Samlex BGW-40 Waterproof Battery Guard - 40 Amps [BGW-40]BGW 40 Waterproof Battery Guard 40 Amps The Battery Guard Waterproof BGW 40 is an intelligent, user programmable, fully waterproof battery guard. The battery guard prevents the excessive discharge of the battery (which would damage the battery) and protects electronic appliances against overvoltage. Includes Automatic Board System Detection, the BG automatically detects the battery voltage (12 or 24V). The BGW 40 battery guard is capable of carrying a