The Samlex 12 Volt 8 Amp Solar Charge Controller is waterproof. Attach it to your solar system (up to 130 Watts). The SCC-1208L is a Series Type of PWM (Pulse Width Modulation) Charger Controller. It's based on an advanced design using a microcontroller for digital accuracy and fully automatic operation. The PWM battery charging has been optimized for longer battery life.