Charge your batteries with AC power using battery chargers! Batteries store direct (DC) current; however, because it is more efficient, alternative (AC) current is the type used by household electronics that is supplied by your local utility. Use a battery charger to charge your battery with this current by converting it to DC power. If you are trying to charge your batteries with DC current coming from your renewable energy system or other source, a charge controller is the right solution for you.