Self powered, auto-ranging digital DC voltmeter that accurately measures and displays the output of the status of the on-board battery system. The meter connects to either 12 or 24 volts and provides an input range between 6~30V DC, with red LED digits providing a clear readout to 0.2 volt resolution at a low power draw of only 10 milliamps. The meter is set into a rugged housing that provides protection against moisture and vibration. Supplied with a mounting panel that may be removed to allow flush mounting of the meter only to a maximum panel thickness of 6.5mm.