We are offering Elight solar charge controller. A charge controller, or charge regulator is basically a voltage andor current regulator to keep batteriesfrom overcharging. It regulates the voltage and current coming from the solar panels going to the battery. Most "12 volt" panels put out about 16 to 20 volts, so if there is no regulation the batteries will bedamaged from overcharging. Most batteries need around 14 to 14.5 volts to get fully charged.Elight industries Kerala