   , the punctured openings are shown schematically and indicated by numeral  100 . The electrolyte stored in the compartment  84  ( FIG.  12   ) is then forced to flow into the battery core compartment  83 , thereby activating the reserve battery unit  80  as shown in the reserve battery unit activated state of  FIG.  13   . In the activated state of the reserve battery unit  80  shown in  FIG.  13   , the inertial mass  90  is indicated by the numeral  101  and its “membrane cutters” by the numeral  99 . It is appreciated that the cathode  86  and anode  87  are shaped to allow the membrane cutters  99  to clear the two components while breaking through the membrane  85 ,  FIG.  12   . 
       FIG.  14    shows the blow-up view “A” of the cross-sectional view of the reserve battery unit of embodiment of  FIG.  12   . The blow-up view “A” shows one method of securing the solid membrane  85  to the reserve battery unit side wall  81  and sealing the battery electrolyte in the battery unit compartment  84 ,  FIG.  12   . As can be seen in  FIG.  14   , the solid membrane  85  sits against the “sleeve”  102 , which fits inside the battery core compartment  83 ,  FIG.  2   . Alternatively, the “sleeve”  102  may be formed as a step integral to the side wall  81 . The rigid membrane  85  is then sealed against the interior surface  104  of the side wall  81  by a relatively small bead  103  of a sealant, for example, silicon rubber or the like depending on the type of sealant being used. 
     In addition, all relatively thin solid membranes are required to be electrically non-conductive. A thin solid membrane may be relatively brittle so that they would readily fracture by the relatively sharp “membrane cutters” (e.g.,  97  in  FIG.  12   ), which may be assisted by the provision of stress concentrating grooves or the like on the battery core side of the membranes. Alternatively, a solid membrane may be configured of a readily ruptured material such as a woven and sealed (e.g., with a paraffinic wax layer) fiberglass fabric that is readily punctured by the relatively sharp “membrane cutters” (e.g.,  97  in  FIG.  12   ). In the latter case, the “membrane cutters” can be provided with a side “channels” (e.g., may have a “C” shape profile) to assist in the flow of the electrolyte into the battery core. 
     It is appreciated that like the reserve battery unit embodiment  70  of  FIG.  10   , the reserve battery unit embodiment  80  of  FIG.  12    may also be provided with the added flexible and extensible top sealing layer  105  ( 71  in  FIG.  10   ), which is used to seal the battery interior from outside environment. The sealing layer  105  is usually a deposited silicon rubber or the like layer. 
     It is also appreciated that as the liquid electrolyte is pushed into the battery core cavity  83  by the inertial mass  90  downward displacement, the top flexible and extensible layer  105 ,  FIG.  12   , would expand to fill most of the vacated volume as shown in  FIG.  13    and indicated by the numeral  106 . 
     In the schematic of the reserve battery unit  25  of  FIG.  3   , the battery unit is shown to have a square or rectangular cross-section (in the direction parallel to the top cover  26 ). It is, however, appreciated by those skilled in the art that the reserve battery units may have almost any cross-sectional geometry, particularly circular, which may make their manufacture easier. It is also appreciated that the battery units shown in the schematic of  FIG.  2    do not have to be all the same size, shape and the same type described in the disclosed embodiments. The battery units may also be distributed over its substrate in any appropriate regular or irregular pattern, for example, they may be arranged around various component of the device in which they are used to maximize space and volume efficiency, particularly in munitions. 
     It is appreciated by those skilled in the art that the reserve battery unit  25  of  FIG.  3    may also be configured and fabricated as a stand-alone reserve battery as compared to its array configuration described for the previous embodiments. It is also appreciated that such stand-alone reserve batteries may have almost any cross-sectional geometries, even non-uniform cross-sections along their height (indicated from the bottom surface, for example, surface  29  in  FIG.  4   ). However, for stand-alone reserve batteries, uniform circular cross-sectional geometries are easier to manufacture and is used in describing such batteries in this disclosure without limiting the embodiment to such a geometry. 
     The cross-sectional view of the first stand-alone reserve battery embodiment  110  is shown in the schematic of  FIG.  15   . The stand-alone reserve battery  110  may have a circular cross-section or any other appropriate cross-section that may be required to accommodate the available space in the device in which it is used to minimize the total occupied space. In the schematic of  FIG.  15   , the battery housing  107  can be in one piece as shown but may also be constructed by a cylinder side to which the bottom cap  108  is attached, such as by welding or the like. As can be seen in  FIG.  15   , the inside volume of the reserve battery  110  is divided into a lower compartment  109  and an upper compartment  111  by a relatively solid separator membrane  119 . The lower compartment  109  comprises the battery core, within which the cathode  112  and anode  113  components of the battery and their separator  114  are positioned. The void  115  in the cavity  109  can be filled with a wick material to pull the electrolyte into the battery compartment  109  by capillary action upon battery activation as described later. 
