Abstract: A car power source apparatus is provided with a battery having a plurality of battery modules connected in series on positive and negative sides of a midpoint reference node, and a voltage detection circuit that detects the voltage of one or a plurality of battery modules with respect to the midpoint reference node of the battery. The battery midpoint reference node of the power source apparatus is connected to the voltage detection circuit via a plurality of reference connection lines. Further, one or a plurality of conduction detection circuits connect to the reference connection lines, supply a voltage to each reference connection line, and detect current. The connection status of each reference connection line to the midpoint reference node is determined by this conduction detection circuit.

Abstract: A voltage equalizer for battery elements for equalizing terminal voltages of a plurality of battery elements comprises an equalization processing circuit. The equalization processing circuit includes a transformer having basic windings. The basic windings comprise a plurality of primary windings corresponding to the plurality of battery elements and one or more secondary windings, a plurality of switching elements corresponding to the battery elements, a plurality of primary diodes corresponding to the battery elements, and one or more secondary diodes corresponding to the secondary windings. In the voltage equalizer, primary series circuits for carrying current from the battery elements via the corresponding primary diodes to the primary windings and secondary series circuits for carrying current from the secondary windings via the secondary diodes to the battery elements are formed.

Abstract: A power supply apparatus has a battery that is composed of a plurality of battery modules connected in series, a voltage detector that detects the relative voltages at the individual nodes between the battery modules with respect to a predetermined reference node, an erroneous detection checker that checks whether each of the detected relative voltages is an erroneously detected voltage and a normally detected voltage, and a calculation circuit that calculates the voltages of the individual battery modules based on those relative voltages that are judged to be normally detected voltages.

Abstract: A small and low-cost capacity equalizing apparatus for equalizing the capacities of battery blocks constituting an assembled battery, each battery block comprising one or multiple secondary batteries and the battery blocks being connected in series. The capacity equalizing apparatus in accordance with the present invention comprises an assembled battery, n discharge devices and a controller. The assembled battery has a configuration wherein n battery blocks (n is a positive integer of 2 or more), each comprising one or multiple secondary batteries, are connected in series. The n discharge devices, each connected across the positive and negative electrode terminals of each of the n battery blocks, discharge the secondary batteries inside the respective battery blocks. The controller has a first control section to which the battery blocks are electrically connected and a second control section electrically insulated from the first control section.

Abstract: A system is provided for balancing state of charge among plural series connected electrical energy storage units that includes a power converter that selectively couples to an individual storage unit of the a string of electrical energy storage units and bidirectionally transfers energy between the individual storage unit and the string of storage units.

Abstract: A system and method for cell balancing with smart low-voltage control circuit. The cell balancing system comprises a plurality of battery cells, an external bypass path for each cell, an internal bypass path for each cell, an input terminal receiving an enable signal for each cell, an input terminal receiving a selection signal, and a cell balancing unit for generating a configuration signal to conduct the external bypass path or internal bypass path. The enable signal is configured to enable a bypass current of each cell, and the selection signal is configured to select the external bypass path or internal bypass path. The cell balancing unit is employed to receive signals from input terminals, and generate a configuration signal to control the conductance of external bypass paths or internal bypass paths.

Abstract: A battery management system and a driving method thereof to manage a battery including a plurality of cells. The battery management system includes a sensing unit, an MCU, and a cell balancing unit. The sensing unit measures cell voltages of the plurality of cells. The MCU detects cells requiring cell balancing according to the plurality of measured cell voltages and generates a plurality of cell voltage signals to control the cell balancing of the detected cells. The cell balancing unit balances the cells according to the plurality of cell voltage signals, and the number of the cell voltage signals is fewer than the number of cells. The cell balancing unit generates a plurality of cell balancing signals corresponding to each of the plurality of cell voltage signals, and at least one of the cell voltage signals balances at least two of cells in the battery.

