The 4-amp NiMH fast charger uses a 12-volt DC power outlet for universal high-output charging. The charger is optimized for charging 6- or 7-cell (7.2 volt - 8.4 volt) Traxxas iD Power Cell NiMH batteries. Peak-detection circuitry makes sure the battery receives a full charge every time. The status LED flashes green to indicate when charging is in progress, then turns solid green when charging is complete for foolproof charging, peak performance, and maximum runtime. For NiMH batteries only. Do not use with LiPo batteries.