The fully automatic Battery Tender® 4 Amp is a top-of-the-line 12V or 6V switchable battery charger, 12V Lithium (LiFePO4) perfect for automotive, motorcycle and marine repair and maintenance shops. With 3x the power of the Battery Tender® Plus, this charger is versatile and powerful. Equipped with a simplified four-step automatic charge process. All Battery Tender® chargers automatically switch from full charge to float charge mode. Reverse hook-up protection makes connecting your charger safe and easy to do. LED light indicators make selecting your charge mode simple. 12V or 6V switchable @ 4 Amp. Selectable for AGM / Standard / GEL or Lithium (LiFePO4) *12V only for Lithium. ISM™ (Infinite Sequential Monitoring) of the fully automatic four-step charge process (qualification, bulk charge, absorption, float). Microprocessor controlled. Spark proof even when output leads touch.