Abstract: The invention relates to a battery pack, especially for a hand-held power tool. Said battery pack comprises a battery housing (10) and an electronic unit (16) housed in said battery housing (10). The electronic unit (16) has one or more light sources (18). A first light-guiding element (28) can be inserted into the battery housing (10) and interacts with the at least one light source (18) in such a manner that the light emitted by the at least one light source (18) can be injected into the first light-guiding element (28).

Abstract: Various embodiments of the present invention are directed at a method and system for recharging batteries for wireless electronic devices. According to one embodiment, a rechargeable battery is adapted to couple with a wireless electronic device at a wide range of power parameters. The rechargeable battery includes a battery core configured to house battery chemicals that can be swapped when the battery core needs to be replaced. The battery includes a battery electrical component configured to monitor the battery core and configured to communicate with the electronic device using communications signals sent along an electrical path between the electronic device and the battery electrical component. The battery includes a battery end-cap configured to house at least a portion of the battery electrical component and a battery outer shell configured to fit over at least the battery core and configured to provide physical protection to at least the battery core.

Abstract: A management information display unit that is able to form management information for managing the power supply state of fuel cells and displays the management information while allowing the management information to be identified as to which electronic device pertains to the management information based on identification information inputted from a plurality of electronic devices that are able to output the formed management information in correlation with the identification information of the fuel cell, and an information transmitting part for transmitting the identification information and the management information while allowing the information to be inputted to the management information display unit are provided.

Abstract: A battery pack is constructed with a plurality of secondary batteries or a plurality of battery assemblies, each having a plurality of unit batteries, and at least one safety switch, which can facilitate precise measurement of the voltages of the plurality of secondary batteries or battery assemblies. The battery pack is constructed with a plurality of secondary batteries, at least one safety switch electrically connected between two adjacent batteries among the plurality of secondary batteries, and a plurality of sensing lines for measuring voltages of the plurality of secondary batteries. The quantity of the sensing lines is equals to a sum of the number of the secondary batteries, and the number of the safety switches, and plus one.

Abstract: Disclosed herein is a battery management system for lithium ion batteries capable of determining a battery pack's state of capacity; determining a battery pack's state of charge limits; adjusting for voltage drops and power losses over a battery's internal and/or connector impedances; adjusting the upper and lower voltage limits of a battery pack; and of actively balancing the cells making up the battery pack. In order to achieve this functionality, the battery pack management system includes an electronic control unit, which unit is coupled to module and cell-level circuitry that is designed to measure operating conditions of the battery such as voltage and current at any given time.

Abstract: Disclosed herein are a bus bar that simultaneously performs the electrical connection between a plurality of unit cells and the detection of voltage of the unit cells in a battery module having the unit cells mounted therein, wherein the bus bar includes: vertical bent parts formed by bending opposite ends of a strip-shaped bar body in the same direction, respectively, the vertical bent parts being provided with coupling grooves or protrusions; and a horizontal bent part formed by bending one of the vertical bent parts such that the horizontal bent part is parallel with the bar body, and a medium- or large-sized battery module including a plurality of unit cells, wherein the electrical connection between the unit cells and the detection of voltage of the unit cells are simultaneously performed using the bus bar. It is not necessary to use additional connecting members for detecting the voltage of unit cells when the bus bar according to the present invention is used in a battery module or a battery pack.

Abstract: Apparatus and methods for determining the individual states of charge of electrolytes in a redox battery with mixed or unmixed reactants by optical absorption spectrophotometry are disclosed. The state of charge thus obtained may serve as a gauge for the amount of electro-chemical energy left in the system. Further, the information on anolyte and catholyte charge states may be used for any rebalancing mechanism if the states are different.

Abstract: A battery module includes a plurality of flat cells and a plurality of nipping plates. Each of the flat cells has a cell main body and at least one electrode tab. The cell main body includes a power storage element sealed in a package member. The electrode tab is electrically connected to the power generating member and protruding outwardly from the cell main body. The flat cells are stacked on one another such that the electrode tabs are electrically connected in a stacking direction. Adjacent ones of the nipping plates in the stacking direction nip the electrode tab and a portion of the cell main body of a corresponding one of the flat cells from both opposite side surfaces of the corresponding one of the flat cells along the stacking direction.

Abstract: A portable electronics device comprises an interior space for storing a fuel vessel, and a chassis that includes at least one transparent window opposing the interior space.