     In the schematic of  FIG.  15    the battery terminals  116  (their surrounding electrical insulation layer not shown) are shown to exit from the bottom surface  108  of the battery unit. However, the battery may be configured with terminal exits on the side or top cap of the battery. One of the terminals may also be configured to be the housing body  107  or the top cap surface  117 . 
     The compartment  111  of the stand-alone battery embodiment  110  is used to store the battery electrolyte while the battery is in its pre-activation (reserve) state shown in  FIG.  15   . The battery top cover  117  is fixedly attached to the battery housing  107 , such as by welding or other similar means, particularly when the battery is required to be hermetically sealed. The top cover  117  is part of the member  118 , which is used to house the inertial activation mechanism of the battery described later. 
     The stand-alone reserve battery embodiment  110  is then activated by partial removal/rupture of the solid membrane  119  barrier and allowing the electrolyte from the compartment  111  to flow into the battery core compartment  109  as later described. In  FIG.  16   , the reserve battery embodiment  110  is shown in its activated state. 
     As can be seen in  FIG.  15   , prior to the battery activation, the electrolyte is stored between the membrane  119  and the battery top cap  117 . Then following partial rupture of the membrane  119  as is described later and indicated with the openings  120  in  FIG.  16   , the liquid electrolyte is released and is pulled into the battery core by the capillary action of the provided wick material in the that compartment  109 ,  FIG.  15   , filling the battery core free space  115  around the cathode  112  and anode  113 , respectively, as shown in  FIG.  16   . 
     It is appreciated by those skilled in the art that the provision of the wick material in the battery core compartment open space  115  and the indicated use of capillary action to pull the liquid electrolyte into the battery core to activate the battery eliminates the need for gravity or other pressurization method to force the electrolyte into the battery core as is the case for the prior art embodiment of  FIG.  1   . 
     As it was previously indicated, the top cover  117  of the stand-alone reserve battery embodiment  110  of  FIG.  15    is part of the member  118 , which is used to house the inertial activation mechanism of the battery described later. It is appreciated by those skilled in the art that many different types of activation mechanisms may be used for this purpose. However, for safety purposes, those types that have the capability of differentiating the prescribed activation acceleration profile, i.e., the minimum acceleration level and duration (all-fire condition in munitions), from all other accidental accelerations (no-fire conditions in munitions) can be used. The activation mechanism shown in the stand-alone reserve battery embodiment  110  of  FIG.  15    is such an activation mechanism. 
     It is also appreciated by those skilled in the art that the type of solid membranes  34  used in the embodiment  30  of  FIG.  4   , such as those shown in the schematics of  FIGS.  6  and  7    may also be used similarly for activation of the disclosed stand-along reserve batteries, such as the stand-alone reserve battery of  FIG.  15   . 
     As can be seen in  FIG.  15   , the battery unit  110  is provided with an inertial activation mechanism, which is mounted inside the member  118 . The activation mechanism comprises a release lever  121 , which is fixedly attached to the inside surface of the member  118  by a rotary joint  122 . The release lever is held in the position shown in  FIG.  15    by a preloaded tensile spring  123 . The membrane rupturing member of the activation mechanism is the lever  124 , which is also fixedly attached to the inside surface of the member  118  by a rotary joint  125 . In the pre-activation (reserve) state of the battery embodiment  110  shown in the schematic of  FIG.  15   , the tip  127  of the lever  124  rests against tip  126  of the release lever  121 . In general, the membrane rupturing link  124  is provided with a stop in the joint  125  or a stop  128  to prevent/minimize its clockwise rotation as viewed in  FIG.  15    while in its pre-activation state. 
     Now when the stand-alone reserve battery embodiment  110  is subjected to firing setback acceleration or the like in the direction of the arrow  129  as seen in  FIG.  15   , the acceleration acts on the centers of mass of the levers  121  and  124 , thereby applying a dynamic torsional load to the lever  121  that tends to rotate it in the clockwise direction as viewed in  FIG.  15   . The preloaded tensile spring  123  would however, tend to counter the applied dynamic torsional load. The spring rate of the preloaded tensile spring  123  and its preloading level are selected such that the applied dynamic torsional load would be prevented from rotating the lever  121  in the clockwise direction enough to disengage and release the lever  124  unless the acceleration in the direction of the arrow  129  has the prescribed minimum magnitude and duration (all-fire condition in munitions) as described below. If the applied acceleration in the direction of the arrow  129  is below the prescribed magnitude and duration (all no-fire conditions in munitions), then even if the lever  121  has rotated slightly (i.e., before disengaging and releasing the lever  124 ), it would return to its initial position shown in the pre-activation (reserve) state of  FIG.  15   . The location of the centers of mass of the levers  121  and  124  and their distances from the joints  122  and  125 , respectively, and their magnitudes and the spring rate and preloading level of the tensile spring  123  are the parameters that are used to configure the present battery activation mechanisms to achieve the prescribed acceleration profile, i.e., minimum acceleration magnitude and its duration. 
