Battery assembly with kinetic energy-based recharging

A mobile electronic device configured to recharge when oscillated. The electronic device includes a housing with a battery compartment and a battery assembly positioned within the battery compartment. The battery assembly includes a rechargeable storage battery connected to device's battery contacts. The battery assembly includes a charging assembly connected to the rechargeable storage battery, and the charging assembly provides a kinetic energy-based generator operating during the oscillating motion of the electronic device to output electrical current to the rechargeable storage battery. The generator includes: (a) a barrel; (b) a permanent magnet positioned in an elongated chamber of the barrel and sliding within the chamber during movement of the device; and (c) a coil of conductive wire wrapped around an outer surface of the barrel. The chamber, generator magnet, and barrel outer surface receiving the coil all may be non-circular in cross sectional shape or non-cylindrical to improve kinetic energy harvesting.

BACKGROUND

1. Field of the Description

The present description relates, in general, to batteries and/or general power supplies/sources including replacement of rechargeable and non-rechargeable batteries with a device that continuously provides power or at least provides an extended/extendable life. More particularly, the present description relates to a battery assembly that may be used in nearly any electronic device, such as a mobile phone, a digital camera, a portable audio device, or the like, to replace traditional batteries. Briefly, the battery assembly is configured to harvest kinetic energy or power to generate electricity and charge a rechargeable battery.

2. Relevant Background

Today's world is full of electronic devices as everyone seems to be continuously using, or at least carrying, these devices to stay connected with other people and world events, to capture their experiences, and for nearly continuous entertainment. The trend is toward more and more digital devices being used by people in both developed and developing countries. These electronic devices include, but are not limited to, mobile or cell phones, global positioning satellite (GPS) devices, portable audio devices, video games, portable/personal computing devices such as tablets and pads, and digital cameras.

While providing great convenience and connectivity, an ongoing problem with the use of electronic devices is how best to power them on an ongoing basis and while their users are themselves mobile. Most portable electronic devices are powered, at least periodically, with onboard batteries. Due to cost and environmental concerns, traditional disposable (or non-rechargeable) batteries are being replaced in large part by rechargeable batteries. Also, significant efforts have been made to increase the life of batteries.

Unfortunately, though, a number of issues still face the designers and users of portable electronic devices. An issue with all of these devices is that the more people use and rely on them the more quickly they use up the power stored in their batteries and “go dead” often when the device is needed the most. For example, a mobile phone may lose battery life when a motorist is stranded on a remote highway. Battery technology in general has not changed in over fifteen years. The size and capacity ratio to power density has stayed the same while the devices these batteries power have gotten progressively smaller. Thus, a wall or hurdle will soon be reached at which point electronic devices will be limited in their size (e.g., cannot be made any smaller) due to battery capacity restraints and not due to manufacturing/design issues.

Recharging technologies are also improving but, for the most part, each requires that the user plug their device into a wall socket or remove the battery and place the battery into a charger that is plugged into a wall socket. As a result, users of portable electronic devices are tethered to walls (or automobiles) as the only effective way to bring their devices back to life or a full power state. Further, each device may have a different charger such that the user is carrying or using multiple charging devices, which can be lost or misplaced.

These recharging techniques and devices are cumbersome as well as only providing a stop gap resolution to the ongoing problem that the power bar or battery indicator on each electronic device is always moving toward a low or no power state until the device is again plugged in to an external power source. This is a frustration for many users because the devices may be used all day without the users returning to a location where recharging is possible. The electronic devices are designed and intended to provide mobility and are hand/pocket size so that they can be carried on one's person at all times, which has led to the development of many holsters and similar devices to facilitate carrying these devices in a hands-free manner. However, the mobile design intent is hindered by forcing users to only recharge with a car electric system or with a wall-mounted charger/socket.

There have been many attempts at developing alternative battery chargers that would support a more mobile use and recharging. For example, some chargers have been developed that make use of solar energy in a battery charging device. While desirable from the point of a renewable energy source, solar technology chargers are often standalone or separate devices that are the size of the electronic device they are used to charge, which makes them an added and often undesirable burden for the device users or consumer. Specifically, the user has to carry two devices rather than one (similar to many wall-type chargers). Further, solar chargers typically only work, well in bright sunlight, which makes them only sporadically useful (e.g., not useful when raining or as useful on overcast days) and not useful at all during portions of each day (e.g., nighttime).

Another device that may be used as a battery charger is the crank dynamo-based charger. These have not been widely adopted in part because they have a relatively large form factor such as at least as large as the device they are being used to charge. Additionally, charging only occurs while the crank is being vigorously rotated or cranked, which can be impractical for many users (e.g., cannot charge while using hands for any other activity such as talking on a mobile phone). In other words, the user must stop what they are doing and crank on the charger until the battery in the device is again at usable power levels. A further limitation with such chargers is that there are many points of failure, such as gear drives that may take the form of nylon interlocking gears, which may require periodic maintenance or replacement of parts or the chargers.

Hence, there remains a need for improved methods and devices for recharging batteries that are used in existing and to-be-developed, portable or mobile electronic devices. An issue with both solar and dynamo-based charging devices is the fact that they present a relatively large separate device that the user must carry around with them to be able to charge their batteries or devices. Another issue with these and wall socket/car electric system-based chargers is that the user has to actively operate them or otherwise stop using the mobile device as intended (e.g., in a mobile manner). The user cannot simply affect charging while they are living their life as normal and performing typical daily activities such as walking down the street or through an airport or mall. With these issues in mind, it would be preferable that the new charging devices and methods be designed to have a minimal additional form factor or even work within the form factor of the original electronic device and be designed to provide recharging power (or electricity) without extraordinary user intervention or action (e.g., the device may be used as a mobile device and the user may carry out typical daily activities).

SUMMARY

To address the above and other needs, the present description describes a battery assembly (and personal/mobile electronic devices including such an assembly) that includes a rechargeable battery and charging assembly. The charging assembly is configured to convert kinetic and/or potential energy into electricity (e.g., harvest kinetic energy) that can be used to charge the rechargeable battery. The battery assembly may be designed to have a form factor similar to existing batteries of electronic devices such as a thin, rectangular shape as common in many mobile phones or a cylindrical shape common for AA, AAA, and similar batteries.

In this regard, the battery assembly may be thought of as a battery replacement for traditional rechargeable and non-rechargeable batteries that is able to create electricity from human motion while presenting an extremely small form factor. The charging assembly or mechanism can create electricity both from intentional motion (e.g., shaking the mechanism back and forth in an oscillating manner) and unintentional or indirect motion (e.g., a user holding/carrying an electronic device with the battery assembly performing an activity such as walking, running, riding a bike, and other typical daily activities performed by users of electronic devices).

The kinetic energy-harvesting charging assembly uses the theory behind Faraday's law of induction to create the power and/or electricity useful for charging a battery. Briefly, Faraday's law states that when magnetic forces are changed an electric current can be created, and the amount of current that can be created is also directly related to the change in the magnetic field and the size of the field. Hence, when the magnetic field increases in magnitude so does the amount of voltage that can be created. This is typically called magnetic flux, which is equal to the surface area of the magnetic field multiplied by the strength of the field.

