Smartpacks are sealed, VRLA batteries with onboard chargers that can be plugged into any 15A, 120V AC line. The fully automatic, integral battery charger is matched to the battery to maintain peak performance with plug-in convenience. There's no supplementary equipment or charger installation needed. And because it's sealed, it never needs water! Smartpacks are available in up to 600 A.H. We also offer PROPack - a 24 volt system consisting of four sealed batteries connected in a series/parallel configuration.