     Now if the stand-alone reserve battery embodiment  110  of  FIG.  15    is subjected to an acceleration in the direction of the arrow  129  that is above the minimum prescribed acceleration and duration (all-fire condition in munitions), then the lever  121  is rotated in the clockwise direction until the tip  127  of the membrane rupturing link  124  disengages the tip  126  of the release lever, thereby freeing the membrane rupturing link  124  to continue to rotate in the counterclockwise direction and rupture the membrane  119  as shown in the post activation state schematic of the battery in  FIG.  16   . In  FIG.  16   , the punctured opening in the membrane  119  is shown schematically and indicated by numeral  120 . The liquid electrolyte stored in the compartment  111  is then released and is pulled into the battery core by the capillary action of the provided wick material in the compartment  109 ,  FIG.  15   , filling the battery core free space  115  around the cathode  112  and anode  113 , as shown in  FIG.  16   , thereby activating the stand-alone reserve battery embodiment  110 . It is appreciated that the cathode  112  and anode  113  and the separator  114  are shaped to allow the membrane rupturing link  124  to clear the three components while rupturing (or breaking when more brittle membrane material is used) the membrane  119 . 
     In the stand-alone reserve battery embodiment  110  of  FIG.  15   , the release lever  121  of the activation mechanism is attached to the member  118  by a rotary joint  122 . It is, however, appreciated by those skilled in the art that the release lever may be a relatively flexible member (beam) that is attached to the member  118  by a living joint and is to provide bending resistance for the release of the membrane rupturing link  124  for the battery activation as was described above. 
     The cross-sectional view of the second stand-alone reserve battery embodiment  130  is shown in the schematic of  FIG.  17   . The stand-alone reserve battery  130  may have a circular cross-section or any other appropriate cross-section that may be required to accommodate the available space in the device in which it is used to minimize the total occupied space. All components of the stand-alone reserve battery embodiment  130  of  FIG.  17    is identical to that of the stand-alone reserve battery embodiment  110  of  FIG.  15    and are identically indicated numerally, except for the top cover member  131  ( 117  in  FIG.  15   ) and its contained inertial activation mechanism. 
     The compartment  111  of the stand-alone battery embodiment  130  is similarly used to store the battery electrolyte while the battery is in its pre-activation (reserve) state shown in  FIG.  17   . The battery top cover  131  is fixedly attached to the battery housing  107 , such as by welding or other similar means, particularly when the battery is required to be hermetically sealed. The top cover  117  is part of the member  132  ( 118  in  FIG.  15   ), which is used to house the inertial activation mechanism of the battery described later. 
     The stand-alone reserve battery embodiment  130  is then activated by partial removal/rupture of the solid membrane  119  barrier and allowing the electrolyte from the compartment  111  to flow into the battery core compartment  109  as later described. In  FIG.  18   , the stand-alone reserve battery embodiment  130  is shown in its activated state. 
     As can be seen in  FIG.  17   , prior to the battery activation, the electrolyte is stored between the membrane  119  and the battery top cap  117 . Then following partial rupture of the membrane  119  as is described later and indicated with the openings  142  in  FIG.  18   , the liquid electrolyte is released and is pulled into the battery core by the capillary action of the provided wick material in the that compartment  109 ,  FIG.  17   , filling the battery core free space  115  around the cathode  112  and anode  113 , respectively, as shown in  FIG.  18   . 
     It is appreciated by those skilled in the art that the provision of the wick material in the battery core compartment open space  115  and the indicated use of capillary action to pull the liquid electrolyte into the battery core to activate the battery eliminates the need for gravity or other pressurization method to force the electrolyte into the battery core as is the case for the prior art embodiment of  FIG.  1   . 
     It is appreciated that the above methods of supporting the relatively thin solid membrane  85  of the reserve battery unit embodiment  80  and sealing it to prevent the electrolyte from flowing into the battery core compartment  83  as shown in the blow-up view of  FIG.  14    may also be used for the previously described battery unit embodiments, i.e., the embodiments  30 ,  50  and  70  of  FIGS.  4 ,  8  and  10   , respectively, and all stand-alone reserve batteries, such as the embodiments  110  and  130  of  FIGS.  15  and  17   , respectively. 
     As it was previously indicated, the top cover  131  of the stand-alone reserve battery embodiment  130  of  FIG.  17    is part of the member  132  ( 118  in  FIG.  15   ), which is used to house the inertial activation mechanism of the battery described later. It is appreciated by those skilled in the art that many different types of activation mechanisms may be used for this purpose. However, for safety purposes, those types that have the capability of differentiating the prescribed activation acceleration profile, i.e., the minimum acceleration level and duration (all-fire condition in munitions), from all other accidental accelerations (no-fire conditions in munitions) can be used. The activation mechanism shown in the stand-alone reserve battery embodiment  130  of  FIG.  17    is such an activation mechanism. 
