Nature Power 1.5-Watt Solar Battery Maintainer takes the sun's energy and turns it into electric current and delivers a small current to your rechargeable 12-Volt batteries to promote the longevity and health of the battery. The Solar Battery Maintainer also combats the effects of cold weather on your battery ensuring quick starts through the winter months. A great alternative to traditional battery chargers since no AC power is required. The Solar Battery Maintainer may also be used on boats, ATVs, as well as farm equipment such as deer feeders, lawn mowers, and battery backup sump pumps.