Battery Condition Monitor

Meter installed above switchboard

Photo from ASAP's website

Now that Patience has had an electric fridge installed (see 7 August 2014 entry) we have to be more careful with our power consumption when moored up overnight. The Shoreline fridge is claimed to consume an average of 0.95Ahr/hr so mooring up for 18 hours would, in theory, consume about 17Ahr from the two domestic batteries.  They have a nominal capacity of 2 x 110 Ahr so allowing for 50% of that being accessible, that would represent 16% of their capacity. However mooring up for two nights (say 42 hours) would consume 40 Ahr or 36% of their accessible charge.  To that has to be added the power for lighting, pumps, TV, etc and in any case, the batteries may not be 100% charged when mooring up.  Therefore it is essential to keep a watch on the state of charge of the batteries and to preserve the starter motor battery by switching over to the domestic batteries when mooring up for the night.

We therefore purchased a Faria battery condition monitor from ASAP, our preferred marine component supplier.  It was ordered on a Friday afternoon and arrived via Royal Mail the following morning.  What fantastic service from ASAP and Royal Mail! The gauge has been installed above the switchboard on the aft bulkhead, as shown in the top photo. The detailed photo of the gauge is from ASAP's website. The manufacturers recommend that it is wired via a switch so that it can be switched off when the batteries are being charged by the engine.  A convenient spare switch on the switchboard, also incorporating a circuit breaker, was used for this purpose.