Abstract: A multiple cell battery charger configured in a parallel topology provides constant current charging. The multiple cell battery charger requires fewer active components than known serial battery chargers, while at the same time preventing a thermal runaway condition. The multiple cell battery charger in accordance with the present invention is a constant voltage constant current battery charger that includes a regulator for providing a regulated source of direct current (DC) voltage to the battery cells to be charged. The battery charger also includes a pair of battery terminals coupled in series with a switching device, such as a field effect transistor (FET) and optionally a battery cell charging current sensing element, forming a charging circuit. In a charging mode, the serially connected FET conducts, thus enabling the battery cell to be charged. The FETs are controlled by a microprocessor that monitors the battery cell voltage and cell charging current and optionally the cell temperature.

Abstract: A method to detect the presence of battery protection circuits in any battery powered product. The major advantage of the method is to make the battery voltage very smooth during the charging process. The proposed circuit can give a good prediction of protection switching turn on time. This can provide the battery powered system work smoothly by avoiding any battery voltage discontinuity. The proposed invention addresses the issue of deep discharge and provides a solution through a discharge test procedure.

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: A drive state detection circuit is disclosed that detects a drive state of plural parts driven by alternating currents.

Abstract: A fuel cell system determines each of a battery charging current error, a battery voltage error, and a stack current error. The fuel cell system regulates current through a series pass element in response to a greater of the determined errors. Thus, the fuel cell system operates in three modes: battery voltage limiting mode, stack current limiting mode and battery charging current limiting mode. Additionally, there can be a fourth “saturation” mode where the stack voltage VS drops below the battery voltage VB as the load pulls even more current. Individual fuel cell systems can be combined in series and/or parallel to produce a combined fuel cell system having a desired output voltage and current.

Abstract: A method and apparatus of the present invention are designed to equalize cell-to-cell imbalances in a multi-cell lithium battery system. A time-to-balance parameter is calculated for each cell at the beginning of charge, and balancing occurs for each cell having a positive time-to-balance at the beginning of charge. Alternatively, the time-to-balance parameter is calculated during operation of the battery system and equalization of the cells occur in-sit based on the time-to-balance values.

Abstract: An apparatus and method for recharging a rechargeable lead acid battery. The apparatus supplies an overcharge current to the battery during and before completion of recharging of the battery to ameliorate stratification of the battery.

Abstract: A lithium ion battery particularly configured to be able to discharge to a very low voltage, e.g. zero volts, without causing permanent damage to the battery. More particularly, the battery is configured to define a Zero Volt Crossing Potential (ZCP) which is lower than a Damage Potential Threshold (DPT). A method for using a battery capable of tolerating discharge to zero volts is also disclosed.

Abstract: A battery charging device both for charging a battery and for actuating a car engine includes a switch power supply circuit, a first, second, and third control circuit, and two control switches. While actuating the car engine, the battery charging device further employs a transient large current stage connected to the car engine. Users are capable of manually selecting the amount of the charging current for the battery and manually selecting different types of batteries to be charged. The battery is charged in the conductive time periods, and the voltage of the battery will be detected at the end of every conductive time period for determining entering next conductive time period or not. The battery charging device charges the battery with a constant current or with a smaller current under a constant voltage until the battery is fully charged.

Abstract: A charge/discharge protection circuit prevents a charge control FET from being overheated or ignited so as to improve safety by preventing an oscillating operation of the charge control FET, which is connected to a charge path of a secondary battery in series so as to cut off a charge current. A discharge control FET is connected to the charge path in series so as to cut off a discharge current from the secondary battery. A latch circuit latches an overcharge detection signal output from an overcharge detection circuit and outputs a signal so as to control the charge control FET. A delay circuit delays the discharge over-current detection signal and supplies the delayed discharge over-current detection signal to the discharge control FET. A reset circuit resets the latch circuit so as to turn on the charge control FET when a discharge over-current is detected and an overcharge is not detected.

Abstract: A method of identifying battery chemistry of a battery in an electronic device monitors voltage behavior of the battery in response to a stimulus. The method can be performed in the electronic device while the device is in normal operation without affecting battery life or the user's enjoyment. Further, the method can be performed many times within the device also without compromising battery life or user enjoyment. A system implements the method in the electronic device. The present invention provides for more accurate battery fuel gauging, such that a battery's end of life is more readily determinable, and allows for various battery chemistries to be drained to their optimal cutoff voltage, and allows for the safe in-device charging of rechargeable batteries that are the same size and shape as non-rechargeable batteries.

