Victron BP-65 Battery Protect

The BatteryProtect disconnects the battery from non-essential loads before the battery is completely discharged (which would destroy it) or while it still has enough capacity to start the engine. The alarm output is activated if the battery voltage drops below the preset value for more than 12 seconds. Starting the engine will therefore not activate the alarm. The alarm output is an open collector output to the negative rail, with a maximum current of 50mA. The alarm output is typically connected to a buzzer or a light signal. The load is disconnected 90 seconds after the alarm is triggered. If the battery voltage rises to the 'connect threshold' level during this time (e.g., while starting the engine), the load will not be disconnected. In the event of an overvoltage that could damage sensitive appliances, the appliances are disconnected if the DC voltage exceeds 16V or 32V respectively.