The DEFA battery charger operates when the system is connected to the 220/230 V mains supply. An electronically controlled charging curve, coupled with advanced charging electronics, prevents overcharging, which can damage the battery. When the battery is fully charged, the charger switches to top-up charging. The charger includes a temperature compensation feature, so that the battery is correctly charged in all temperature conditions. The charger has an integrated relay-function wich controls the mains to the engine- and interior heaters. This function is controlled by the Control unit. Our new Switch mode technology has allowed us to develop lightweight, compact battery chargers. This has significant advantages when it comes to installation, because it is easy to find a suitable installation site. The charger is light-weight, which means that it can simply be strapped to the bodywork.