Charging circuit for balancing charging serially connected batteries

摘要

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.