     It is also appreciated by those skilled in the art that the type of solid membranes  34  used in the embodiment  30  of  FIG.  4   , such as those shown in the schematics of  FIGS.  6  and  7    may also be used similarly for activation of the disclosed stand-along reserve embodiment  130  of  FIG.  17   . 
     As can be seen in  FIG.  17   , the stand-alone reserve battery embodiment  130  is provided with an inertial activation mechanism, which is mounted inside the member  131 . The activation mechanism comprises a lever  133 , which is fixedly attached to the bottom surface of the member  131  by a rotary joint  134  via the support member  135 . The lever  133  is held in the position shown in  FIG.  17    by a preloaded tensile spring  136 , which is attached on one end  137  to the inner wall of the member  131  and on the other end to the lever  138  as shown in  FIG.  17   . As can be seen in the pre-activation state of the stand-alone reserve battery embodiment  130  in  FIG.  17   , the line of action of the preloaded tensile spring  136  is above the rotary joint  134  of the lever  133 , thereby biasing it to stay in the configuration shown in  FIG.  17    against the bottom surface of the top member  131  or another provided stop (not provided in the schematic of  FIG.  17   ). 
     It is appreciated by those skilled in the art that the inertial activation mechanism of the stand-alone reserve battery embodiment  130  of  FIG.  17    is a toggle mechanism, which in the schematic of  FIG.  17    is shown in one of its stable configurations. 
     The membrane rupturing member of the activation mechanism is the lever  133 . In the pre-activation (reserve) state of the battery embodiment  130  shown in the schematic of  FIG.  17   , the cutting (breaking or shattering) member  139  of the lever  133  is at its farthest distance from the solid membrane  119  as shown in the schematic of  FIG.  17   . 
     Now when the stand-alone reserve battery embodiment  130  is subjected to firing setback or impact acceleration or the like in the direction of the arrow  141  as seen in  FIG.  17   , the acceleration acts on the center of mass of the lever  133 , thereby applying a dynamic torsional load to the lever  133  that tends to rotate it in the clockwise direction as viewed in  FIG.  17   . The preloaded tensile spring  136  would however, tend to counter the applied dynamic torsional load. The spring rate of the preloaded tensile spring  136  and its preloading level are selected such that the applied dynamic torsional load would be prevented from rotating the lever  133  in the clockwise direction passed the point at which the line of action of the tensile spring  136  force passes through the axis of rotation of the rotary joint  134 , that is at the unstable configuration of the toggle mechanism formed by the lever  133  and the preloaded tensile spring  136 , unless the acceleration in the direction of the arrow  141  has the prescribed minimum magnitude and duration (all-fire condition in munitions) as described below. 
     If the applied acceleration in the direction of the arrow  141  is below the prescribed magnitude and duration (all no-fire conditions in munitions), then even if the lever  133  has rotated slightly (i.e., reaching its unstable configuration), it would return to its initial position shown in the pre-activation (reserve) state configuration of  FIG.  17   . The location of the center of mass of the lever  133  and its distance from the joint  134 , the mass of the lever  133 , the spring rate and preloading level of the tensile spring  136  are the parameters that are used to configuration the present toggle mechanism type battery activation mechanism to achieve the prescribed acceleration profile, i.e., minimum acceleration magnitude and its duration. 
     Now if the stand-alone reserve battery embodiment  130  of  FIG.  17    is subjected to an acceleration in the direction of the arrow  141  that is above the minimum prescribed acceleration level and duration (all-fire condition in munitions), then the lever  133  is rotated in the clockwise direction until the toggle mechanism reaches and passes its aforementioned unstable configuration, from which position, the lever  133  is rotationally accelerated further in the clockwise direction under the aforementioned applied dynamic torsional load as well as the torque generated by the preloaded tensile spring  136 . The cutting (breaking or shattering) member  139  of lever  133  would then rupture the membrane  119  ( 143  in  FIG.  18   ) as shown in the post activation state schematic of the battery in  FIG.  18   . 
     In  FIG.  18   , the punctured opening in the membrane  143  ( 119  in  FIG.  17   ) is shown schematically and indicated by numeral  142 . The liquid electrolyte stored in the compartment  111  is then released and is pulled into the battery core by the capillary action of the provided wick material in the compartment  109 ,  FIG.  17   , filling the battery core free space  115  around the cathode  112  and anode  113 , as shown in  FIG.  18   , thereby activating the stand-alone reserve battery embodiment  130 . It is appreciated that the cathode  112  and anode  113  and the separator  114  are shaped to allow the cutting (breaking or shattering) member  139  of lever  133  rupture the membrane  119  ( 143  in  FIG.  18   ) while clearing these three components. 
     In the stand-alone reserve battery embodiment  130  of  FIG.  17   , the lever  133  of the activation mechanism is attached to the member  132  by a rotary joint  134 . It is, however, appreciated by those skilled in the art that the lever  133  may alternatively be attached to the member  132  by a living joint to simplify the construction of the activation mechanism and its assembly, particularly for relatively small reserve batteries. 
     The cross-sectional view of the first manually activated stand-alone reserve battery embodiment  140  is shown in the schematic of  FIG.  19   . The stand-alone reserve battery  140  may have a circular cross-section or any other appropriate cross-section that may be required to accommodate the available space in the device in which it is used to minimize the total occupied space. In the schematic of  FIG.  19   , the battery housing  144  can be in one piece as shown but may also be constructed by a cylinder side to which the bottom cap  145  is attached, such as by welding or the like. As can be seen in  FIG.  19   , the inside volume of the manually activated stand-alone reserve battery  140  is divided into a lower compartment  146  and an upper compartment  147  by a relatively solid separator membrane  148 . The lower compartment  146  constitutes the battery core, within which the cathode  149  and anode  150  components of the battery and their separator  151  are positioned. The void  115  in the cavity  146  can be filled with a wick material (not shown) to pull the electrolyte into the battery compartment  146  by capillary action upon battery activation as described later. 
     In the schematic of  FIG.  19    the battery terminals  153  (their surrounding electrical insulation layer not shown) are shown to exit from the bottom surface  145  of the battery unit. However, the battery may be configured with terminal exits on the side or top cap of the battery. One of the terminals may also be configured to be the housing body  144 . 
     The compartment  147  of the stand-alone battery embodiment  140  is used to store the battery electrolyte while the battery is in its pre-activation (reserve) state shown in  FIG.  19   . The battery top cover  154 , which can be made with the same material as the battery housing  144  and is fabricated as a diaphragm to make it flexible in the axial direction (up and down as seen in the view of  FIG.  19   ), is fixedly attached to the battery housing  144 , such as by welding or other similar means, particularly when the battery is required to be hermetically sealed. Such metal diaphragms are well known in the art and are used widely in pressure sensors, diaphragm pumps, and the like. 
     The stand-alone reserve battery embodiment  140  is then activated by partial removal/rupture of the solid membrane  148  barrier and allowing the electrolyte in the space  155  from the compartment  147  to flow into the battery core compartment  146  as later described. In  FIG.  120   , the reserve battery embodiment  140  is shown in its activated state. 
     As can be seen in  FIG.  19   , prior to the battery activation, the electrolyte in the space  155  is stored between the membrane  148  and the battery top cap  154 . Then following partial rupture of the membrane  148  as is described later and indicated with the openings  159  in  FIG.  20   , the liquid electrolyte is released and is pulled into the battery core by the capillary action of the provided wick material in the that compartment  146 ,  FIG.  19   , filling the battery core free space  152  around the cathode  149  and anode  150  as shown in  FIG.  20   . 
     It is appreciated by those skilled in the art that the provision of the wick material in the battery core compartment open space  152  and the indicated use of capillary action to pull the liquid electrolyte into the battery core to activate the battery eliminates the need for gravity or other pressurization method to force the electrolyte into the battery core as is the case for the prior art embodiment of  FIG.  1   . 
     As can be seen in the schematic of  FIG.  19   , the battery top diaphragm cap  154  is provided with cutting (breaking or shattering) members  156 , which are fixedly attached to the battery side surface of the cap  154 . In the pre-activation (reserve) state of the battery embodiment  140  shown in the schematic of  FIG.  19   , the membrane  148  cutting members  156  are positioned slightly above the surface of the membrane  148 . 
     The stand-alone reserve battery embodiment  140  of  FIG.  19    is configured to be manually activated. Now if the battery top diaphragm cap  154  ( 158  in  FIG.  20   ) is pressed down manually (or by certain electrical or pneumatic or the like actuator known in the art) in the direction of the arrow  157 , then the central region of the battery top diaphragm cap  154  would displace in the direction of the arrow  157 , causing the diaphragm cap  154  to deform to the configuration  158  shown in  FIG.  20   , thereby causing the cutting (breaking or shattering) members  156  to create an opening  159  in the membrane  161  ( 148  in  FIG.  19   ). The liquid electrolyte stored in the space  155  of the compartment  147  is then released and is pulled into the battery core by the capillary action of the provided wick material in the compartment  146 ,  FIG.  20   , filling the battery core free space  152  around the cathode  149  and anode  150 , as shown in  FIG.  20   , thereby activating the stand-alone reserve battery embodiment  140 . It is appreciated that the cathode  149  and anode  150  and the separator  151  are shaped to allow the membrane cutting member  156  clear the three components while rupturing (or breaking when more brittle membrane material is used) the membrane  148  ( 161  in  FIG.  20   ). 
     The stand-alone reserve battery embodiment  140  of  FIG.  19    was shown to be configured to be activated manually (or by the use of an electrical, pneumatic or the like linear actuator or the like known in the art). It is, however, appreciated by those skilled in the art that this reserve battery configuration can be readily modified to become capable of being activated inertially when subjected to a prescribed acceleration, for example firing setback or impact acceleration in munitions. This modified version of the stand-alone reserve battery embodiment  140  of  FIG.  19    is shown schematically in  FIG.  21    and is indicated as the stand-alone reserve battery embodiment  160 . 
     The cross-sectional view of the modified stand-alone reserve battery embodiment  140  of  FIG.  19    is shown in the schematic of  FIG.  21    and indicated as the embodiment  160 . All components of the modified stand-alone reserve battery embodiment  160  are identical to that of the embodiment  140  of  FIG.  19    except for the addition of the mass member  162 , which is fixedly attached to the battery diaphragm top cap  154 , such as by welding or brazing or the like, as shown in  FIG.  21   . In the schematic of  FIG.  21   , the modified stand-alone reserve battery embodiment  160  is shown in its pre-activation state. 
     In the modified stand-alone reserve battery embodiment  160 , the effective inertia of the provided mass member  162  and the battery diaphragm top cap  154  would determine the dynamic force that acts downward on the battery diaphragm top cap  154 , as viewed in  FIG.  21   , as the battery is accelerated in the direction of the arrow  163 . In addition, the effective spring rate of the battery diaphragm top cap  154  in response to a force applied in the direction of the arrow  157 ,  FIG.  20   , determines the amount of downward displacement of the mass member  162 , noting that said spring rate of the diaphragm top cap  154  is not linear and would generally increase with increased deflection. 
     The mass of the mass member  162  and the spring rate of the battery diaphragm top cap  154  are selected such that the mass member  162  is prevented from displacing down enough for the cutting members  156  to rupture (break or shatter) the membrane  148 ,  FIG.  21   , unless the stand-alone reserve battery  160  is subjected to a high enough acceleration level and for long enough duration in the direction of the arrow  163  (e.g., corresponding to the munition all-fire condition using the reserve battery). Once the mass member  162  and thereby the cutting members  156  have displaced down enough for the cutting member to create the opening  159  in the membrane  148  (membrane with the opening  159  is indicated by the numeral  161  in  FIG.  22   ), the electrolyte stored in the compartment  147  of the battery is free to flow into the battery core compartment  146 . 
     Now when the reserve modified stand-alone reserve battery embodiment  160  is subjected to the previously described firing setback or impact acceleration profile, i.e., minimum acceleration level and duration, in the direction of the arrow  163 ,  FIG.  21   , the inertial force acting on the effective inertial of the mass member  162  and the top cap diaphragm  154  is configured to displace the cutting members  156  downwards enough to engage and cut (break or shatter) the membrane  148  and create the opening  159  in the membrane ( 161  with the opening  159  in  FIG.  22   ). Otherwise, if the acceleration in the direction of the arrow  163  ceases before the cutting member  156  would engage the membrane  148 ,  FIG.  21   , then the top cap diaphragm  154  would return the mass member to its pre-activation state. This could, for example, happen due to accidental drop of the device in which the reserve battery unit  160  is positioned or due to transportation vibration or other accidental events due to which the reserve battery  160  is not to activate (no-fire conditions in munitions). 
     Now, when the modified stand-alone reserve battery embodiment  160  is subjected to the aforementioned prescribed high enough magnitude and long enough duration (e.g., all-fire condition in munitions), then once the opening  159  is created in the membrane  161 ,  FIG.  22   , the electrolyte stored in the space  155  of the compartment  147  would flow into the battery core compartment  146 , thereby activating the reserve battery as shown in  FIG.  22   . The electrolyte flow into the battery core compartment  146  is assisted by the wick material filling usually provided in the space around the cathode, anode, and the separator by capillary action. 
     The cross-sectional view of another stand-alone reserve battery embodiment  170  is shown in the schematic of  FIG.  23   . The stand-alone reserve battery  170  may have a circular cross-section or any other appropriate cross-section that may be required to accommodate the available space in the device in which it is used to minimize the total occupied space. In the schematic of  FIG.  23   , the battery housing  164  such as in one piece as shown but may also be constructed by a cylinder side to which the bottom cap  165  is attached, such as by welding or the like. The battery anode  166  is positioned against the inner surface of the bottom cap  165 , thereby making the battery housing  164 , including its bottom cap  165  as the negative terminal of the battery. The cathode  168  is positioned over the anode  166  and separated from it by the separator  169 . Both anode  166  and cathode  168  are separated from the inside wall surface of the housing  164  by the electrical insulating layer  167 , for example one made from Teflon. 
     A metal (for example made from copper) charge collector  171  is positioned firmly against the cathode  168  inside the insulating layer  167  to prevent it from contact with the surface of the housing  164 . The charge collector  171  is provided with series of openings  172  to allow the battery electrolyte stored in the compartment  173  to flow into cathode  168  side of the battery core upon battery activation. 
     The charge collector  171  is held firmly against the cathode  168  by the electrically non-conductive member  174 , which is provided with a step section  175 , which is used to hold the charge collector  171  firmly against the cathode  168  as well as to accommodate the relatively rigid membrane  176 , which is, for example, made of a relatively thin ceramic material such as alumina, so that it can be readily broken (shattered) as described later to activate the battery. The relatively rigid membrane  176  is sealed against the side of the non-conductive member  174 , for example by a “bead”  177  of silicon rubber or the like as shown in  FIG.  23   . 
     The void space  179  between the membrane  176  and the charge collector  168  can be filled with a wick material (not shown) to pull the electrolyte into the void space by capillary action upon battery activation as described later. 
     The battery housing  164  is capped by the cap member  180 , such as by welding or the like, particularly when the battery must be hermetically sealed. The cap member  180  may be formed at its periphery by a lip  181  or the housing wall may be provided with a step (not shown) or the like to facilitate the welding of the cap member  180  to the battery housing  164 . The cap member  180  is also provided with an opening  182  through which the positive terminal  183  of the battery exits. The opening  182  in the cap member  180  is filled and sealed by an electrically non-conductive material, such as glass, through which the terminal wire  183  is shown to pass. The terminal wire  183  extends through the electrically non-conductive member  174 , and is attached to the charge collector  171 , such as by soldering or the like with good electrical conductivity. The terminal wire  183  is connected to the charge collector  168  by the conductive wire  189 , such as by soldering. 
     The compartment  173  within which the battery electrolyte is stored in the pre-activation state of the stand-alone reserve battery embodiment  170  is formed between the relatively rigid membrane  176  and the cap member  180  with the sides of the electrically non-conductive member  174 . The previously described sealing  177  and sealing provided between the cap member  180  and the electrically non-conductive member  174  (not shown for the sake of clarity) ensures that the liquid electrolyte stays within the compartment  173 . 
     The stand-alone reserve battery embodiment  170  is provided with an inertial activation mechanism. The inertial activation mechanism in this battery is shown to comprise a relatively flexible beam element  184 , which is fixedly attached to the inner surface of the cap member  180 , such as by welding or brazing or the like. The beam element  184  is flexible with a selected stiffness in the bending direction of its free end to which a relatively sharp cutting (breaking or shattering) member  178  is fixedly attached. In the pre-activation state of the battery, the flexible beam  184  is preloaded to be biased against the inner surface of the cap member  180  to provide the capability of achieving prescribed battery activation when a prescribed acceleration in the direction of the arrow  186  is detected as described later. 
     The stand-alone reserve battery embodiment  170  is then activated by partial removal/rupture of the solid membrane  176  barrier and allowing the electrolyte from the compartment  173  to flow into the void space  179 , assisted with the capillary action of the filling wick material, and through the space  179  to diffuse into the cathode  168  through the openings  172  provided in the charge collector  171 , thereby activating the battery. In  FIG.  24   , the reserve battery embodiment  170  is shown in its activated state. 
     It is appreciated by those skilled in the art that the provision of the wick material in the void space  179  and the indicated use of capillary action to pull the liquid electrolyte into space  179  to activate the battery eliminates the need for gravity or other pressurization method to force the electrolyte into the battery core as is the case for the prior art embodiment of  FIG.  1   . It is appreciated by those skilled in the art that many different types of activation mechanisms may be used in place of the mechanism comprising the flexible beam  184  and the cutting member  178 . However, for safety purposes, those types that have the capability of differentiating the prescribed activation acceleration profile, i.e., the minimum acceleration level and duration (all-fire condition in munitions), from all other accidental accelerations (no-fire conditions in munitions) can be used. The activation mechanism shown in the stand-alone reserve battery embodiment  170  of  FIG.  23    is such an activation mechanism. 
     It is also appreciated by those skilled in the art that the type of solid membranes  34  used in the embodiment  30  of  FIG.  4   , such as those shown in the schematics of  FIGS.  6  and  7    may also be used similarly for activation of the disclosed stand-along reserve batteries, such as the stand-alone reserve battery embodiment  170  of  FIG.  23   . 
     Now when the stand-alone reserve battery embodiment  170  is subjected to firing setback acceleration or the like in the direction of the arrow  186  as seen in  FIG.  23   , the acceleration acts on the centers of mass of the flexible beam  184  and cutting member  178  assembly, thereby applying a dynamic bending moment to the flexible beam  184  that tends to displace the cutting member downward as viewed in  FIG.  23   . The preloaded flexible beam  184  would however, tend to counter the applied dynamic bending moment. The bending flexibility of the preloaded flexible beam  184  and its preloading level are selected such that the applied dynamic bending moment would be prevented from deflecting the cutting member  178  enough to engage and rupture (break or shatter) the membrane  176  unless the acceleration in the direction of the arrow  186  has the prescribed minimum magnitude and duration (all-fire condition in munitions). If the applied acceleration in the direction of the arrow  186  is below the prescribed magnitude and duration (all no-fire conditions in munitions), then the dynamic bending moment would either not be large enough to overcome the beam preload and/or enough time to displace the cutting member  178  down enough to engage the membrane  176 . As a result, the flexible beam  184  and cutting member  178  assembly would return to its initial position shown in the pre-activation (reserve) state of  FIG.  23   . The location of the effective center of mass of the flexible beam  184  and cutting member  178  assembly and its distance from the fixed end  185  and its magnitude and the flexural bending rate and preloading level of the flexible beam  184  are the parameters that are used to configuration the present battery activation mechanisms to achieve the prescribed acceleration profile, i.e., minimum acceleration magnitude and its duration. 
