ABSTRACT
Charging of batteries must be conducted with direct current. Alternative current or rotary current have to be transformed. Mostly semiconductor rectifiers are employed for this task. Methods for battery charging vary with demand and the charging time is of great importance. The charging devices can be divided into those that charge above gassing voltage and those that do not. Chargers that exceed gassing voltage during charging are employed for charging one battery at a time, while the ones that do not exceed gassing voltage can be used for parallel charging of several batteries. The chargers that exceed gassing voltage attain short times for recharge, whereas with chargers that do not charge above gassing voltage very long charging times must be expected.