In the past, others have made attempts to produce Faraday-based charging devices, but these have not been widely adopted and have not met the demand of makers and users of personal electronic devices. Prior Faraday-based charging devices are typically relatively large such that they cannot be used within existing devices as a replacement for traditional batteries (e.g., their form factor is much larger than that of existing batteries). As a result, these devices are similar to existing chargers such as dynamo-based chargers that have to be carried about separately by the user and then periodically connected to the device such as during exercise to oscillate the charger.

The inventors have recognized that prior Faraday-based chargers have to be relatively large in size to provide useful amounts of electricity, and the inventors believe that this size limitation is caused, in part, by the use of cylindrical magnets. In a typical design, the cylindrical magnet is positioned, to be able to slide, within a cylindrical bore/chamber of bobbins/housings about which copper wirings are wrapped. The magnet moves relative to the windings when the charger is shaken or moved by its user, which causes electric current to flow in the windings/wires.

The inventors further recognized that use of a cylindrical magnet limits the amount of efficiency by limiting the amount of windings that can be provided in a small area, limits the shape of the charger (e.g., hard to fit a cylindrical device into a flat/rectangular electronic device housing), and limits the form factor in which these chargers can be fit. Another limiting aspect of these chargers is that they can only be actively charging a battery when they are actively and, often, rigorously shaken. Magnet movement may be facilitated by use of a mechanical spring, but the spring creates a mechanical failure point that can fatigue over time. In summary, these devices are plagued with large size constraints, usability problems (similar to a dynamo-based charger requiring user actions), and electrical and magnetic efficiencies, and these concerns have limited the development of Faraday-based chargers.

With these design flaws understood by the inventors, the charging assembles described herein generally make use of permanent magnets that are non-cylindrical in shape (i.e., do not have a circular cross section). Prototypes fabricated with elongate magnets having triangular, rectangular, and other multi-sided cross sectional shapes have been proven to provide much higher charging outputs than those obtained with a cylindrical magnet of similar size.

For example, a charging assembly was fabricated that included a barrel with a rectangular chamber or bore, and a bobbin or reel was provided on an external surface or portion of the barrel. Copper wire or any other non-ferrous, electrically conductive material was wound or wrapped about this bobbin, and the barrel and bobbin were fabricated of a non-conducting or non-ferrous material (e.g., a plastic, ceramic, glass, or the like). A permanent magnet with a flat rectangular shape was positioned within the chamber/bore and allowed to slide up and down the length of the chamber/bore with oscillations or shakes of the barrel. It was found that 200 shakes or steps provided a charging output of 0.25 volts at 220 mAh while 1200 shakes or steps provided 3.00 volts at 1320 mA (at a time of 6 minutes of jogging while carrying the charging assembly or otherwise shaking the assembly), which is significant as a survey of power specifications for existing mobile phones indicated an average power requirement or battery load of about 1360 mAh (or near to what one initial prototype provided during testing).

The inventors believe that one reason that non-cylindrical magnets are desirable is that there are more edges/corners providing thinner separations between the winding/copper and the moving magnet (less insulating or non-ferrous material between the windings and the magnet). The output may also be improved due to other design factors such as increased field strength, more area of wire/windings and magnet, and the like. With a polygonal shape, one can achieve a ratio of magnet to copper wire that is much closer to fifty percent each because the surface area a polygon can afford versus a cylinder. In manufacturing as well, it is much easier to injection mold a polygonal shape versus a cylindrical one. Because of this aspect, the walls of the bobbin can be manufactured much thinner, which allows the magnet closer proximity to the copper wire. The output may also be improved due to other design factors such as increased field strength, more area of wire/windings and magnet, and the like.

More particularly, an electronic device, such as mobile phone or other portable/personal electronic device, is provided that is adapted for generating and storing charge during oscillating motion (e.g., kinetic energy harvesting to provide ongoing recharging during typical daily activities of the device's user/owner). The electronic device includes a device housing with a battery compartment that includes battery contacts or leads of the electronic device and/or that are connected to loads of the device. The electronic device also includes a battery assembly positioned within the battery compartment.

The battery assembly has the form factor of a conventional battery that would typically have been positioned in the battery compartment, and the battery assembly includes a rechargeable storage battery connected to the battery contacts. For example, this may be a Li-ion battery or the like, and it may be about half the size as a conventional battery positioned within the battery compartment. The battery assembly also includes a charging assembly electrically connected to the rechargeable storage battery. The charging assembly including a kinetic energy-based generator operating during the oscillating motion of the electronic device to output electrical current to the rechargeable storage battery.

The kinetic energy-based generator may include: (a) a barrel with a chamber extending a length of the barrel; (b) a permanent magnet positioned in the chamber and sized and shaped to slide relatively freely within the chamber during the oscillating motion; and (c) a coil of electrically conductive wire wrapped around the barrel and the chamber. In operation, the permanent magnet travels in and out of an interior region of the coil as it slides in the chamber and, in response, the output electrical current is generated within the coil. Significantly, the chamber and the permanent magnet both have a non-circular cross sectional shape. The inventors found that more edges and sides created a more uniform wall thickness in manufacturing as well as affording a closer physical proximity between the magnet and the copper windings. This, in turn, yields much more energy in a smaller space or form factor. For example, the non-circular cross sectional shape of the chamber and the generator magnet may be one of a rectangle, a square, a triangle, a hexagon, or another polygon.

To achieve desirable current generation, the coil has a height as measured along an axis of the chamber and the permanent magnet has a height that is selected from the range of 70 to 100 percent of the coil height. Further, the chamber has a width and a thickness that are each about 0.005 to 0.010 inches greater in magnitude than a corresponding width and thickness of the permanent magnet (e.g., to provide very close proximity between the magnet and the coil). Similarly along these lines, the barrel has a sidewall defining the chamber, and the sidewall is formed of a nonferrous material that has a thickness along a bobbin section receiving the coil that is less than about 1/32 inches thick. In some embodiments not only do the chamber and generator magnet have non-circular cross sections, but the sidewall at the bobbin section has cross sectional shape taken transverse to the axis of the chamber that is non-circular with corners and sides matching corners and sides of the chamber. In this way, the coil has a first thickness proximate to one of the corners that is less than a second thickness proximate to one of the sides.

In some embodiments, one void portion of the chamber is provided to receive the generator magnet as it slides out of the coil's interior region. In other cases, the chamber extends a portion of the length of the barrel such that the permanent magnet travels into a first void outside the interior region of the coil at one end of the coil and into a second void outside the interior region of the coil at a second end of the coil. In some preferred embodiments, the kinetic energy-based generator further includes spring magnets (one, two, or more) positioned at opposite ends of the chamber, and the spring magnets each are made up of permanent magnets with poles arranged to oppose poles of the permanent magnet in the chamber (e.g., like poles are positioned adjacent each other to cause a spring-like effect as the magnetic fields interact in the chamber as the generator magnet slides back and forth within the chamber). This methodology can also be created in other form factors and designs. The methods include, but are not limited to, rotational motion with induction and “gyroscope-like” motion with spin axis and motor.