Abstract: For estimation of a critical state of a performance under a working condition of a secondary cell, in consideration of an internal resistance of the cell, a variable data provider provides variable data on the performance, including a first data on a variant of the performance, a second data on a current of the cell, and an estimated third data on a dynamic characteristic of the internal resistance, a specified data provider provides specified data on the cell, including a fourth data on a permissible range of the variant under the prescribed working condition, and exact data on the dynamic characteristic, and a critical state estimator processes the variable and specified data for estimation of the critical state, and has an internal resistance setter to process the second and third data to set exact data as a function of second data defining the dynamic characteristic, and an estimating element to process the first, fourth, and exact data to estimate the critical state.

Abstract: A battery backup system includes a control device including a power sensing device, a discharge circuit, a charging circuit, and a plurality of battery packs. A lower threshold is established representative of a minimum acceptable effective energy capacity. Each battery pack is recharged if its effective energy capacity falls below the lower threshold. Additionally, an upper threshold is established representative of the minimum acceptable effective energy capacity plus a performance margin. In a two battery-pack system, if both battery packs fall below the upper threshold, the battery with the least effective energy capacity is discharged to the minimum acceptable effective energy capacity and then recharged to the battery pack's maximum energy capacity. In this way, both battery packs are prevented from approaching the minimum acceptable effective energy capacity at the same time. This reduces the size or number of battery packs and reduces their associated cost and volume.

Abstract: In a method of charging batteries, a microcontroller and a series divider resistor are used to control the level of a charge current source supplied from a power supply, so that a plurality of serially connected batteries in a battery pack could be best charged. The microcontroller detects a voltage value of the battery pack via the series divider resistor. When all the batteries in the battery pack have been charged in a first charging cycle, the microcontroller controls the power supply to lower the output charge current and to charge the batteries in a second charging cycle, until the charge has been cycled a preset number of times. As a result, all the serially connected batteries in the battery pack are best charged.

Abstract: A charging circuit includes a battery pack having a plurality of serially connected batteries and being connected to a power supply; a changeover switch being serially connected to and between any two adjacent batteries; and a precision voltage detector being parallelly connected to each of the batteries for independently detecting a voltage of the connected battery and sending out a detected result to a charging control circuit for controlling the ON/OFF of the changeover switch corresponding to the battery. When a battery is detected by a corresponding precision voltage detector as having been fully charged, the corresponding charging control circuit sets the changeover switch corresponding to the battery to OFF to stop charging the battery. The remaining batteries that are subsequently fully charged are disconnected from the power source one by one until all the batteries in the battery pack have been fully charged. Thus, all the batteries are balance-charged.

Abstract: A method of charging an electrochemical generator having a plurality of electrochemical cells. The method includes the step of charging the plurality of electrochemical cells such that the total voltage of the generator reaches a predetermined voltage level, followed by the steps of selecting a particular electrochemical cell and charging the particular electrochemical cell to its respective maximum voltage, such that the cathode(s) of the particular electrochemical cell is(are) restored to a fully-charged state. Once it has been restored to its fully-charged state, the particular electrochemical cell is allowed to discharge itself down to a nominal voltage. Each of the plurality of electrochemical cells of the generator is selected and charged to its respective maximum voltage in turn, according to a predetermined selection sequence.

Abstract: A NiH/NiCd (nickel hydrogen/nickel cadmium) battery charger with the function of emergency power supply unit having a main body with a charging chamber and a charging circuit positioned within the main body to allow an electric connection to the charging chamber and the power input interface. This charging control circuit is controlled by an electrical switch which divides the charging chamber into two or more parts. When the power input interface is connected, the electrical switch shuts off automatically to make the batteries in the charging chamber to be charged in groups. This is the function of charger. When the power input interface is switched off, the batteries in different circuit are joined in series to supply power as an emergency power supply unit. Therefore, with the design principle of “separate charging and common sharing”, it can protect the rechargeable batteries and provide power in lacking of power supply unit outdoors.

