A battery protection device for disconnecting a plurality of batteries from an inverter to avoid excessive discharge. The device comprises at least one battery connector for connecting to the plurality of batteries, at least one inverter cable for connecting to the inverter, and a plurality of wires for connecting to an AC input. The device gets activated when the AC input to the inverter cuts off and continuously monitors a voltage level of the batteries. Further, the device automatically disconnects the batteries from the inverter at a preset voltage level and shuts itself off to achieve a protection mode wherein the device does not draw any current to avoid further drainage of the batteries. A voltage level of the device is set above a preset voltage for recharging batteries and when the AC input is restored, the device reconnects the batteries to the inverter.