Einhell power x change systems einhell 4511357 the einhell power x change 18 volt 52ah li ion battery features a 7 in 1 active battery management system and a 3 step led battery control the microprocessor controls key parameters like temperature voltage and even a deeply discharged battery can be charged in repair mode and offers a long working battery life the high quality li ion battery cells provide extremely low self discharge and the rubber coated housing gives high impact protect