Abstract: When a control section (39) turns on a switch (31, 33, 35), a capacitor (37) is connected to a secondary battery (B1) in parallel. Accordingly, voltage between both ends of each capacitor (37, 38) reaches voltage between both polarities of each secondary battery (B1, B2). Thereafter, when the control section (39) turns off the switch (31, 33, 35) and turns on a switch (32, 34, 36), each capacitor (37, 38) is connected to the secondary battery (B2, B3) in parallel. The capacitor (37, 38) is charged/discharged to balance voltage between both polarities of the secondary battery (B1 to B3).

Abstract: Providing a charge condition adjusting apparatus, which can shorten a time for equalization of each charge in unit cells, a low-voltage CPU selects each smallest unit cell in the each cell block, which has each smallest voltage between the both electrodes, from among plural unit cells structuring the cell blocks. The low-voltage CPU controls ON/OFF of a block-discharging switch to connect the both electrodes of each cell block and each block-discharging resistor for discharging the each cell block until the each voltage between the both electrodes of the selected smallest unit cell reaches the target voltage. Successively, the low-voltage CPU controls ON/OFF of a selecting switches and a cell-discharging switch to connect the both electrodes of each unit cell and each cell-discharging resistor to discharge the each unit cell until the each voltage between the both electrodes of the unit cells reaches the target voltage.

Abstract: A method for balancing cells or groups of cells connected in parallel and in series for a battery pack by providing a continuously balanced state of charge while in a discharge phase, a charge phase, a quiescent phase, a storage phase, or combinations of these phases.

Abstract: A battery pack control module for balancing a plurality of cells or groups of cells connected in series includes a controller assembly, a disconnect circuit, a pack sensing circuit, a balancing circuit, and computer instructions for instructing the controller assembly to control the disconnect circuit and the balancing circuit. The disconnect circuit engages the controller assembly and a plurality of cells or groups of cells connected in series. The pack sensing circuit connects to the controller assembly and the plurality of cells or groups of cells connected in series. The balancing circuit connects between the plurality of cells or groups of cells connected in series, and engages the controller assembly. The plurality of cells or groups of cells connected in series is balanced when the battery pack control module operates in a charging phase, a discharging phase, a quiescent phase, or a storage phase.

Abstract: A balancing circuit for voltages of a series connection of capacitors, particularly for intermediate circuit capacitors (3) of an inverter, there being at least two intermediate circuit capacitors connected in series over intermediate circuit voltage. The balancing circuit comprises capacitor-specific freely oscillating inverters (4), the input poles of which are connected in parallel with the capacitor corresponding to the inverter and the output poles of which are connected in parallel to provide a voltage source (Va).

Abstract: A voltage balancer device has a plurality of discharge paths. Each pair of the discharge paths correspond to each secondary battery unit. Each of a pair of the discharge paths has a resistance of a different value. Discharging the voltage of each secondary battery unit is at first performed through the discharge path of a smaller resistance value. The voltage balancer device switches the currently used discharge path to another discharge path having a large resistance value at the time the voltage of the secondary battery unit nearly equal a desired voltage.

Abstract: Methods and apparatus are provided for charging a high-voltage battery of a hybrid electric vehicle. The high-voltage battery charging apparatus comprises a battery charger configured to provide electrical energy, a battery module configured to store the electrical energy provided by the battery charger, and a high-voltage bus coupled to the battery charger and the battery module, which is configured to transmit the electrical energy from the battery charger and battery module to the electrical system of the hybrid electric vehicle. In addition, the high-voltage battery charging apparatus comprises a bus contactor interposed between the high-voltage bus and the battery charger, which is bus contactor configured to provide a first substantial electrical isolation between the battery charger and the high-voltage bus during a charging period of the battery module.

Abstract: A method for extending the power duration of lithium ion cells or groups of lithium ion cells connected in parallel and in series by providing a continuously balanced state of charge while in a discharge phase, a charge phase, a quiescent phase, a storage phase, or combinations of these phases.