Abstract: A method for determining characteristic variables for electrical states of an energy storage battery includes subdividing an electrolyte volume of the battery into at least two electrolyte volume components with associated electrolyte balancing areasabd defining at least two electrode plate balancing areas by subdividing the total resistance of electrode plates in the battery into resistance components for the defined electrode plate balancing areas and by subdividing the total energy storage capacity of the electrode plates into energy storage capacity components for the defined electrode plate balancing areas. The method further includes determining the electrolyte concentration of the electrolyte volume components for the defined electrolyte balancing areas and determining the amounts of charge which are held in the electrode plates in each of the electrode plate balancing areas. At least one characteristic variable for associated electrical states of the battery is determined using a mathematical model.

Abstract: Apparatus for filling the case (20) of a lead battery of the open type or of the sealed type with gas recombination, the case being filled with components for forming a gelled electrolyte, and the apparatus being characterized in that it comprises: at least two tanks (1, 2) containing said components, the first tank (1) containing sulfuric acid and the second tank (2) containing a mixture of water and a gelling agent such as particles of silica; at least two receptacles (4, 5) each connected to a respective one of the tanks (1, 2) and each containing a piston (10, 11) for expelling said components from said receptacles into pipes (17, 18); a mixer (16) into which said pipes (17, 18) open out; and a pipe (19) connecting said mixer (16) to the case (20) of said battery through the lid (21) of said battery.

Abstract: A battery strength indicating and switch means on a battery which is coupled across the terminals of the battery and which is provided with an indicating means to indicate the strength of the battery and in addition, the battery strength indicating means is also provided with an in-line switch which can easily be depressed to complete the circuit so as to place the indicator means across the terminals of the cell and display the charge of the battery.

Abstract: A method for recycling a battery pack is provided that enables a degraded battery pack to be replaced at a low cost while maintaining the advantages of a conventional sealed-type nickel-metal hydride secondary battery as being free from maintenance or leak of an electrolyte. The battery pack accommodates a battery module having a plurality of cells, which are a sealed-type nickel-metal hydride secondary battery, combined with each other. When the battery pack is judged as being degraded in a market, the battery pack is collected from the market as a battery to be replaced; a cell or battery module judged as being degraded is renewed by adding an electrolyte thereto; the battery module is installed in the battery pack again; and the battery pack is supplied as a replacement battery.

Abstract: A storage battery includes a battery casing, a cover closing an opening of said battery casing, and a thinner see-through window portion provided on a sidewall of battery casing for visual recognition, from the outside, of a level of electrolyte contained in battery casing. A rib for reinforcement is provided at see-through window portion.

Abstract: A small fuel cell (10) powers a portable electronic device (12) and contains a fuel reservoir (14) and a device (16) that measures the amount of liquid fuel (18) that is in the reservoir. The fuel cell operates on hydrogen that is obtained from a liquid hydrocarbon fuel, such as alcohol or other hydrocarbons. The liquid fuel is typically converted into hydrogen by a reforming process. The reservoir that is connected to the fuel cell has an indicia (19) that is readable by a human user of the portable electronic device, for measuring the amount of liquid hydrocarbon fuel that is present in the reservoir. Typically, the indicia consist of a sight glass, a capacitive element, a resistive element, a transparent portion of the reservoir, a float, or an acoustic transmitter coupled with an acoustic receiver.

Abstract: A device in accordance with a present invention includes at least one of a stainless steel anode and transition metal oxide cathode.

Abstract: A multiple-cell battery having a built-in controller is disclosed that extends the run time of the battery. The controller may extend the run time of the battery, for example, by converting the cell voltage to an output voltage that is greater than a cut-off voltage of an electronic device, by converting the cell voltage to an output voltage that is less than the nominal voltage of the electrochemical cell of the battery, or by protecting the electrochemical cell from current peaks. The controller may also include a ground bias circuit that provides a virtual ground so that a converter may operate at lower cell voltages. The battery may be a single-cell battery, a universal single-cell battery, a multiple-cell battery or a multiple-cell hybrid battery. The individual cells of the multiple-cell battery may be connected in series or parallel. In addition, the individual cells may have a controller in each cell that is capable of performing one or more functions to extend the run time of the cell.

