Battery-charging rectifiers are intended for consumers’ DC power supplies. When a power outage occurs, an uninterrupted supply of electrical power must be guaranteed. In combination with a battery, battery-charging rectifiers provide a secure DC power supply.These battery chargers are implemented in buffer mode as well as continuous battery power supply. For both, charging occurs in compliance with I-U characteristics according to DIN 41 773 norms. The constant voltage depends on the respective operating mode.