Samlex Battery Guard BGW-40Samlex Battery Guard BGW 40 The Battery Guard Waterproof BGW 40 is an intelligent, user programmable, fully waterproof battery guard. The battery guard prevents excessive discharge of the battery (which would damage the battery) and protects electronic appliances against overvoltage. The BGW automatically detects the battery voltage (12 or 24V). The BGW 40 battery guard is capable of carrying 40A continuous load and 45A transient load. There is a