Abstract: A fuel cell system cooperating with a rechargeable battery (18) mounts a fuel cell (12) as a source of motive power in an electric vehicle with an electric motor. The fuel cell system and the rechargeable battery (18) supplies the electric motor with electrical power. The fuel cell system also includes a reformer (11) as a source of hydrogen hydrogen-containing gas supplied to the fuel cell (12). The fuel cell system comprises a temperature sensor (19) for measuring the temperature (Tb) of the rechargeable battery and a controller (16) for controlling the response characteristics (mainly the response characteristics of the reformer) of the fuel cell system based on the measured temperature (Tb). The controller (16) calculates a response time of the fuel cell system based on the measured temperature, and controls the supply of hydrogen-containing gas to the fuel cell in response to the calculated response time.

Abstract: A terminal unit (TU) includes a battery terminal (2) mounted at the leading end of a wiring harness (4), and a holder (8) mounted on the wiring harness (4) at a position distanced from the battery terminal (2). A current sensor (12) is transported separately from the terminal unit (TU) to a connection site to a battery (B). The battery terminal (2) is introduced through the current sensor (12) and the current sensor (12) then is coupled with the holder (8) at the connection site. This operation is performed at a position distanced from the battery (B), and hence can be performed smoothly without being hindered.

Abstract: A rechargeable battery includes a housing comprising at least two cells that can be filled with an electrolyte. The rechargeable battery includes a cover and a degassing system having openings provided therein. The cover and the degassing system are arranged such that the openings provided in the cover and the degassing system are located above the cells of the rechargeable battery. A sealing plug is provided in each of the openings, the sealing plug having an upper part and a lower part having a splash basket. The upper part covers the openings on the outside of the cover and the lower part extends in the direction of the cells. The splash basket surrounds a cavity and has slots distributed over its circumference, the slots continuing as far as a free end of the splash basket.

Abstract: A small fuel cell (10) powers a portable electronic device (12) and contains a fuel reservoir (14) and a device (16) that measures the amount of liquid fuel (18) that is in the reservoir. The fuel cell operates on hydrogen that is obtained from a liquid hydrocarbon fuel, such as alcohol or other hydrocarbons. The liquid fuel is typically converted into hydrogen by a reforming process. The reservoir that is connected to the fuel cell has an indicia (19) that is readable by a human user of the portable electronic device, for measuring the amount of liquid hydrocarbon fuel that is present in the reservoir. Typically, the indicia consist of a sight glass, a capacitive element, a resistive element, a transparent portion of the reservoir, a float, or an acoustic transmitter coupled with an acoustic receiver.

Abstract: Disclosed is a fuel cell comprising a fuel cell body (stacked body) including a unit cell having an electromotive section in which an electrolyte membrane is sandwiched between a fuel electrode and an oxidant electrode, and a liquid fuel tank for storing a liquid fuel that is to be supplied to the fuel cell body and connected to the fuel cell body. The liquid fuel is introduced by the capillary action into the unit cell included in the fuel cell body and vaporized within the unit cell so as to be supplied to the fuel electrode, thereby generating an electric power. The liquid fuel tank is provided with a pressure adjusting mechanism for introducing a required amount of the liquid fuel from a liquid outlet port into the unit cell.

Abstract: The battery pack of the invention comprises an outer case, a battery main body disposed within the outer case, and a heat-sensitive current blocking element mounted on the outer surface of the battery main body. On the inner surface of the outer case is provided a press portion for pressing the heat-sensitive current blocking element against the outer surface of the battery main body. In this arrangement, even when the battery pack is given vibration or impact, the heat-sensitive current blocking element can be kept retained in close contact with the outer surface of the battery main body. Accordingly, the heat generated in the battery main body can be rapidly and surely transferred to the heat-sensitive current blocking element, making sure that thermal runaway of the battery is prevented.

Abstract: An indicator of battery charge is disclosed which is incorporated into a battery to allow persons possessing knowledge of remaining battery capacity to easily modify tactile and visual characteristics of said battery as an indication of remaining charge. Said characteristics are, but not limited to, coatings, attachments for removal and devices, which can be altered in form.

Abstract: A method of evaluating an electrochemical cell for a metallic contaminant-caused defect. The electrochemical cell is configured for use with an implantable medical device and includes an anode, a solid cathode and a liquid electrolyte. The method includes storing the cell at an elevated temperature following assembly for accelerating corrosion of possible metallic contaminants. A parameter of the cell related to cell voltage is then measured. An evaluation is made as to whether the cell is defective based upon this measured parameter.

Abstract: Deficiencies in the electrolyte level of the cells of NiCd battery can be detected by measuring the internal resistance of the cells. Initially, data is collected for a battery type and capacity, correlating measured internal resistance with the amount of water that must be added to bring the cell resistance to an acceptable value. Subsequently, cells of other batteries of the same type and capacity can be measured to determine how much water must be added and the levels quickly restored. The polarization value of the cells can be used lieu of the internal resistance in the same fashion.

Abstract: An end cap assembly for an electrochemical cell, for example an alkaline cell, is disclosed comprising an exposed terminal end cap of single piece construction having a convoluted surface, an electrically insulating member and a metal support disk between the insulating member and the terminal end cap. The end cap assembly is inserted into the open end of the cell housing after the cell contents have been supplied. A portion of the end cap surface is a flat annular step which improves contact between the end cap and the electrically conductive portion of a condition tester for the cell which may be integrated into the cell label. The annular step is advantageously located at about right angle to the cell's longitudinal axis. The surface step is integral with the end cap and preferably located at about the same level as the shoulder of the cell housing at the end of the cell containing the end cap. The end cap assembly as a whole provides a tight seal for the cell.

Abstract: Provided herein is a novel breath test for assessing hepatic function. The test involves administration of a labeled methionine or methionine metabolite to a subject and measurement of the expired label.

Abstract: A method of recovering and restoring the voltage in a zinc-air battery that has dropped below a first threshold. The method includes the steps of decoupling essentially all loads from the zinc-air battery and permitting the voltage to stabilize, sampling the voltage to determine if the voltage of the zinc-air battery is below a second predefined threshold, starting a timer and determining if the voltage has recovered to at least a third predefined threshold prior to the timing out of the timer, and periodically sampling the voltage to determine if the voltage has recovered to a voltage above a fourth predefined threshold for a sustained period of time, the periodic sampling being done if the zinc-air battery fell below the first predefined threshold but did not fall below the second predefined threshold, and upon determination that the voltage of the zinc-air battery has recovered to above the fourth predefined threshold, coupling the loads, previously decoupled from the battery, back to the battery.

Abstract: A capacity detection method for use with a secondary battery is provided which is capable of accurately detecting capacity by a voltage method by taking into consideration the polarization characteristics of a secondary battery, such as a lithium-ion secondary battery. When the capacity of a secondary battery is to be detected, this capacity detection method uses a voltage method in which the voltage of a secondary battery is measured and the capacity of the secondary battery is computed on the basis of the correlation between the voltage and the capacity of the secondary battery. A voltage and capacity correlation table of the secondary battery is prepared. The voltage of the secondary battery in the correlation table is adjusted by taking the polarization characteristics into consideration, and the capacity of the secondary battery is detected on the basis of the adjusted voltage of the secondary battery.

Abstract: A method for producing a battery tester label is disclosed. The method includes forming an inserted tester device and a base layer, which are combined together to form the battery tester label. The resulting tester label can be applied to a battery. Also disclosed are methods for producing a plurality of battery tester labels disposed on a common releasable liner. The resulting array can be stored for subsequent application to batteries, cut into relatively long strips for rolling and storage, or immediately applied to batteries.

Abstract: The present invention relates to a new method of constructing and interrogating electrochemical cells, especially those having lithium thionyl chloride (Li/SOCl.sub.2) chemistry, that permits rapid estimation of remaining discharge capacity. A preferred embodiment of the present invention employs cells with specially modified anode structures and a method for testing the state of charge and remaining life of these cells, as well as depassivating these cells, prior to their intended use or re-use. The test method can be performed using an inexpensive DC circuit and voltmeter at ambient conditions anytime prior to cell use or re-use.

Abstract: The invention pertains to linear electrochemical functional elements which consist of strip-shaped ion-exchange membranes (IEMs) and/or hydrogen-diffusion electrodes accessible at the ends which are enclosed on all sides in an insulating manner by a jacket of a solid material. The invention describes the structure, production and use of the functional elements in electrochemical measuring techniques.

Abstract: A battery electrolyte level indicator constructed for substitution of a battery cap on a multi-cell battery. The electrolyte level indicator has an outer housing construction in the shape of a cap to be screw mounted into the open upper end of the port leading into the battery cell. A probe extends from the housing or cap, into the battery electrolyte. A light indicator, such as a light emitting diode, is mounted on the exterior of the cap housing and will become automatically energized in a fail-safe condition if the electrolyte is at a sufficient level within the cell. However, if the level of the electrolytes should drop below the depth of the probe, then the indicator light will be deenergized, thereby immediately providing an advisory signal to the operator of an unsafe battery condition. The probe is constructed so as to operate as an anode in combination with a cathode of the battery.

Abstract: A modular, stackable battery pack and electronic accessory system which allows one or more batteries to simultaneously power one or more electronic accessories. The battery packs and accessories each have two opposing faces which are configured to releasable mate with each other and to provide electrical connection between the components. In some embodiments, the accessory is configured to be one of the terminal ends of the system, and thus has only one face with a releasable connector. The other face may be reserved for operation of the accessory. In other embodiments, the battery packs themselves may also comprise an electronic accessory. Accessories suitable in the practice of this invention include a cellular telephone, a PDA, a pager, a personal stereo (AM/FM radio or cassette, DAT or CD player), a calculator, an alarm clock, an electronic address book, a shaver, a solar powered battery pack recharger, a voice memo recorder, a tazer or a flashlight.

Abstract: The present invention relates to state of charge indicators for a battery. One aspect of the present invention utilizes expansion and contraction displacements of an electrode plate of a battery to gauge the state of charge in the battery. One embodiment of a battery of the present invention includes an anodic plate; a cathodic plate; an electrolyte in contact with the anodic and cathodic plates; plural terminals individually coupled with one of the anodic and cathodic plates; a separator intermediate the anodic and cathodic plates; an indicator configured to indicate an energy level of the battery responsive to movement of the separator; and a casing configured to house the anodic and cathodic plates, electrolyte, and separator.

Abstract: A method and apparatus for determining the instantaneous state-of-charge of a battery in which change in composition with discharge manifests itself as a change in optical absorption. In a lead-acid battery, the sensor comprises a fiber optic system with an absorption cell or, alternatively, an optical fiber woven into an absorbed-glass-mat battery. In a lithium-ion battery, the sensor comprises fiber optics for introducing light into the anode to monitor absorption when lithium ions are introduced.

Abstract: A light transparent moisture barrier useful for preventing moisture from destroying the effectiveness of a moisture sensitive cell condition tester on an electrochemical cell, comprises a plurality of very thin layers of amorphous silicon nitride and a hydrophobic fluorocarbon polymer on a flexible, polymeric substrate. The layers are formed on the substrate by a deposition process such as sputtering. The thickness of any individual layer is less than one micron.

Abstract: At step S21, a residual amount judging section of abattery residual amount display circuit measures a battery voltage. If a mode transition is detected at step S22, the process returns to step S21 without executing the subsequent steps. If it is judged at step S23 that the operation mode is a reception-waiting mode, the process goes to step S24, where the battery amount judging section judges a battery residual amount by comparing the detected battery voltage with threshold values. If the operation mode is judged to be a transmission mode, the battery residual amount judging section determines a voltage drop during a transmission at step S25, and converts the voltage drop into a battery voltage of a reception waiting mode at step S26 by subtracting the voltage drop from a batter voltage obtained in a reception waiting mode immediately before the mode transition.

Abstract: In a method and apparatus for measuring battery state-of-charge, the total available capacity is calculated using natural logarithms. The application of natural logarithm instead of using Peukert's Equation simplifies the method and provides higher accuracy.

Abstract: A display device of a storage battery for optically displaying a condition of an electrolytic solution stored in a casing of the storage battery comprises a pillar member having a transparent body having one end and other opposite end, the one end of the pillar member being engaged at an upper surface of the casing in a usable state so that the other opposite end thereof projects into the casing. An inclined end surface of the opposite end side thereof is inclined to a side surface of the pillar member at a predetermined angle so that an incident light transmitting from the one end side thereof permeates through the inclined end surface or is reflected thereby according to the condition of the electrolytic solution which is in contact with the inclined end surface.

Abstract: An apparatus for displaying the charging of the battery of an electric vehicle has a charging connector mounted on an outer panel of a vehicle body of the electric vehicle, a lid openably mounted on the panel in covering relation to the charging connector and a cavity defined in the outer panel, and a display panel disposed in the cavity for displaying a period of time required until the battery is fully charged and/or a charged capacity of the battery. The driver of the electric vehicle can easily recognize the remaining time required until the battery is fully charged and a percentage of the fully charged capacity of the battery to which the battery is presently charged, from outside of the electric vehicle. The driver is not required to confirm the state of charge of the battery with an indicator on a battery charger or within the passenger's compartment of the electric vehicle, but can easily confirm the state of charge of the battery from outside of the electric vehicle.

Abstract: A battery and circuitry for monitoring state of charge of the battery are housed in a single housing. A display may be provided for displaying an indication of the state of charge, and a communication circuit may be provided for communicating electrical signals representing the state of charge to the exterior of the housing. Preferably, the battery module additionally includes a switch device for connecting the battery to terminals external to the housing and control circuitry responsive to the monitoring circuitry for causing the battery to be connected to and disconnected from the terminals. The control circuitry operates in accordance with thresholds to prevent deep discharge and overcharge.

Abstract: The dangers of excessive battery current and battery heating are effectively prevented by maintaining a heat sensitive cut-off device in the cut-off state as long as an over-current situation exists. An inside case positioned in the enclosed space between the batteries and the outside shell houses both the cut-off device and a parallel connected heating resistor. Double insulation allows the heating resistor to efficiently transfer Joule heat to the adjacent cut-off device. Effective use of space and heat transfer properties also reduces post-cut-off battery current and results in no battery pack volume increase.

Abstract: A removable battery pack for powering a pen-based or portable computer system in which the battery pack blocks its terminals when inserted into an unknown system. The known system includes a power supply microcontroller which passes battery charge data back and forth between a memory located in the battery pack and the power supply microcontroller. A battery microcontroller, located in the battery pack, eavesdrops drops on the communication between the power supply microcontroller and the memory, and when it validates a known signature of this communication, the battery microcontroller then enables the terminals of the battery pack. A trickle discharge current flows from the battery pack whenever the battery pack is out of the known system to allow the power supply microcontroller to power up in the case of a dead auxiliary battery.

Abstract: An improved state-of-charge indicator for a battery wherein the counter cuit of the battery state-of-charge indicator includes a means for both resetting and fine-tuning the counter circuit. The current flowing from the monitored battery is passed through a sensing resistor. The voltage across the resistor is amplified and integrated over time and the result of the integration is stored in a capacitor discharged by a switch whenever a threshold voltage is achieved. The cycle is repeated each time coulomb of capacity is removed from the battery. The counter circuit counts the charge/discharge cycles of the capacitor resulting in a count representative of the amount of energy dissipated and therefore indirectly of the amount of energy remaining in the battery system. In this improvement, both a resetting means and a fine-tuning means are included for the counter circuit when the battery is being recharged.

Abstract: A light transparent moisture barrier useful for preventing moisture from destroying the effectiveness of a moisture sensitive cell condition tester on an electrochemical cell comprises a plurality of very thin, alternating layers of an inorganic material and an organic material on a flexible, polymeric substrate. The layers are not laminated, but are formed on the substrate by a deposition or coating process and the thickness of any layer is less than 5 microns. The organic material is a hydrophobic polymer and the inorganic material is a metal oxide, nitride, a glass or silicon.

Abstract: A battery encased with a label containing an integral test circuit device that is thermally insulated from the battery by an expanded material and is activated by depressing a selected area of the label whereupon a thermally sensitive material associated with the test circuit displays whether the battery has capacity. A method for producing the test circuit device is also disclosed.

Abstract: A condition indicator assembly (tester) for determining the condition of a main cell, e.g. a battery, is disclosed. The condition indicator assembly may comprise an electrochemical indicator cell connected in series to a auxiliary cell. The indicator cell and auxiliary cell each have an anode, cathode and electromotive force (e.m.f.) of its own. The condition indicator assembly may be permanently connected in parallel to the terminals of a main cell being tested. The condition indicator assembly is thin enough that it may be interated into a label for the main cell. As the main cell discharges, the indicator cell anode clears proportionally to the discharge of one of the electrodes of the main cell to provide a continuous visually discernible indication of the state of charge of the main cell.

Abstract: A battery strength indicating and switch means on a battery which is coupled across the terminals of the battery and which is provided with an indicating means to indicate the strength of the battery and in addition, the battery strength indicating means is also provided with an in-line switch which can easily be depressed to complete the circuit so as to place the indicator means across the terminals of the cell and display the charge of the battery.