If you have more than a single PV panel, or more than a single source of power (wind and PV) then you need a charge controller. This piece of hardware will provide the battery (or batteries) with the optimal current to keep them charged. More expensive models may have a number of other features like:
- LED charge status indicators
- temperature compensation charging
- overvoltage protection
- low voltage alarm
- high voltage disconnect
- high temperature disconnect
- lightning and transient surge protection
If you only have one panel and one battery, you can leave the system in permanent circuit, with a constant trickle charge to the battery. I have had such a system sitting basically idle for five years now, doing just fine. --Eric 27 April 2006
- This depends on the size of your panel and battery. A large panel that has an IV curve showing significant current above the 14.5V range can destroy a small battery or even a large battery with small or infrequent loads. A very simple charge controller, i.e. just a voltage regulator, is very important in any RE/battery system. --201.135.20.155 05:42, 1 July 2006 (PDT)