Abstract: When an output voltage of a secondary battery cell E1 is obtained, only SW1 and SW2 are turned on. As a result, a capacitor C1 is charged by a secondary battery cell E1. With a delay of a time period ÄT, SW1 and SW2 are turned off. SW4 and SW5 are turned on. As a result, electric charges of the capacitor C1 are moved to a capacitor C2. Those operations are repeated until the potential of the capacitor C2 becomes almost equal to the output voltage of the secondary battery cell E1. When the potential of the capacitor C2 becomes almost equal to the output voltage of the capacitor C2, the potential of the capacitor C2 is detected by the voltage detector 11. A first terminal of the capacitor C2 is connected to a ground potential. As a result, the voltage of the secondary battery cell E1 can be stably detected. When the secondary battery cell E2 is detected, only SW5 is turned on. As a result, the capacitor C2 is charged by the secondary battery cell E2.

Abstract: According to an example embodiment, an arrangement charges equipment batteries, for example, while the equipment is being towed by a towing vehicle. In this example application, the towing vehicle has a primary battery and a rearward-located hitch for towing a trailer that carries the equipment batteries. The arrangement includes a charging circuit that automatically alternates a power connection from the primary battery to each of the equipment batteries, one battery at a time.

Abstract: A traveling apparatus and a method for controlling thereof performs efficient charging with regenerative electrical power. An angle ?0 of a table (not illustrated) is detected by a gyroscopic sensor and an acceleration sensor to be supplied to a central control unit. Then, positional command signals Pref1(t) and Pref2(t) formed are supplied to motor control units which perform control of driving left and right motors respectively. Further, rotational positions ?m1 and ?m2 of the motors are respectively detected in rotary encoders, those det signals are fed back to the motor control units, and control is performed so as to comply with the positional command signals Pref1(t) and Pref2(t) formed in the central control unit.

Abstract: A safety device for lithium ion cells or groups of lithium ion cells connected in parallel and in series by providing a continuously balanced state of charge while in a discharge phase, a charge phase, a quiescent phase, a storage phase, or combinations of these phases.

Abstract: A multi-battery automatic charging circuit with individual regulator is further provided with one secondary or more than one output interface to convert an AC source via a rectifier into a DC charging source, thus to supply power to an external rechargeable device or a DC load of different voltage through a tap of the circuit specific voltage; or alternatively, a primary battery, or a rechargeable battery provided with storage capacity, or any other rechargeable device generally available in the market is placed in the battery holder provided otherwise for the placement of rechargeable batteries to charge the external rechargeable device or to supply power to a DC load.

Abstract: A contactless power transmitting device is provided including a power transmitting device functioning as a charger, a power transmitting-receiving sharing device functioning as a charger and including a secondary battery, and a power receiving device including a secondary battery. The power transmitting-receiving sharing device is used as a power supply for portable computers. The power receiving device is used as a power supply for cellular phones. The power transmitting device forms a contactless power transmitting device respectively by electromagnetically coupling to either the power transmitting-receiving sharing device or the power receiving device to charge the secondary battery or the secondary battery. The power transmitting-receiving sharing device forms the contactless power transmitting device by electromagnetically coupling to the power receiving device. In this case, the power transmitting-receiving sharing device charges the secondary battery included in the power receiving device.

Abstract: The present invention relates to a series charger with separate detection of batteries which includes a charging control device for converting the inputted AC power into DC power so as to charging four batteries in series connection. The charging control device further provides a reference voltage source to a control IC which is connected with a current detector for measuring the current value of the batteries. Each of the series-connected batteries is parallel-connected with a switch element. A one-way diode is interposed between the positive end of the batteries and each of the switch elements. Besides, the control IC provides ??V to the positive terminal of the respective charging circuit of the batteries for detecting the end-point voltage thereof. When each of the batteries is fully charged, the respective switch element is switched in a close circuit so that the charging current continues to flow downward for further charging operation.

