Digital Battery Meter
To keep an eye on your battery condition most boats have a volt meter of some sort. Older analogue meters have an extended range dial covering approx 10 to 15 volts. They are sufficiently accurate but do not facilitate keeping a record of the meter reading. For this purpose a digital meter is to be preferred. Battery condition monitors have digital readouts but are expensive and in many cases are more than what is required.
As an alternative consider installing a panel digital voltmeter (DVM). These are available over the web for around Â£16 and are easy to fit and connect.
You need a 20V panel meter with or without a switched back light. The back light comes in several different colors and if left on can be a useful low consumption night light.
If you order your meter from Virtual Village(switched part is UP5035A-SW)it will arrives by Post Office mail in a couple of weeks direct from China.
The picture above shows an installation fitted in the starboard quarter berth/engine bulkhead of a Centaur.Also in the picture is a conventional cigarette lighter socket, a 9-way cannon D socket carrying NMEA connections from a GPS and a remote control connection for a ST-2000 autohelm.
Make a cut out in a panel slightly larger than the meter using a dremel. The meter has lugs to engage with a panel to hold the meter in place. Simply press the meter into the cut out.
The connections are simple using four wires which plug into the back of the meter circuit board. The meter needs a 12V supply to operate (two wires)and in addition there are plus and minus sense wires (another two wires). Simply connect the +supply and the positive sense wires together to the boat positive and the -supply and the negative sense wires also together to the boat ground. Virtual Village will supply a connection diagram by email and it is best to ask them for it because the colours are different for different meter versions.
Table of Battery Voltage against %age Charge here: