Abstract:
An improved battery case for armored vehicles the case having an inlet and outlet, the case halving means that opens the case for airflow when the interior temperature of the case reaches a predetermined value. The case is further insulated so it will minimize the transfer of heat from the surrounding engine components and armor plate.

Description:
GOVERNMENT INTEREST 
     The invention described here may be made, used and licensed by and for the U. S. Government for governmental purposes without paying us any royalty. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     In one aspect this invention relates to storage cases for batteries. In a further aspect this invention relates to a battery casing for extending armored vehicle battery life. 
     2. Prior Art 
     In general ground vehicles have one or more storage batteries as a means to store electrical energy for starting the vehicle and operating auxiliary equipment when the vehicle&#39;s prime mover is turned off. Armored combat type vehicles present unusual and extreme problems for storage batteries. Such vehicles must maintain hull or outer structure integrity in order to provide protection against various projectiles. Thus, the use of openings in the hull structure must be minimized both in number and size. Also the structure of combat vehicles results in a closed exterior that admits to little or no airflow by convection through the hull or engine compartment. In addition, military vehicles are exposed to weather extremes that severely stress the components while failure can create casualties. 
     In armored vehicles exposed to desert conditions the sun will heat the vehicle&#39;s armor to temperatures in the 150 to 180 F. range which in turn will raise the battery temperature to a similar range even when not operating. When operating and the batteries are working or being charged, the battery&#39;s temperatures will climb still higher. The result is water evaporates from the battery fluid and diminishes the battery capacity and efficiency. During the most severe high temperature ambient conditions it becomes necessary to add distilled water to the battery on a daily basis since the battery temperature will approach the boiling point of water with a resulting very high rate of evaporation. Because the batteries are under the armor shell they are difficult to service and the possibility of failure is raised. In addition to high ambient temperatures, combat vehicles are exposed to large quantities of air borne dust. Any battery ventilation system should account for the dusty conditions and have means for particle removal, preferably in a passive mode. 
     The location of the batteries creates yet a further problem. Because the batteries are located under the armor shell, the preference is to site them near the engine which in turn exposes them to the effects of heat generated by the prime mover. Experience has been that in tanks operating under desert environments, the average life of a battery will be about one year due to the constant evaporation and resulting use under less than optimal conditions. This short life span results in high replacement and maintenance costs. In addition, to increased cost, the decrease in readiness represents an increase in risk to the troops. 
     It would be desirable to have a battery supporting and protecting structure that will help maintain the batteries near the ambient temperature even when the surrounding portion of the vehicle gets overly heated in order to save battery life and increase readiness. It would be further desirable to insulate the battery supporting structure to minimize heat transfer from the surrounding area into the battery support during prime mover operation. Still further it would be desirable to have a structure that will have increased ventilation as a function of temperature in the battery storage area. Yet another desirable feature would be means to remove a substantial portion of any dust or other air born matter entering the ventilation system. Battery compartment ventilation minimizes dust accumulation, lowers battery temperature, and evacuates explosive hydrogen gas created during battery charging. 
     SUMMARY OF THE INVENTION 
     Briefly the present invention is directed to a battery storage system for holding and protecting the storage batteries used in an armored combat vehicle. The storage system includes a battery case having a top, bottom, sides and ends so as to form an enclosure that holds the batteries in a spaced configuration within the case. The sides and top of the case are insulated so as to minimize the thermal effects caused by heat from the surrounding engine components and armor materials. A supporting grid supports the batteries apart from the case bottom to permit the circulation of air under and around the batteries for cooling purposes. The case has a thermally controlled valve member located near a first end of the case on the case&#39;s top surface. A conduit connects a second end of the battery case distal the valve member to an inlet on the vehicle&#39;s surface that allows the entry of ambient air. A solids entrapping means is located between the battery box and the inlet, the solid entrapping means being adapted to passively separate solids from the flowing air prior to entry of the cooling air into the case. 
     In a battery storage box according to this invention when the battery case temperature exceeds a predetermined value the valve opens allowing ambient air to flow through the conduit and around the batteries reducing their temperature. The cooling air first passes through the solids entraining means to minimize the solids that enter the battery enclosure. 
    
    
     BRIEF DESCRIPTION OF THE DRAWING 
     In the accompanying drawing: 
     FIG. 1 is top view of one embodiment of this invention; and 
     FIG. 2 is a sectional view taken along the line  2 — 2  of FIG.  1 . 
    
    
     DETAILED DESCRIPTION 
     Referring to the accompanying drawing in which like numerals refer to like parts and initially to FIG. 1, a battery storage system  10  is designed to hold and protect a plurality of storage batteries  12  used as part of an electrical system (not shown) of an armored combat vehicle. The storage system includes a battery case  14  having a top  16 , bottom  18 , sides  20  and ends  22  so as to form an enclosure that holds the batteries  12  in a spaced configuration within the case  14 . The sides  20  and top  16  of the case  14  are formed with an thermally insulating layer  24  that will minimize the heat transfer from the engine compartment that houses a large prime mover such as a 1500 horsepower turbine or diesel engine. Such engines generate a large amount of heat in the engine compartment that in turn stresses the batteries  12 . The insulation layer  24  also resists heat transfer from surrounding armor material that can absorb large amounts of heat when exposed to direct sun such as in desert environments. 
     The case is formed with a supporting grid  25  disposed along the bottom  18  of the case to support the batteries in a spaced relationship to the case bottom. This configuration permits the circulation of air under the batteries and the sides  20  of the case are spaced apart from the sides of the batteries  12  so as to allow free circulation of air around the batteries for cooling purposes. 
     The top surface  16  of the case  14  has a plurality of inlet apertures  26  formed in the surface near one end. The apertures  26  are connected to a manifold  28  that is in turn connected to a duct  30  with an inlet  32  located at the armored surface of the vehicle so as to admit ambient air. Air traversing the conduit  30  will pass through manifold  28  and apertures  26  into a particle separation chamber  34  formed on one end of the case  14 . The particle separation chamber  34  is formed by one battery case end  22  part of the top  16  and sides  20 , and bottom  18  of the case with the last side formed by a baffle  36 . The baffle  36  has an opening  38  located at a position above the bottom  18  of case  14  so as to form a shallow retaining pocket at the lower end of the chamber. Dirt and dust carried by the ambient air as it traverses the manifold  28  will tend to settle from the flow of air as the air changes direction passing through chamber  34 . The dust and dirt will collect in the retention pocket  39  and can be removed when periodic maintenance is performed on the battery case. Cooling air enters the remainder of the battery case  10  through the opening  38  where it circulates freely around the batteries  12 . 
     The top  16  of casing  14  distal the particle separation chamber  34  has a second plurality of exhaust apertures  40  formed in end of the top distal the inlet apertures  26 . Flow through the exhaust apertures  40  is controlled by means of a bimetallic cover  44 . The bimetallic cover  44  is formed so to lie essentially flat on the upper surface of case top  16  when the temperature of the battery case  10  is below a certain predetermined operating temperature e.g. 100 F. As the temperature rises above the set point, the cover  44  will open and allow cooling air to flow through the battery case  14 . As the temperature continues to rise, the cover  44  will open further to allow greater cooling capacity as the temperature rises. 
     As a further feature, the system can be enhanced as shown in FIG. 1 where the exhaust cover  44  and apertures  40  are surrounded by an exhaust manifold  46  that has an associated fan  48  located within an exhaust duct  50 . The fan  48  is controlled by a sensing element  52 , which will signal a control box  54  the control box activating the fan  48  to cause the fan to operate when the temperature measured by sensing element  52  in the battery case  14  reaches a level where additional cooling air is indicated. 
     Various alterations and modifications will become apparent to those skilled in the art without departing from the scope and spirit of this invention and it is understood this invention is limited only by the following claims.