The maintenance device is suitable for all common 6V and 12V lead-acid batteries (lead-acid, AGM, gel, CaCa, maintenance-free, open). Recommended battery capacities: 2Ah to 240Ah. The microprocessor controlled charger automatically detects the voltage of the battery, the state of charge and the need to maintain the charge. The trickle charge process begins as soon as the battery voltage drops to 13 volts (for 12 volt batteries), or 6.5 volts for 6 volt batteries. The German language display is easy to understand. The innovative battery trainer is equipped with the latest battery charger technology and charges batteries so that they always remain at a constantly high level. This serves to maintain the highest possible battery capacity and a constant availability of sufficient voltage to start your vehicle (car, motorcycle, scooter, quad, ATV or boat). The device is suitable to remain permanently, e.g. over the winter, on the battery, as it automatically switches the charging process on and off. An LED display informs about the operating status, full charge or faulty connection. Modern safety technology with reverse polarity protection, overheating protection, overload protection and short circuit protection protects you and the device from incorrect operation.