Abstract:
A rechargeable battery (208) is charged using a charger (202). The charge current provided by charger (202) is a stepped-down pulse where the battery charge current rate change is determined by the rise time of the battery voltage. The charge pulse sequence is repeated after the polarization recovery period is completed. The polarization recovery time of the previous period will determine if the stepped-down pulse has to be modified.
Abstract:
A battery pack (12) for powering a device (14) sensitive to input voltage contains a protection switch (28) and a control circuit (26). When the battery pack (12) is charged by a charger (10) and the voltage of the battery pack approaches the maximum safe level of the device (14), the control circuit (26) causes the protection switch (28) to electrically switch open to protect the device (14) from excessive voltage potentially output by the charger. Where the cells (16) are lithium ion cells or a type having a maximum safe voltage, a safety switch (49) is included to interrupt charge current (52) through the cells (16). The safety switch (49) is delayed by resistor/capacitor network (51, 53) so that it switches after the protection switch (28). The safety switch (49) includes a diode (58) to allow the device (14) to remain powered while the safety switch is blocking charge current. Further, diodes (40 and 42) are required to eliminate measurement error of the control circuit (26) if the battery pack (12) is charged through the device contacts (20 and 24).
Abstract:
A battery pack (12) for powering a device (14) sensitive to input voltage contains a protection switch (28) and a control circuit (26). When the battery pack (12) is charged by a charger (10) and the voltage of the battery pack approaches the maximum safe level of the device (14), the control circuit (26) causes the protection switch (28) to electrically switch open to protect the device (14) from excessive voltage potentially output by the charger. Where the cells (16) are lithium ion cells or a type having a maximum safe voltage, a safety switch (49) is included to interrupt charge current (52) through the cells (16). The safety switch (49) is delayed by resistor/capacitor network (51, 53) so that it switches after the protection switch (28). The safety switch (49) includes a diode (58) to allow the device (14) to remain powered while the safety switch is blocking charge current. Further, diodes (40 and 42) are required to eliminate measurement error of the control circuit (26) if the battery pack (12) is charged through the device contacts (20 and 24).
Abstract:
A secondary battery (100) includes a cell (110) having a positive terminal (115) and a negative terminal (120), a device (130, 140) for coupling the positive terminal (115) to the negative terminal (120) in response to swelling of the cell (100), and a fuse (125) coupled between the positive terminal (115) and the negative terminal (120) in response to swelling of the cell (110). According to another aspect of the present invention, a secondary battery (700) has external contacts (150, 155) and includes a cell (110) having a positive terminal (115) and a negative terminal (120) that are coupled to the external contacts (150, 155) during normal cell operation. In response to swelling of the cell (110), a device (705, 720, 725, 730, 735) decouples at least one of the positive and negative terminals (115, 120) from at least one of the external contacts (150, 155) in response to swelling of the cell (110).
Abstract:
A modular battery pack (10) is described having several embodiments. In general, the modular battery pack has a battery cell cartridge (12), a circuit cartridge (14), and a housing (16). In conventional battery packs these three elements are combined into one single unit. The invention modularizes these components such that portions may be reused and shared. This results in a more cost effective power system for a portable electrical or electronic device (40) since, once the battery cell or cells (48) have expired, they can be replaced without having to replace the other components, in particular the circuitry.
Abstract:
A battery charger (12) and battery pack (14) are each provided with a wireless communications device, (24) and (28) respectively, to communicate over a wireless channel (32). The battery charger (12) receives charging information from a memory (30) housed in the battery pack (14), and commences a recharge process in accordance with the received information when the battery pack (14) is electrically coupled to the charger (12). The charger may update the information contained in the battery's memory (30) during the recharge process.
Abstract:
A rechargeable battery cell (10) has an integral vibrating means. The cell has a positive electrode (14), a negative electrode (16), and an electrolyte (18) disposed between the two electrodes. The electrolyte contains a piezoelectric material (20) that vibrates when subjected to an alternating electric field. In one embodiment, at least one of the electrodes contains a piezoelectric material that functions as a vibrating means when subjected to an alternating electric field. In another embodiment, a piezoelectric material that functions as a vibrating means when subjected to an alternating electric field is attached as part of a current collector (22) to at least one of the electrodes. The piezoelectric material performs an additional function of being an electronic insulator for the purpose of stacking the cells.
Abstract:
A battery system (400) for use with portable electronic products which includes protection circuitry for allowing the battery system to be safely recharged in a recharging system. The battery system (400) includes cells (401) and a plurality of controls including an overcharge protection circuit (433) for limiting the amount of current to the cells (401) by a charging network and a thermistor (415) and thermistor control (417) for controlling the state of the thermistor (415) to simulate a high temperature condition allowing the charging network to switch modes and accommodate battery system (400) which does not follow the charging regimen provided by charging system.
Abstract:
A battery cycle counter (48) comprises a rechargeable battery (12) having supply (34 and 36) and charger (30 and 32) contacts, a circuit (14) for providing an input signal when the rechargeable battery (12) is being charged, and a counter (48) powered by the battery (12) and responsive to the input signal which increments a cycle count. The counter (48) has input and output ports. An analog output circuit (44 and 46) coupled to the counter output ports provides a unique analog output signal indicative of said cycle count. This counter allows a user to accurately determine how many times the battery has been cycled. A low cost and reliable battery cycle counter has been lacking in the market.
Abstract:
A battery pack (62) comprises cells (74), and is charged by a charger (64) providing a current level. The charger (64) is a typical nickel-cadmium battery charger providing a first charge current level in excess of an optimum charge current level. The battery pack (62) further comprises a thermal sensing element (76) and an overcurrent charge protection circuit having an overcurrent switch (78), current sense circuit (80), comparator circuit (82), and temperature signal switch (84). If the current level through the cells (74) exceeds the optimum charge current level, the current sense circuit (80) provides a signal to comparator circuit (82) which actuates the temperature signal switch (84), simulating a hot battery pack. The charger (64) then switches to a second charge current level which does not exceed the optimum charge current level. If the charger (64) does not change current levels, a switch delay (86), after a brief period, accumulates enough voltage to actuate a driver switch (88) which opens the overcurrent switch (78), disconnecting the cells (74) from the charger (64).