Abstract: An electric circuit for equalizing voltages between serially arranged cells. The circuit is operable to generate AC voltages at amplitudes dependent on the DC voltages of the received cells. The AC voltages are all connected to an inductive coupling circuit. The inductive coupling allows higher-voltage cells to induce a recharging current flow in lower voltage cells and so equalize the cell voltages. The circuit also operates to ensure that cell voltages are maintained in equilibrium during charging or discharging of received cells, irrespective of the individual charging and discharging characteristics of the cells. The circuit thus prevents individual cells in a battery from being over-charged or over-discharged and allows more efficient use of the full capacity of a battery without risking damage to the individual cells. The cell equalizing circuit is thus especially useful for rechargeable cells, such as lithium-ion cells, which are sensitive to damage by over-charging and over-discharging.

Abstract: A decentralized management model enables a plurality of interconnected modules to be managed and controlled as an integrated unit without requiring any one of the interconnected modules to operate as a fully centralized manager. One of the interconnected modules is configured to operate as a base module, which coordinates certain network management operations among the interconnected modules. Each of the interconnected modules is capable of sending and receiving management and control information. Each of the interconnected modules maintains a segmented management database containing network management parameters that are specific to the particular module, and also maintains a shadowed management database containing network management parameters that are common to all of the interconnected modules in the stack.

Abstract: An integrated battery monitoring device includes a pair of input leads for coupling across the terminals of a battery cell to be monitored and a sensor for sensing a desired battery cell parameter. A self-contained power supply has the voltage across the battery cell terminals as an input thereto, the self-contained power supply being configured for providing power to the sensor. A pair of output leads communicates data generated by the sensor.

Abstract: The present invention is directed to a carrying case with an integrated power supply system for providing power to multiple electronic devices from a single power source. In addition to allowing quick access and storage of various electronic devices, the carrying case also allows the individual electronic devices to be easily connected to the power source and eliminates the need to carry multiple charging cords. In certain embodiments, the power supply system further includes an additional battery or other power source, which increases the runtime of connected electronic devices and reduces the need to carry additional individual batteries for the individual devices. With different connectors on the input to the power system, different AC or DC power sources may be utilized. Different connectors can also be used to provide power to different electronic devices.

Abstract: A battery pack for a battery-powered vehicle is provided in accordance with the present invention. The battery pack for the battery-powered vehicle comprises battery modules coupled in series. The battery modules are configured to provide power to the battery-powered vehicle and each of the battery modules has a state-of-charge. The battery pack also comprises battery control modules (BCMs) that are coupled to the battery modules. Each of the battery modules is coupled to one of the BCMs and each of BCMs is configured to monitor a battery module parameter. Furthermore, the battery pack comprises a battery control interface module (BCIM) coupled to each of the BCMs. The BCIM is configured to receive the battery module parameter from each of the BCMs and independently adjust the state-of-charge of each of the battery modules based on the battery module parameter.

Abstract: A device and method for equalizing the charge among a plurality of batteries redundantly driving a motor. The batteries are coupled to the motor through isolated windings and to each other through the drive shaft. The device senses the charge of the batteries and then controls the current from each of the batteries to its respective winding to equalize the charge. Related methods are provided to maximize the speed limit of a balancing transporter.

Abstract: A bandgap reference circuit and method of using the same are provided. The bandgap reference circuit may provide start-up requirements at substantially any voltage and at substantially any temperature. The circuit comprises an op amp (two stages of transistors) and a network of resistors and bipolar diodes. When an artificial offset of about ?5 mV is introduced to the op amp, the op amp output will be high as soon as the power supply exceeds the transistors' threshold voltages. The op amp output supplies the resistor and diode network and brings the op amp inputs within desired regulation voltages.

Abstract: A system for equalizing the voltages across first and second batteries coupled in series at a common terminal comprising a capacitive storage element, first and second inductive storage elements, first and second switch circuits, and a control unit. The capacitive storage element is coupled to first and second nodes. The first inductive storage element is coupled between the first node and the first battery. The second inductive storage element is coupled between the second node and the second battery. The first switch circuit is coupled between the first node and the common terminal. The second switch circuit is coupled between the second node and the common terminal. The control circuit operates the first and second switch circuits to control current flow to the first and second batteries.

