| 摘要 |
A battery charge control circuit (10) senses the charge condition of cells in a battery pack (12, 14, 16, 18) using measurement circuit (51). Upon detection of a single undervoltage cell, the charge control circuit is placed in a sleep mode. Pack sense circuit (240) senses when the battery pack is placed in a charger. If circuit (10) was in a sleep mode, it is awakened. If any cell is measured over-voltage, the status is checked versus the other cells. If all the cells are over-voltage, the battery is considered balanced. If one or more cells are not over-voltage, control circuit (32) activates a discharge transistor (212, 214, 216, 218), discharging the cell within a hysteresis voltage below the over-voltage limit. Charge balancing of cells is continued until the cells are within a programmable hysteresis voltage of each other.
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