CTEK (56-674) Multi US 25000 8-step, Fully Automatic 12 Volt 25 Amp Battery Charger Fully automatic 8 step charger maximizes the life of the battery by reconditioning, charging and maintaining the battery Spark free and reverse polarity protected, making connecting to the battery safe and easy Water and dust resistant making it great for working in the shop or out in the elements Specially designed to work safely with todays high end electronics in vehicles with no need to disconnect battery Patented method for reconditioning sulfated batteries that have been sitting for long periods of time