Abstract: A battery charger includes line-level input rectification, a high-frequency oscillator-controlled chopper circuit, multiple transformers operating in parallel, and controlled output rectification. Use of line-level input rectification reorders the elements of the battery charger compared to previous designs. A chopper frequency several orders of magnitude higher than that of the AC power mains is used. The use of multiple, parallel-wired transformers for voltage and current transformation eases constraints on the physical geometry of a manufactured battery charger product by permitting individual transformers, each smaller than a comparable single transformer, to be employed. Controlled output rectifiers permit power levels to be regulated dynamically.

Abstract: A charge balancing circuit is configured to provide charge balancing for a bank of series connected charge storage devices. One embodiment of the charge balancing circuit comprises a voltage divider, an amplifier, and a negative feedback resistor connected between every two capacitors. The circuit is configured to monitor the voltage in each of the capacitors and, if the voltage in one of the capacitors is higher than the other, the circuit transfers energy from the higher charged capacitor to the lower charged capacitor until the capacitors are balanced. A current limiting resistor can be included for limiting the output current of the amplifier to a safe value and for providing feedback information regarding the health of the capacitor. An additional gain stage can also be included for increasing the output current of the amplifier for banks of large charge storage devices. The circuit can be used in bi-polar applications.

Abstract: A battery charging system includes two or more rechargeable batteries, a charging power supply charging the batteries with an external electrical power, a charging power sensing part sensing at least one of a voltage and a current of a charging power supplied from the charging power supply to the batteries, and a charging control part controlling the charging power supply to supply an idle power created during charging one battery, to another battery according to a sensed result of the charging power sensing part. With this configuration, a charging time of the two or more batteries is reduced, and the electrical power is efficiently used when the two or more batteries are charged.

Abstract: A method and a device for implementing a charge-state equalization among the cells of a vehicle battery are described. This charge-state equalization is carried out under the control of a vehicle-side control unit that includes the vehicle management and the vehicle control device. The charging currents required for the charge-state equalization are provided by a secondary battery of the vehicle and conveyed from there to the vehicle battery when the need for a charge-state equalization is detected.

Abstract: A rechargeable electrochemical cell system is provided. The system includes a plurality of cells, wherein each cell is comprised of a first electrode, a second electrode, and a third electrode electrically isolated from the second electrode. The cell system may be discharged upon application of a load across a discharge circuit, which is formed from the first electrodes and the second electrodes. The cell may be recharged upon application of a voltage across a recharging circuit, which is formed of at least one of the first electrodes and at least one of the third electrodes.

Abstract: An apparatus for use with a charge control system for affecting current draw from a charging unit coupled at an input locus of the charge control system for charging a battery unit includes a current sink switchingly coupled with the input locus for selectively contributing a predetermined current draw at the input locus. A method for selectively establishing a predetermined current draw from a charging unit coupled at an input locus with a charge control unit for charging a battery unit includes the steps of: (a) providing a current sink switchingly coupled with the input locus; (b) sensing at least one predetermined condition in the battery unit; and (c) switchingly engaging the current sink when the at least one predetermined condition satisfies at least one predetermined criteria.

Abstract: A charge balancing circuit is disclosed that is configured to provide charge balancing for a bank of series connected charge storage devices such as capacitors. One embodiment of the charge balancing circuit comprises a voltage divider, an operational amplifier, and a negative feedback resistor connected between every two capacitors. The circuit is configured to monitor the voltage in each of the capacitors and, if the voltage in one of the capacitors is higher than the other, the circuit transfers energy from the higher charged capacitor to the lower charged capacitor until the capacitors are balanced. A current limiting resistor can be included for limiting the output current of the operational amplifier to a safe value and for providing feedback information regarding the health of the capacitor. An additional gain stage can also be included for increasing the output current of the operational amplifier for banks of large charge storage devices such as capacitors.

