Abstract: A device for charging accumulators or batteries provides a substantially constant charging current for a first charging interval until a voltage level which is less than that of a fully charged accumulator is reached. At this time, the device continues charging in a sequence of subsequent time intervals with charging currents which decrease at different rates in each interval until the accumulator is fully charged. The duration of each of the subsequent time intervals and the rates at which the charging currents decrease may be adjusted to shorten charging time while minimizing gasification of water in the accumulator. The device can also be used to maintain the accumulator charged at a given float voltage.