Charging voltage distribution apparatus for series batteries

Abstract

A charging voltage distribution apparatus dedicated to a charging apparatus for charging batteries connected in series comprises bypass circuits 15A and 15B connected in parallel with each of batteries B1, B2, etc. and a control circuit (consisting of circuit elements 4, 5, 6, 7, 8, 9, 11, 12, 13, and switches) for controlling amount of current to be routed into the bypass circuits 15A and 15B according to the voltage of a battery connected to the bypass circuits 15A and 15B. When the voltage of the battery exceeds a predetermined value, the control circuit makes the current to be routed into the bypass circuits 15A and 15B. When the batteries B1, B2, etc. connected in series have voltages exceeding the predetermined value, current is routed into the bypass circuits 15A and 15B. When the batteries have voltages lower than the predetermined value, charging current is fed for charging. Switching of current from the battery to the bypass circuits 15A and 15B or vice versa by means of the control circuit is achieved by making or breaking the switching devices SW1 and SW2 in the bypass circuits according to the voltage of the battery. The amount of current to be routed to the bypass circuits is determined by controlling the making and breaking durations of the switching devices.