The fully automatic 4 Amp Power Tender is a top-of-the-line 12V or 6V switchable battery charger, perfect for automotive, motorcycle and marine repair and maintenance shops. Float / maintenance function maintains batteries at proper storage voltage without the damaging effects caused by trickled chargers. The integrated smart controller assures that your battery is charged safely and correctly at all times through our ISM (Infinite Sequential Monitoring). The ISM adapts to the battery’s needs hundreds of times per second to deliver the proper amount of charge. With reverse polarity protection and spark-proof operation, you can connect it and forget it!