Abstract: A method and system for equalizing the voltage of batteries in a battery string to a desired voltage. An equal string current is drawn from the batteries of the battery string and redistributed as a plurality of secondary currents to each battery depending upon the comparative voltage of the individual batteries. A larger secondary current is provided to batteries having a low voltage and a smaller secondary current is provided to batteries having a high voltage. A transformer is provided electrically connected to the battery string having an input winding connected to the battery string such that it receives an equal string current from each battery. The transformer has a plurality of output windings having an equal turn ratio, each output winding in parallel with a battery of the battery string, to provide a secondary charging current to a battery in the battery string.

Abstract: A charging circuit charging predetermined first and second batteries includes: a circuit configuration by which a second charging current charging the second battery is obtained by subtracting a first charging current charging the first battery from a current supplied by a power source; and a current setting part that sets the second charging current smaller than the first charging current at least at the beginning of charging.

Abstract: The present invention relates to a series charger with separate detection of batteries which includes a charging control device for converting the inputted AC power into DC power so as to charging four batteries in series connection. The charging control device further provides a reference voltage source to a control IC which is connected with a current detector for measuring the current value of the batteries. Each of the series-connected batteries is parallel-connected with a switch element. A one-way diode is interposed between the positive end of the batteries and each of the switch elements. Besides, the control IC provides −&Dgr;V to the positive terminal of the respective charging circuit of the batteries for detecting the end-point voltage thereof. When each of the batteries is fully charged, the respective switch element is switched in a close circuit so that the charging current continues to flow downward for further charging operation.

Abstract: A multi-battery automatic charging circuit with individual regulator is further provided with one secondary or more than one output interface to convert an AC source via a rectifier into a DC charging source, thus to supply power to an external rechargeable device or a DC load of different voltage through a tap of the circuit specific voltage; or alternatively, a primary battery, or a rechargeable battery provided with storage capacity, or any other rechargeable device generally available in the market is placed in the battery holder provided otherwise for the placement of rechargeable batteries to charge the external rechargeable device or to supply power to a DC load.

Abstract: A battery cell balancing method and apparatus. A simple and inexpensive method and apparatus to balance the cells within a battery configuration where at least some of the cells are arranged in series or a combination of series and parallel. One embodiment balances the cells proportionally to the level of imbalance between the cells. This embodiment is adaptable to more than two cells in series. Another embodiment balances the cells with a constant current. This embodiment will more quickly balance the cells because of the constant current. Components are selected in specific positions to reduce the current draw of the circuit and the effect on the system. The invention injects current into or withdraws current from a position between series cells to be balanced based on whether the voltage is higher or lower than the fractional voltage needed for the cells to be in balance.

Abstract: A method for controlling voltage levels among cells while charging a battery array to a target voltage uses cell balancing modes employing respective charging currents. The method includes the steps of: (a) In no particular order: (1) establishing a parametric criterion for identifying each balancing mode; (2) identifying a performance parameter associated with selected cells for each balancing mode; and (3) establishing an exit criterion for each balancing mode; (b) ascertaining the onset of charging; (c) identifying the extant balancing mode; (d) employing the charging current for the extant balancing mode for charging; (e) for selected cells: (1) obtaining an extant parameter associated with the cell; (2) comparing each extant parameter with the exit criterion; and (3) repeating steps (e)(1) through (e)(2) until the extant parameter satisfies the exit criterion; (f) terminating the extant balancing mode; (g) repeating steps (c) through (f) until target voltage is achieved; (h) terminating charging.

Abstract: An electric circuit for equalizing voltages between serially arranged cells. The circuit is operable to generate AC voltages at amplitudes dependent on the DC voltages of the received cells. The AC voltages are all connected to an inductive coupling circuit. The inductive coupling allows higher-voltage cells to induce a recharging current flow in lower voltage cells and so equalize the cell voltages. The circuit also operates to ensure that cell voltages are maintained in equilibrium during charging or discharging of received cells, irrespective of the individual charging and discharging characteristics of the cells. The circuit thus prevents individual cells in a battery from being over-charged or over-discharged and allows more efficient use of the full capacity of a battery without risking damage to the individual cells. The cell equalizing circuit is thus especially useful for rechargeable cells, such as lithium-ion cells, which are sensitive to damage by over-charging and over-discharging.