Smart battery charger and maintainer with multi-stage charging cycle The OSRAM BATTERYcharger 904 is a 4A smart charger and battery maintainer for 6V and 12V vehicles including motorbikes and most smaller vehicles. 7 stage charging cycle at the touch of a button for Lithium batteries with only a 9-stage cycle of Lead Acid/AGM batteries. Connect and be sure that the car battery charger is maintaining your car battery as it automatically adjusts to long-term maintenance mode when battery is full. Includes a digital display to make the charging process easier and a host of safety features including reverse polarity and short-circuit protection.