Abstract: A battery charging circuit comprises a recharge input and a recharge output with a switching element electrically coupled in series between the recharge input and output. A recharge controller controls a conducting state of the switching element. When in a conducting state, recharge current can flow from the recharge input to the recharge output, thereby allowing a rechargeable battery coupled to the recharge output to be recharged. During periodically occurring intervals, the recharge controller switches the switching element to a non-conducting state such that the recharge current no longer flows to the recharge output. During the intervals, a battery voltage input is sampled to determine a charge state of the battery. The switching element is subsequently returned to a conducting state when further recharging is necessary, or left in a non-conducting state when sufficient recharging has occurred.

Abstract: A first circuit having a first coil electrically charges a second circuit having a second coil through electromagnetic coupling of the two coils. When data signals are to be transferred between the first and second circuits, signal transfer is started only after the second circuit has been charged for a predetermined period of time. The position relationship between the coils is also detected, and a charging/transfer selector changes a duty ratio between charge transfer and data transfer in accordance with the detected result. The charge is transferred in an intermittent manner, and the charging rate is adjusted according to the difference between the voltage of a secondary battery observed during a charging phase and the voltage of the secondary battery observed a certain time after interruption of the charging phase, or vice versa.

Abstract: A device and a method are provided in which memory effects can be cancelled by controlling charging and discharging of a secondary battery during driving of a vehicle. When a memory effect determinator determines that the discharging memory effect has occurred, based on at least one of the following determinations: whether a time of charging/discharging of a secondary battery has reached a predetermined time; whether a charging/discharging amount in the secondary battery has reached a predetermined amount; and whether a voltage per cell has reached a voltage V1 at a lower-limit state of charge in a range of capacity actually used, a discharging controller discharges the secondary battery until the voltage per cell reaches a voltage V3 that is higher than 1.0 V and is lower than the voltage V1 at the lower-limit state of charge.

Abstract: To prevent an erroneous operation of a buzzer upon fall of a source voltage, a buzzer driving device connectable with a direct current source (1) comprises a charging/discharging circuit (3) which is connected with the direct-current source (1) via a switch (2) and performs the charging and discharging at a predetermined time constant (CR) when the switch (2) is turned on and off, respectively, a hysteresis circuit (25) to which an output voltage of the charging/discharging circuit (3) is input and which operates until the output voltage rises to or above an operation threshold value (V.sub.T) after the start of the charging of the charging/discharging circuit (3) and thereafter remains inoperative unless the output voltage falls to or below a stop threshold value (V.sub.S) which is smaller than the operation threshold value (V.sub.

Abstract: A fast charging method and apparatus for secondary cells, especially for lithium ion cells. The charging process has two charging phases. In the first charging phase, a constant current is supplied to the secondary cell from a charging apparatus whilst monitoring the output voltage of the charging apparatus. The first phase terminates when the output voltage of the charging apparatus reaches a predetermined maximum voltage (e.g., 4.2 volt for a lithium ion cell). Then, in the second charging phase, the output voltage of the charging apparatus being monitored and constant current pulses of fixed duration (e.g., 10 seconds) are supplied to the secondary cell in a manner such that the duration of intervals between such constant current pulses is controlled to maintain an average output voltage of the charging apparatus at a predetermined average voltage (e.g., 4.2 volt for a lithium ion cell). The charging is terminated when the duty cycle of the pulses falls below a predetermined value.

Abstract: A battery charger which supplies charging current for a high voltage, high current battery in accordance with a charge profile which preferably includes both a charge pulse sequence as well as a discharge pulse sequence. Charging power is obtained from a three phase power line the voltage of which is reduced by an isolation transformer. Conversion of ac to dc is accomplished by a switching transistor power converter having a control for supplying transistor switching signals. The control is responsive to the angle of line voltage, the actual line current and a reference signal indicative of desired charge current, to generate the transistor switching signals. Any deviation between actual and desired current is then corrected by modification of the transistor switching signals.

Abstract: A battery pack and a method of monitoring remaining capacity of a battery pack. With this method, two different procedures are used to estimate that remaining capacity. In a first procedure, data generated on the battery pack is used to estimate remaining battery capacity; and in the second procedure, data transmitted to the battery pack from a host device is used to estimate remaining battery capacity. The battery pack switches between these two procedures under defined conditions; and for example, with the preferred embodiment described in detail in the present specification, the battery pack switches from the first procedure to the second procedure when the battery current falls below a threshold value.

Abstract: The present invention provides a method for charging a secondary battery and a charger by which it can be prevented that a secondary battery is charged at very high or low temperature, and that the secondary battery is charged for a long time. Therefore, the secondary battery is prevented from being damaged, so that the lifetime can be prolonged. In this method, a generally constant current is supplied from a charging means to the secondary battery. The constant-current charging is stopped when voltage of the secondary battery has reached a peak value after passage of a predetermined time period from start of the supplying of the first current; temperature of the secondary battery has been out of a predetermined range; or a predetermined time period has passed since start of the supplying of the first current.