     Now if the stand-alone reserve battery embodiment  170  of  FIG.  23    is subjected to an acceleration in the direction of the arrow  186  that is above the minimum prescribed acceleration and duration (all-fire condition in munitions), then the cutting member  178  is displaced down as viewed in  FIG.  23    and would engage and rupture (break or shatter) the electrically non-conductive membrane  176  as shown in the post activation state schematic of the battery in  FIG.  24   . In  FIG.  24   , the punctured opening in the membrane  176  is shown schematically and indicated by numeral  187 . The liquid electrolyte stored in the compartment  173  is then released and is pulled into the space  179  by mostly the capillary action of the provided wick material, filling the space  179  and diffusing into the cathode  168  through the openings  172  in the charge collector  171 , thereby activating the stand-alone reserve battery embodiment  170 . 
     A stop limiting downward displacement of the cutting member  178  (not shown for the sake of clarity) can be provided to ensure that the cutting member  178  does not come into contact with the charge collector  168 . 
     It is appreciated by those skilled in the art that in stand-alone reserve batteries such as the embodiment  170  of  FIG.  23   , the charge collector  168  can be pressed against the cathode  168  for efficient operation of the battery upon activation. This can, for example, be achieved by modifying the embodiment  170  and providing preloaded compressive springs between the electrically non-conductive member  174  and the charge collector as shown in the cross-sectional schematic of  FIG.  25    and indicated by the numeral  190 . 
     The stand-alone reserve battery embodiment  190  of  FIG.  25    has all its components identical to that of the embodiment  170  of  FIG.  23   , except for the components modifications to allow for the provision of preloaded spring used to pressure the charge collector  171  against the cathode  168  as described below. 
     As can be seen in the schematic of  FIG.  25   , the step section  191  ( 175  in  FIG.  23   ) of the electrically non-conductive member  192  ( 174  in  FIG.  23   ) is extended to cover a larger surface area of the charge collector  168 . The opening  194  in the step section  191  is then covered by the relatively rigid membrane  193  ( 176  in  FIG.  23   ), which is held and sealed to the section  191  by seal  195  to prevent the electrolyte to flow from the compartment  173  into the space  179  between the section  191  and the charge collector  171 . A compressively preloaded wave spring  196  is then positioned between the section  191  and the charge collector  171  to apply a constant pressure to the charge collector and thereby keep the charge collector  171  pressed against the cathode  168 . 
     Then when the stand-alone reserve battery embodiment  190  of  FIG.  25    is subjected to acceleration in the direction of the arrow  197  and the acceleration has the prescribed minimum magnitude and duration, then the cutting member  178  displace down as viewed in  FIG.  25    due to the bending deflection of the flexible beam  184  as was previously described for the embodiment  170  of  FIG.  23   , and ruptures (breaks or shatter) the membrane  193 , allowing the electrolyte to flow through the created opening  194  into the space  179 , such as assisted by the capillary action of the wick material in the space  179 . The electrolyte will then diffuse into the cathode  168  and activate the battery as was described for the embodiment  170  of  FIG.  23   . 
     It is appreciated by those skilled in the art that the no stored mechanical energy is provided to the above stand-alone inertially activated reserve battery embodiments, i.e., embodiment of  FIGS.  8 ,  10 ,  12 ,  15 ,  17 ,  21 ,  23  and  24   . In many applications, including in many munition applications, particularly when the firing setback or impact induced activation acceleration is relatively high and has relatively long duration (at least in the order of 4-10 milliseconds), such stand-alone inertially activated reserve battery embodiments can be used. However, when the firing setback or impact induced activation acceleration level is low (usually below 200-300 G) and/or its duration is short (in the order of 1-4 milliseconds), then stored mechanical energy in the form of preloaded tensile or compressive springs, which are then released by the firing setback or impact induced activation acceleration, can be used to achieve battery activation. 
     While there has been shown and described what is considered to be preferred embodiments of the invention, it will, of course, be understood that various modifications and changes in form or detail could readily be made without departing from the spirit of the invention. It is therefore intended that the invention be not limited to the exact forms described and illustrated but should be constructed to cover all modifications that may fall within the scope of the appended claims.