To achieve useful and surprisingly good results for charging based on kinetic energy harvesting, the conductive wire of the coil may include at least 300 turns of No. 38 AWG or finer copper wire. Similarly, the coil is formed to have a height and the permanent magnet is chosen to have a particular height and gauss rating such that the output electrical current to the storage battery is at least about 1300 mAh at about 3 or more volts when the oscillating motion is at least about 1000 to 1200 shakes of the electronic device.

Because of the power density this device can achieve, it can be scaled up or down depending on the form factor criteria. Larger devices such as vehicles, tools, heavy machinery, and the like would likely benefit from larger versions of this invention (than shown and described in more detail in the detailed description and accompanying figures) and have the physical real estate to house the larger versions comfortably. In contrast, though, cellular phone, medical equipment, and apparel would necessitate or benefit from the more miniature versions of the described technology. All form factors, large or small, are considered a part of this invention and covered by this description and included claims, and each of these form factors for the battery replacement devices may achieve the described yield and would benefit from the same high power density.

DETAILED DESCRIPTION

Briefly, embodiments taught in this description address the above described issues with prior battery chargers and attempted replacements for conventional batteries. Battery assemblies are presented herein that include kinetic energy-based charging assemblies that can be thought of as a battery replacement that can actively charge itself from benign or typical human activities.

Many of the embodiments are designed to fit into places (e.g., within a mobile/personal electronic device) of the same size constraints and form factors as regular rechargeable and non-rechargeable batteries. The batteries being “replaced” may include (but are not limited to or are scalable beyond) standard AA, AAA, 9V, D, C, proprietary rechargeable batteries for personal audio/visual devices, cell phone rechargeable batteries, and GPS-device rechargeable batteries. The battery assemblies typically will include a rechargeable battery and embodiments where the battery assembly is added to any of the above devices a battery is provided that will charge itself. The method of charging is a direct result of both unintentional human motion (such as walking from meeting to meeting while holding, wearing, or carrying the electronic device in which the battery assembly has been installed) and intentional human motion (such as shaking one's cell phone up and down to oscillate a non-cylindrical generator battery within a kinetic energy-based generator). Both activities have equal or similar efficiencies for use/operation of the generator battery replacement.

Briefly, before turning to the figures and particular examples, the charging assembly or its kinetic energy-based generator may be thought of as including a plastic or other non ferrous-material bobbin (or a barrel/tube, providing a magnetic chamber defining a sliding travel path for a permanent magnet, with an added or integral bobbin or spool for receiving a copper wiring or windings forming a generator coil). The bobbin may be a rectilinear shape, a square, a rectangle, a hexagon, or the like—or, basically, any shape with a non-circular cross sectional shape. The bobbin has a bottom portion or extension with short wails protruding out (a bottom portion of a barrel that houses/retains/guides the magnet) and a top portion or extension with the same shaped short walls protruding out (a top portion/end of the barrel that retains/guides the magnet). In the generator, there is copper wire (or other electrically conductive wire) which may be No. 38 AWG or thinner that is wrapped or wound around the bobbin in between the top protruding wall and the bottom protruding wall (e.g., in this embodiment, the coil is formed on a mid section of the bobbin in a specially formed reel/spool or about the bobbin's barrel in which the magnet travels). These walls act as both an alignment as well as a confinement aid for the wrapped copper wire.

The copper wire is wrapped with a number of windings and a height (as measured along axis of chamber holding the generator magnet) each falling within a preset range of values, which are set based upon the shape and size (outer diameter and length, which will determine the available travel distance for the magnet) of the bobbin. For squares and rectangles, the minimum number of turns can be, but is not limited to, about 300, and, as for triangular and hexagonal bobbins, less winding or turns may be sufficient such as 200 to 300 windings or turns of the wire over a preset length or height.

In the generator, there is an open tube portion or chamber in the bobbin (or in the barrel to which the bobbin is attached or in which the bobbin is integrally formed). The chamber typically has the same profile or cross sectional shape as the bobbin sidewalls/exterior surfaces of the reel/bobbin where the copper wire is located/wound, but the chamber is simply an empty void defining a travel path. Inside the chamber/tube portion of the bobbin is a permanent magnet such as a rare earth, neodymium, or other magnet that is bipolarly magnetized at the top and bottom. Its profile or cross sectional shape is the same as the bobbin's chamber/tube portion yet its outer dimensions are just a fraction smaller so as to fit inside the bobbin and glide freely (typically down to a 0.005 inch clearance or some relatively tight clearance).

During operation, the permanent or generator magnet travels within the chamber next to or within the generator coil/windings portion and then out of the coil/windings portion into spaces/voids of the chamber in the top and bottom portions of the bobbin or barrel such that the magnetic field changes, and based on Faraday's laws regarding induction, to cause electrical current to flow in the wires of the coil/windings portion and charge an electrically connected rechargeable battery.

To facilitate oscillation without as much human manipulation/input, the generator may include on the top and bottom of the bobbin smaller permanent magnets (e.g., neodymium magnets that can be about 2 mm in outer dimension (or more or less depending on the form-factor of the device)). These “spring magnets/magnetic springs” are oriented with opposing poles facing the same poles as the large neodymium or other permanent magnet in the center of the bobbin's chamber/tube (e.g., like poles of the generator magnet and the spring magnets face toward each other within the bobbin structure). The interaction of the magnetic fields of these magnets acts as a natural solid state “spring,” which keeps the generator magnet buoyant or relatively neutral within the bobbin. Any movement large or small of the bobbin, such as a user walking while wearing an electronic device in which the charging assembly is installed, will make the generator magnet freely slide within the chamber of the barrel/bobbin so that it oscillates into and out of the copper coil windings in a repeated manner to generate current for charging a battery.

The shapes of the bobbin (e.g., the chamber and sidewalls receiving the conductor wire) and the magnet are key design features of the kinetic energy-based generator (recharger). These shapes are chosen to provide electrical and magnet efficiency of the device and, significantly, at a small form factor useful for providing a replacement battery rather than requiring a standalone or separate charger that has to be toted about by the user. Generally, the chamber and bobbin external sidewalls are non-circular in cross sectional shape (in contrast to prior devices using a cylindrical tube and bobbin and a cylindrical magnet).

For example, the generator magnet may have a rectangular cross section and overall shape. The inventors have proven with prototypes that having a rectangular magnet inside a rectangular bobbin allows for more windings to be provided in a smaller form factor than if one were to use cylindrical magnets and bobbins. The inventors recognized that charging assemblies are able to yield/harvest more energy from a Faraday-based device the more magnet (e.g., magnetic surface area) they have and the more copper (e.g., conductor material) they have at a closer proximity to one another. The shape and arrangement of the various components of the charging assembly, such as copper windings, generator magnet, and bobbin (reel/spool sidewall shapes, chamber cross sectional shape, and the like) make for more voltage yield in a smaller form factor, which allows it to be used within an electronic device rather than as a separate/outside device that has to be connected and oscillated to affect charging.

In a complete battery assembly, a lithium-ion rechargeable battery pack is placed on top or to the sides of the bobbin. The battery pack may have the same voltage output as the battery in which the device is replacing, i.e., if the battery assembly (or battery replacement apparatus) is replacing a cell phone battery then the Li-ion battery pack adjacent to the charging assembly is 3.7 Volts because most cell phone batteries are 3.7 Volts. In some embodiment, the current-per-hour output of the device may be lower than the battery it is replacing due to the smaller form factor of the Li-Ion pack (e.g., the charging assembly takes some of the space previously used for the battery of the electronic device). A typical cell phone battery will be 3.7 Volts at 1440 mAh, whereas the above-mentioned prototype device may be 220 mAh at 3.7 Volts.

Significantly, though, this current output typically does not affect the user because, when the electronic device and its “integral” or “embedded” battery charging assembly is in motion, the device is perpetually recharging its milliamp per hour output yield from the Li-ion battery with charging electrons from the kinetic energy-based charging assembly. Effectively, the user will never bottom out the current of the Li-ion battery (or rechargeable battery of the battery replacement apparatus) because the rechargeable battery is being refilled/recharged on an ongoing basis.

FIG. 1illustrates a functional block or electrical circuit/block diagram of an electronic device100, such as a mobile phone, GPS device, portable video game, digital camera, or the like. The electronic device100includes a “replacement battery device” in the form of a charging assembly110combined with a rechargeable storage battery120. For example, the charging assembly110and storage battery120may be designed to have a form factor that matches an existing electronic device battery such that this conventional battery may simply be removed and replaced with the charging assembly110and storage battery120(with or without modification of the other components of the device100such as its housing to receive and retain the battery replacement apparatus).

The rechargeable storage battery120(e.g., a Li-ion battery or the like) is electrically connected to one or more loads130of the electronic device100such that the battery120supplies electricity used by the electronic device100. The rechargeable storage battery120is electrically connected at its positive and negative connections122,123to the charging assembly110such that during operation of the charging assembly110(e.g., when the electronic device110is shaken or oscillated as may occur during sedate movements such as walking and more active movements such as running or rigorous, intentional shaking for a quicker charge) current118is provided to the battery120for storage or for use via leads134by device load130. The storage battery120acts as a ballast to keep energy that has been generated within the generator112for continuous and/or extended ongoing use by the load130. The storage battery120may be a capacitor, a Li-ion battery, a nickel cadmium battery, or other electrical storage device.

Typically, the current118is DC current, and the charging assembly110includes components to convert and condition (if necessary) the current it produces to useful DC current118. For example, at114, the charging assembly110is shown to operate to output raw electricity114from the kinetic energy-based generator (e.g., a copper windings/bobbing generator)112in the form of alternating or AC current. An AC to DC converter116is provided in the charging assembly110in this exemplary, but not limiting implementation, in the form of a bridge rectifier (or diode bridge), which very efficiently changes the raw AC current114from the generator112to usable DC or direct current118that can be supplied at connections122,123to the storage battery120. A Zener diode or similar device (such as a flyback diode)119may be provided, such as on the positive lead/output line of charging assembly110as shown, so as to create an electrical one-way valve such that electricity only flows in one direction and not back into the generator112from the battery120.

A key feature of the charging assembly110is the kinetic energy-based generator112that outputs current114when the device100and included charging assembly110are oscillated or undergo relatively small amounts of motion. The generator112may, in simple terms, be considered a Faraday-based generator that includes a bobbin with exterior sidewalls and an internal chamber/bore with a non-circular profile or cross sectional shape. Further, generator112includes a permanent magnet of a shape similar to but smaller than the internal chamber such that, when copper windings or a coil is provided on the bobbin's exterior walls and the magnet moves in and out of the region of the chamber adjacent or within the coil, electrical current is generated as shown at114.

In some embodiments, the copper windings or coils formed of copper or other electrically conductive wire are formed from No. 38 AWG or thinner wire. The wire may be lacquered and wrapped or wound around a bobbin or spool (which is provided integrally or as an attached part to the generator barrel providing the chamber for guiding the permanent magnet that may be a rare earth magnet, a neodymium, or other permanent magnet) formed of non-ferrous material (such as a plastic bobbin/barrel combination part). In some cases, it has been found useful to use a minimum number of turns/wraps/windings of about 300.

FIG. 2Aillustrates an electronic device200(such as a mobile phone) with its back cover removed exposing its internal components (e.g., to show its battery compartment) whileFIG. 2Billustrates the electronic device as a side view with the housing sidewall(s) shown to be cut partially away to expose the internal components of the device200. As shown, the electronic device200includes the components taught herein that provide a battery replacement apparatus. Specifically, the device200has a housing/shell210with copper battery contacts212providing a connection to the device's battery load or the device's components that use current from the device's battery.

The replacement battery apparatus or battery assembly is provided by a storage battery214(e.g., a Li-ion battery or the like) and a kinetic energy-based charging assembly220(connections/wiring between components of the charging assembly220and the battery214are not shown for simplicity of illustration but will be understood by anyone in the electrical arts). The storage battery214is about one half the size of a conventional battery for the device212to allow room for the charging assembly220. In other words, the replacement apparatus has about the same size and form factor as the battery it is replacing while the charging assembly is less than about one half (or fifty percent the size), while still providing adequate current/power to run the loads of the device linked to contacts212. The battery214acts to keep the power constant for loads of device200and as a power ballast.

The charging assembly220includes an AC-to-DC converter226, which acts to convert AC output by the coils/generator windings234into DC that is then supplied to battery214. As noted above, the converter226may take many forms to practice the device200such as a bridge rectifier, a diode bridge, or the like. A Zener diode, flyback diode, or other device227may be provided to act as a one-way valve for electricity created by the generator such that the current flows into the battery214from the generator's windings234and not back into the windings234.

The charging assembly220includes a barrel or sleeve222that includes inner sidewalls or interior surfaces223that define a chamber or tube portion in which a generator magnet224is positioned and allowed to travel on an electricity-generating travel path. The barrel or sleeve222is shown to be rectangular in shape, and the inner sidewalls223define a chamber with a length, LChamber, that is about equal to the height of the barrel/sleeve222and with a thickness, tChamber, that is about equal to the depth of the barrel/sleeve222less the thicknesses of the walls of the barrel/sleeve222.

For example, the length, LChamber, may range from about 0.5 to about 3 inches (or more) while the thickness, tChamber, may range from about 0.15 to 0.5 inches (or more) for a typical electronic device200. The thicknesses of the sidewalls of the barrel222(and bobbin section230) may be very thin such as less than about 1/32 of an inch, with such thin walls being desirable to provide higher efficiencies of energy transfer between the copper windings234and the magnet224. The barrel or magnet housing222(as well as at bobbin section230) is formed of a non-ferrous material such as a plastic or other lightweight material.

The main generator magnet224is a permanent magnet, such as a neodymium magnet, with opposite poles arranged at top and bottom ends (ends facing the battery214and away from the battery214, for example). The magnet224is configured in the shape of a rectangle, but other non-cylindrical shapes may be used in other embodiments depending on the intended use that may limit or set acceptable size (outer dimensions) and form factors (e.g., a flat rectangular shape is useful when replacing a similarly shaped conventional cell phone battery whereas a replacement apparatus for a conventional cylindrical battery may be an elongate magnet with three or more sides (e.g., a polygonal cross sectional shape)).

The rectangular magnet224has a height, HMagnet, that is significantly less than the length, LChamber, of the chamber in magnet housing/barrel222such that it can travel or move about in the chamber to generate electricity. For example, the height, HMagnet, is typically less than about half the length, LChamber, and is often less than about one third (as shown). The height, HMagnet, of the magnet224is often chosen to be about equal to or less than (such 80 to 50 percent or less) of a height, HCoil, of the copper windings/coil234to allow the magnet224to move a greater distance in housing/barrel222(in and out of coil234) to generate more electricity.

The magnet224has a width or thickness, tMagnet, that nearly matches the width or thickness, tChamber, of the chamber defined by inner surface/sidewalls223. Typically, it is desirable to provide a very small clearance between the sides of the magnet224and the inner surfaces223of the barrel/magnet housing222such that the magnet224can freely slide or move225in the chamber but such that the surfaces of the magnet224are positioned as close as possible/practical to the coil234. For example, the thickness, tChamber, and width, wChamber, of the chamber formed by inner sidewalls223may each be about 0.005 to 0.010 inches (or more) greater than the thickness, tMagnet, and width, wMagnet, of the magnet224.

In the charging assembly220, the coil/windings234have a height, HCoil, that is chosen such that the magnet234is able to move out of the coil at both ends of its travel path in the barrel/magnet housing222. This causes electricity to be generated via induction twice during each travel cycle, e.g., each time the magnet234makes a full loop such as starting at the top of the chamber, dropping to the bottom of the chamber, and then returning back to the top of the chamber which causes it to pass through the coil/windings234twice. Specifically, the chamber in housing/barrel222has a length, Lchamber, that is three times as large as the height, HCoil, of the coil/windings234and the bobbin230is placed at the midpoint of the barrel/housing222and the defined chamber holding the magnet224. Further, the magnet224has a height, HMagnet, that is equal to or less than the coil height, HCoil.

As a result of this arrangement, the chamber in barrel222provided by sidewalls/interior surfaces223has first and second or top and bottom voids or spaces236,237. These spaces or voids236,237define spaces or areas of the charging assembly220in which the magnet224may travel in the chamber and move out of the interior of the coil/windings234. These spaces/voids236,237typically are at least as large as the magnet224such that the magnet224can be fully received within the spaces236,237(move out of the coil234). It is this transition that allows the charging assembly220to cause current to flow in the coil234into the battery214.

In the device200, the charging assembly220further includes one or more (two shown) upper (or first) spring magnets (or magnetic springs)228and one or more (two shown) lower (or second) spring magnets (or magnetic springs)229. These may be very small permanent magnets (such as neodymium magnets or the like) that are spaced apart at opposite ends of along the width of the end of the chamber in the barrel/housing222. The spring magnets228,229are arranged with magnetic poles opposite to the facing/adjacent poles of the generator magnet224facing inward to the chamber of barrel222. This creates a small repelling effect or force that makes the generator battery224relatively neutrally buoyant in the barrel/housing222. Such a magnetic spring effect at each end is desirable as it allows very little motion of the device200(or charging assembly220) to cause the generator magnet224to pass in and out of the copper windings234(into a position in the chamber of barrel222that is within or adjacent to the coil234and then out into the void/spaces236,237of the chamber).

The charging assembly220further includes a bobbin or spool230that is attached to or formed as an integral feature of the barrel/magnet housing222. The bobbin230has end walls232(in this embodiment) extending laterally outward from the barrel222a short distance to provide ends or stops defining a height, HCoil, of the coil or windings234. Conductive wire (such as copper wire that is no larger than about No. 38 AWG) is then wound, turned, or wrapped about the bobbin230between end walls232to provide a generator coil or windings234used to generate electricity due to interaction with the magnetic fields of magnet224. The coil/windings234may include wire wrapped at least about 300 times around the bobbin230, and this wire of coil234may be lacquered for insulation. Ends of the wire of coil234would then be electrically connected to the battery214via AC-to-DC converter226and diode227. As with the barrel/magnet housing222, the bobbin230is formed of a non-ferrous material such as a plastic, a glass, or a ceramic, and its thickness is kept to a minimum such as by forming it integrally with magnet housing/barrel222so as to position the wires of coil234as close to the traveling/moving225magnet224as possible/practical.

FIG. 3illustrates a perspective view of a charging assembly320that shows schematically operation of an exemplary charging assembly320that includes two end voids/spaces in the travel chamber and also that includes magnetic springs at each end of the chamber. The charging assembly320includes a bobbin or magnet housing330in which a bobbin or spool area is provided integrally on the outer surfaces/sides of the housing's sidewalls and the bobbin330includes inner surface/sidewalls331defining a chamber in which a generator magnet324is positioned and allowed to slide/travel325.

The outer surfaces or sidewalls of the housing/bobbin330are circular in cross sectional shape while the chamber defined by inner sidewalls331is rectangular. This may be useful where the form factor of the battery being replaced with the charging assembly320is a cylinder (e.g., an AA, AAA, or similar battery). As a result, a coil/copper windings334that are wrapped about a bobbin/spool portion (e.g., the midpoint/midsection) of the barrel/housing330form an inner surface or tunnel (coil passageway) that is cylindrical or has a circular cross section. In contrast, though, the chamber formed by sidewalls/surfaces331is rectangular (as was the case for charging assembly220), and the generator magnet324is also rectangular. The combination of a circular coil334and a rectangular (or polygonal) magnet324provides a large improvement in power/current generation efficiencies when compared with use of a cylindrical magnet with a circular coil.

The height of the coil334is chosen to be smaller (such as one third or less) than the overall height of the bobbin330(or at least of the chamber defined by sidewalls331) such that a top and a bottom void/space336,337are provided in the chamber of the bobbin330for the magnet324to travel during oscillation of the bobbin330. The generator320also includes upper and lower spring magnets360,362that may be cylindrical/button permanent magnets such as neodymium magnets that are much smaller than the main generator magnet324and are provided, as shown, with their poles of like polarity facing inward toward the generator magnet324(e.g., N poles of the spring magnets facing or adjacent the N pole of the generator magnet324). This causes the magnetic fields361,363of the spring magnets360,362to oppose and interact with the magnetic fields328,326, respectively, of the main generator magnet324(or at least when the magnet324travels325to a certain distance or separation spacing from such magnets360,362), which causes the main generator magnet325to be relatively neutrally buoyant in the chamber of bobbin such that very little motion causes it to move between voids336,337through the space within or portion of the chamber defined by sidewalls331within the coil/windings334.

The opposing magnet fields328and361,326and363may provide a relatively small repelling effect, but this allows the main generator magnet324to more readily pass in and out of the copper windings334regardless of gravitational pull. As a result, motions of a human/user holding, carrying, or wearing the charging assembly320such as walking, running, or simply going about daily activities is typically enough to make the magnet324shift325up and down in an oscillatory motion (up into the void336where it is repelled by field361of magnets360and down into the void337where it is repelled by field363of magnets362). The motion326of the main generator magnet324through and out of coil334is what generates electricity in coil334. Again, the windings/wires of coil334may be copper wires that are wrapped around the bobbin330at its midpoint, and the copper wire may be smaller than about No. 38 AWG wire and have 300 or more turns/wrappings about bobbin (a complete wrap of wire about the circumference of the bobbin330is a turn/wrapping or a winding).

FIG. 4illustrates a perspective view of another embodiment of a battery charging assembly420that may be utilized in an electronic device such as in the device200with battery214. As shown, the charging assembly420includes a barrel or magnet housing422that is generally rectangular in shape (e.g., a flat rectangular as typical of many electronic device batteries and battery housings in which the assembly420would be positioned in use). The barrel or housing422includes inner sidewalls423that define an interior chamber that extends the height or length of the barrel or housing422. The chamber is rectangular in shape and defines an electricity-generating travel path for a received generator magnet424, which too is rectangular in shape that matches that of the chamber with a small clearance provided to allow the battery424to freely slide in the chamber without binding. Specifically, the magnet424may be a permanent magnet that has a width much larger than its height and has a first pole facing upward (or a first direction) within the chamber and second, opposite pole facing downward (or a second opposite direction) within the chamber.

The charging assembly420further includes pairs of spring magnets428,429at each end of the chamber423of the barrel/housing422. Within each pair of the magnets428,429, the magnets (permanent magnets) are placed at opposite ends/sides of the chamber with their magnetic poles being opposite that of the closest pole of the larger, generator magnet424. This creates a very slight repelling effect that makes the main battery424neutrally buoyant in the barrel/housing422, which allows very little vertical motion to cause the magnet424to pass in and out of the copper windings/coil434.

In this regard, the assembly420includes a bobbin portion430on an exterior surface of the barrel/housing422. In this embodiment, the bobbin portion430is provided at one end of the housing422and its chamber423. A coil/windings of copper wire (e.g., No. 38 AWG wire) is wrapped (e.g., 300 or more times) about the bobbin portion430toward one end of the barrel/housing422, and the height of the coil434is set by an end wall/stop on bobbin430that provides a single (upper) void/space436into which the magnet424can travel when it moves out of or away from coil434.

For example, the chamber423may have a particular length and the coil/windings434may have a height that is less than this chamber length such that the magnet424can fully escape or travel out of the coil434to generate electricity in the coil434. The coil height may be about half or less of the chamber length and the magnet424may have a height that is also less than half of the chamber length (e.g., 40 to 50 percent of the chamber length in this example where the coil height is about 50 percent of the chamber length). In the embodiment of charging assembly420, the magnet424only generates electricity based on induction once per oscillation cycle (e.g., only passes both in and out of the coil424once as it travels from void436into the coil434and then back into the void436and out of the coil434).

In contrast to other embodiments, the charging assembly420further includes upper and lower (or first and second) elements490,495at the opposite ends of the chamber423of barrel422. These elements490,495may be piezoelectric elements that may be formed from sheets of piezoelectric material (e.g., a ceramic-based, aluminum-based, or other material). When this material is struck by the shifting magnet424, the elements490,495generate a small quantity of electricity. Hence, the elements490,495may be positioned within the chambers423of barrel422between the spring magnets428,429and the chamber422to allow such contact before the magnets428,429repel the larger magnet424. The electricity from the piezoelectric end sheet/elements490,495is fed into a bridge rectifier (or other AC to DC converter) as is the electricity from the coil434such that both “generators” can charge the storage battery (such as battery214ofFIG. 2) for improved charging capacity or efficiency. The battery would then have two generators feeding electricity to it, and since many kinds of piezoelectric materials are nonferrous by nature, the generator magnet424strikes it without sticking to it.

In some cases, it may be desirable to provide a replacement apparatus that may be used to replace a conventional cylindrical battery such as an AA battery, as these are used in many personal/portable electronic devices.FIG. 5illustrates a perspective view of a battery assembly505of the present invention that may be used as a replacement for this type of battery, andFIG. 6illustrates an exploded view of a portion of the charging assembly520of the battery assembly505showing a main generator battery524prior to insertion into a chamber of a barrel/magnet housing522.

The battery assembly505includes a battery housing or enclosure510with positive and negative contacts511,512typical of cylindrical batteries (such as an AA battery or the like). The enclosure sidewall510is shown partially cut away or removed so as to expose the internal components including a rechargeable storage battery514and a charging assembly520. In the battery assembly505, the storage battery514may by a cylindrical Li-ion battery or other rechargeable cylindrical battery. Typically, the battery514is chosen to fill all the space in housing510not taken up by the charging assembly520such as up to about 50 percent of the volume or as shown between about 30 and 40 percent (i.e., the battery514may have an outer diameter about that of the inner diameter of the housing510and a length/height of about 30 to 50 percent of the height of the housing510. The battery514is charged by current flowing from the charging assembly520, with connecting wires not shown for simplicity of illustration.

To this end, the charging assembly520includes a bridge rectifier, a diode bride, or AC-to-DC converter526that takes the AC current from the coil/windings534and converts it to DC current useful to the battery514. The charging assembly520also includes a Zener diode, a flyback diode, or similar device that functions to act as a one-way valve for the electricity created by the generator portion of charging assembly520so the current flows into the battery514but not back into the generator again.

The charging assembly520includes a barrel or magnet housing522that extends the length of the charging assembly520(e.g., about 50 to 70 percent of the length of the battery housing510), and the barrel522may have a circular-shaped outer wall but an inner wall/surfaces523may define a chamber or bore with a square cross section (e.g., equal or nearly equal sidewalls). The assembly520further includes a bobbin or spool portion530at an end of the barrel522and its chamber522, which in this case is opposite the battery514but this arrangement may be reversed to practice the invention. End stops532define the top and bottom of the bobbin530and, therefore, the height of the coil/windings534, which include copper wire (No. 38 or smaller gauge copper wire) that is wound or wrapped (300 or more times/turns) about the outer cylindrical shape of the barrel/magnet housing522in between the end stops532. In this manner, the bobbin530(or barrel522), which is made of a nonferrous material such as plastic, has a square void or chamber for a permanent magnet524to travel the length, LChamber, of the chamber523and in and out of the coil/copper windings534. The nonferrous material between the coil/windings534and the void/chamber523(and a contained magnet524) are typically minimized, such as less that about 1/32-inch to improve the efficiency of the charging assembly520(e.g., reduce spacing between magnet524and coil534, increase number of copper windings that can be provided in a particular space, and so on).

A generator magnet524is inserted into the elongate chamber523, and, in this embodiment, the magnet524is also elongate with a height (or length), HMagnet, that is much greater than its other dimensions. Specifically, the magnet524may have a height, HMagnet, that is about one half or some amount less than the length, LChamber, of the chamber defined within the barrel/magnet housing522by inner surfaces/sidewalls523. In other words, the magnet524is about the height of the coil534or bobbin portion530, and it may be square in cross sectional shape with an overall rectangular outer configuration. The chamber523of the barrel/magnet housing522has a length, LChamber, that is large enough that the magnet524is able to travel fully out of the coil534or as necessary out of coil534to cause electricity to inductively flow in coil534to the AC-to-DC converter526. The void536created or left in chamber523may be the same length/height as the height, HMagnet, of the generator magnet524to allow the magnet524to pass into the void536when it leaves the copper coil area534. In the charging assembly520, only one void536is provided adjacent one side of the coil534, but, in other embodiments, a void/space in the chamber may be provided at both ends as shown inFIG. 2. In one embodiment, the rectangular magnet524is chosen as it provides more electrical efficiency for the generator520than a cylindrical shaped magnet, and it takes the form of a neodymium magnet with a gauss rating of N42 or higher.

As with some other embodiments, one, two, or more spring magnets528may be provided at opposite ends of the barrel522in or near the chamber/bore defined by inner sidewalls523. These are arranged with their magnetic poles opposite to the nearer one of the poles of the generator magnet524. This creates a repelling or opposing effect as the generator magnet's magnetic fields interact with those of the spring magnets528, which enhances the free and more efficient movement of the generator magnet524with smaller or less rigorous movements of the battery assembly505.

At this point in the description, it may be useful to discuss more fully a variety of non-cylindrical shaped magnets (and corresponding chambers/bobbins) that may be used to provide enhanced kinetic energy capture or harvesting in a charging assembly of the present invention. Many cross sectional shapes may be chosen for the generator magnets with each generally having a polygonal cross sectional shape (e.g., three or more sides) and a height that is equal to or less than a coil/copper windings height (e.g., to maximize the interaction of the conductive element and the magnetic fields but not require a longer than necessary chamber or bore to move the magnet out of the coil).

FIGS. 7A and 7Billustrate an end view and a side exploded view, respectively, of a charging assembly720that includes a barrel or magnet housing722with a sidewall723defining outer surfaces and inner surfaces with a hexagonal shape. Hence, the chamber or bore has a hexagonal shape as does the bobbin portion (no end stops shown in this example), and an elongate permanent magnet with a hexagonal cross sectional shape (e.g., six outer walls or sides725) is used as the generator magnet724. A clearance729is provided between the outer walls/sides725of the magnet724and the chamber723such as less than about 0.005 to 0.010 inches. The magnet724has a height, HMagnet, that is less than the height, HCoil, of the coil734wrapped about the barrel722, e.g., 70 to about 100 percent of the coil height or the like. In this embodiment, two voids (one at each end of the coil734) are provided in the chamber723such that the chamber length, LChamber, is about three times the magnet height, HMagnet.

As shown, the charging assembly720utilizes a hexagonal copper winding734(at least at its core where copper wires abut the outer surfaces for the barrel/magnet housing722in the bobbin portion/section of the barrel722). As a result, there is much more surface area for the copper of coil734to be close to the magnet724, and this makes for a much more energy efficient Faraday-based generator720when compared with a cylindrical coil/magnet of the prior art. The hexagonal shape of the bobbin's outer surfaces (or outer surfaces of barrel in the bobbin section/portion) also affords more copper windings and a larger magnet724to fit into a smaller space than the cylindrical shapes of the prior art Faraday-based charger. The hexagonal generator magnet724(e.g., a hexagonal neodymium magnet) has more edges than a cylindrical magnet, and each of these edges/corners creates more surface area for the magnet724to be in closer contact with the copper windings of coil734, which yields more electricity in a smaller form factor.

FIGS. 8A and 8Billustrate an end sectional view and a side exploded view, respectively, of another charging assembly820that may be used in a battery assembly of the present invention. The charging assembly820includes a barrel or magnet housing822with a sidewall823that defines a triangular chamber and also a triangular profile for a bobbin section/portion of the coupling assembly820. An elongate permanent magnet with a triangular cross section is used for the generator magnet824(e.g., a permanent magnet with a pole at each end and with three sides (not counting the two ends). The coil834is wrapped or wound about the bobbin portion of the barrel822to form a hollow, elongated coil with a triangular cross sectional shape, and the coil834may be provided at the middle portion of the barrel822to provide for two voids/spaces for the generator battery824to slide out of the coil824when oscillating up/down or back and forth in the chamber823. A gap or space829is provided between the sides825of the magnet824and the inner surfaces823of the barrel822. Again, the generator magnet824may have a height that is about equal to (or somewhat less than) the coil height/length along the barrel822, and the chamber823may extend the entire length of the barrel822to be about three times the length of the coil834(or the magnet824).

In the assembly820, a triangular copper winding834is provided. There is much more surface area for the copper of the winding/coil834to be close to the magnet824for a much more energy efficient Faraday-based generator820than achieved with a cylindrical-type generator of the prior art. Again, the use of the triangular shape also affords more copper windings in coil834as a larger magnet824fits into a smaller space than was the case with the cylindrical-shaped magnets of the prior art devices. The magnet824may take the form of an elongate neodymium magnet with a triangular cross section, and this has more edges than a cylindrical magnet as used in prior devices. Each edge of the triangular magnet824provides more surface area for the magnet824to be in closer contact with the copper windings of coil834thereby yielding more electricity in a smaller form factor.

FIGS. 9A and 9Billustrate an end view and an exploded side view, respectively, of another embodiment of a charging assembly920of the present invention. The assembly920includes an elongated barrel922defining with its sidewalls923a bobbin section for receiving coil934that is rectangular in profile/cross and also a chamber that runs the length of the barrel/housing922that is rectangular in cross section. A small gap929, such as about 0.005 to 0.010 inches or the like, is provided between the magnet's sides925(four to provide a rectangular cross sectional shape) to allow the magnet924to freely slide within the chamber of barrel922. The magnet924typically will have a height/length that is about equal to or slightly less than the height of the coil934, and the chamber923of barrel922is shown to be about at least three times the height of magnet924such that the chamber923provides voids/spaces for the magnet924to travel outside of the coil934of the charging assembly920.

As shown, the charging assembly920provides a rectangular winding934(of copper wire at No. 38 AWG or the like). As a result, there is much more surface area for the copper of the coil934to be close to the magnet924, making the assembly920a much more energy efficient Faraday generator than the typically device utilizing cylindrical windings/coils. The rectangular shape also affords more copper windings in coil934as a larger magnet fits into a smaller space than the cylindrical prior art devices. The rectangular magnet (e.g., a neodymium magnet) has more edges/corners than a cylindrical magnet of a conventional Faraday generator. Each edge creates more surface area for the magnet924to be in closer contact with the copper windings/coil934, which yields more electricity in a smaller form factor.

FIGS. 10A and 10Billustrate a sectional end view and an exploded side view, respectively, of another charging assembly1020of the present invention. As shown, the assembly1020includes an elongate barrel or magnet housing1022with a sidewall1023defining a square outer profile/section in a bobbin/spool section where a coil1034is formed with copper wire or the like and also defining an inner chamber/bore that is square. The chamber is about three times the length of the coil1034and received a generator magnet1024. The generator magnet1024is also square with four exterior sides1025with dimensions nearly matching the interior walls1023of barrel1022such that there is only a small clearance/gap1029between the sides1025and inner surface of sidewall1023when the magnet1024is placed in the barrel's chamber to slide freely from end to end. The magnet1024has a length that typically equal to or slightly less than the coil length and the magnet1024typically can fully fit within voids in the chamber1023provided at either end of the coil1034(such as when the charging assembly1020is shaken or oscillated by a user).

In the assembly1020, a square winding1034is provided (e.g., of 300 or more turns/windings of copper wire). There is much more surface area for the copper of the winding1034to be close to the magnet1024, which makes for a much more energy efficient Faraday generator than the typical generator using a cylindrical winding. The square shape also affords more copper windings as a larger magnet is fit into a smaller space than was the case with the use of a cylindrical magnet and bobbin. A square neodymium or other material magnet1024has more edges than a cylindrical magnet, and each edge provides a location where more surface area is available for the magnet1024to be in closer contact with the copper windings of the coil1034such that more electricity is harvested or output by the charging assembly1020in a smaller form factor relative to a cylindrical-shaped magnet.

FIG. 11illustrates in more detail the charging assembly720ofFIGS. 7A and 7B, and it is intended to better show the improved proximity between the magnet and copper winding achieved with a magnet with a polygon cross section. As shown, the magnet724has a number of corners or edges1180that improve the efficiency of the assembly720. In part, this is because the thickness, t1, of the windings of coil734at edge1181of the bobbin/barrel722, for example, is less than the thickness, t2, at a side725of the magnet724(or polygonal shape).

In other words, the corners1180,1181in the magnets724and barrel/housing722where the coil734is wrapped/wound create more surface area and closer proximity for the magnetic field to affect the copper windings of the coil734, which causes the charging assembly720to be a more efficient generator. The many corners of any polygon make for more surface area for the magnet and copper winding to have a closer proximity.FIGS. 7A to 11show that any polygonal shape for the barrel/bobbin and coil (or copper windings) will yield an almost cylindrical outer shape when the copper windings are wrapped a desired number of times (e.g., 300 or more times). This creates more room for copper windings as well as more room for a larger magnet than the prior art, which relied upon all shapes to be cylindrical. The polygonal shape also provides more electrical generation in a smaller form factor (e.g., more efficient as obtain more output per unit of volume for the charging assemblies taught herein).

FIG. 12schematically and in simplified form illustrates how a user/operator1206may perform a typical daily activity, such as walking as shown with positions1210,1220, and1230, and cause a worn/carried charging assembly1222to generate electricity that can be used to charge a battery.FIG. 12assumes that the assembly1222includes “magnetic springs” as discussed above, and these are useful for making the generator magnet1224“buoyant” so that very small motion (a user1206walking from position1210to1230) creates oscillation1225,1227,1229of the generator magnet1224within the chamber of assembly1224.

The generator magnet1224is housed inside the bobbin and battery assembly or charging assembly1222.FIG. 12illustrates the assembly1222as it may be typically used, e.g., housed inside a wearable consumer electronic device such cell phone that may be in a pocket, holster, or the like of user1206. As shown at position1210, the magnet oscillation1225is shown to be working with a simple motion such as walking. This oscillation1225of generator magnet1224is due, at least in part, to the inclusion of the magnetic springs (not shown inFIG. 12but may take any of the forms discussed above with reference to the other figures). These magnetic springs create a neutrally buoyant environment in which the main generator magnet can freely oscillate1225with very little influence from gravity or friction within the barrel/bobbin's chamber. With the midstep in a walk cycle shown at1220, the magnet1224oscillates1227up in the device1222passing through the copper windings of the coil on the bobbin. This creates energy that is stored in the storage battery of the device1222for later use by the electronic device that houses the charging assembly1222. Then, with the downward step in the walk cycle shown at1230, the generator battery1224is oscillated1229downward. The magnet1224again passes through the copper windings of the coil on the bobbin, which creates more energy or causes electricity to flow to the storage battery for later use.

In one implementation, a cylindrical battery replacement is provided that is adapted for kinetic energy-based recharging. The battery replacement includes a cylindrical battery housing including a positive and a negative electrical contact at opposite ends and with a sidewall defining a cylindrical interior space. The battery replacement further includes a battery assembly positioned within the cylindrical interior space. The battery assembly includes: (a) a rechargeable storage battery electrically connected to discharge current via the positive and negative electrical contacts of the battery housing; and (b) a charging assembly. The charging assembly includes: (a) a coil of copper wire electrically connected via an AC-to-DC converter to the rechargeable storage battery to provide DC current to the rechargeable storage battery; (b) an elongate permanent magnet with a polygonal cross section transverse to a longitudinal axis of the permanent magnet; and (c) a magnet housing with a chamber for receiving the permanent magnet and with a bobbin about which the copper wire of the coil is wound. In practice, the chamber includes a first space within the coil and a second space outside of the coil such that the permanent magnet travels between the first and second spaces when the battery housing is oscillated back and forth along a longitudinal axis of the battery housing.

In this exemplary implementation of the battery replacement, the second space may have a length of at least about a height of the permanent magnet. In some cases, the bobbin may have an outer surface with a cross sectional shape matching the polygonal cross section of the permanent magnet, whereby the coil has a non-cylindrical interior space through which the permanent magnet passes during the oscillation of the battery housing. Further, in some implementations, the coil includes at least 300 turns of the copper wire and the permanent magnet and the coil have substantially equal heights. The polygonal cross section may be a triangle, a rectangle, a square, or a hexagon. Further, the charging assembly may include at least one spring magnet at each end of the chamber, and each of the spring magnets may include a permanent magnet with a pole positioned relative to the chamber to provide a magnetic field repelling a magnetic field of the permanent magnet when the permanent magnet is proximate to the spring magnet.

Still further, in some implementations, the charging assembly has a ratio of at least about 50 percent of the permanent magnet to 50 percent of the coil by volume. The permanent magnet may be a non-cylindrical rare earth magnet with a Gauss rating of N42 to N52. In some cases, the charging assembly further includes copper, ceramic, or aluminum piezo elements at opposing ends of the chamber. Then, the piezo elements are wired in parallel with the copper wire of the coil to the AC-to-DC converter, whereby additional secondary energy is harvested to improve electrical output and power density. For example, the power density or the electrical output of the cylindrical battery replacement may be improved by at least about 6 percent.