Charging problems part 1

The fridge on board Willow is more of an electric coolbox than a proper fitted fridge. In the door it has a fan which runs noisily all the time - so at night we unplugged it. On the second morning I reconnected it and tried to recharge some batteries via the small invertor. Hmm - invertor not working. I checked the input voltage - should be nominally 12V - actually 9.63V. Oh dear - the leisure batteries have run down. A lot. I started the engine and checked again: still the same. Bigger oh dear: the leisure batteries aren't charging at all. The alternator's fine as it's charging the starter battery, so we cruise from Grappenhall to Lymm (yes, I've jumped back slightly) and stop for Jan to get some provisions while I disappear down the engine hole to try to work out what's going on. Checking voltages at the split charge relay leads me to suspect that the relay is faulty (I was wrong, but I didn't find out the real problem until almost the end of the holiday).


the split charge relay

A boater who was tied up behind me suggested connecting the positive terminals of the leisure batteries to the positive of the starter battery (with the engine running) to bypass the relay. Good idea, as long as I remember to disconnect when I stop the engine (or there's a risk of flattening the starter battery). I had a pair of meaty jump leads with me so, in an instant, we had cabin power again. Hooray! (I had to be really careful when jumping the batteries: making sure that I was holding the free end of the jump lead well clear of any metalwork while connecting the other end to one terminal, before connecting the free end to the other terminal - and keeping the "negative" lead well away).

The next morning, at Worsley, I did some more voltage measurements. These seemed to confirm the diagnosis, so I walked round to the Worsley Boatyard to see if they had any spares. They didn't, but offered to order one for me. They also suggested Bridgewater Marina, just a bit further on at Walkden, might have one. In a short time we'd cruised there ... and they were friendly too. To the extent of giving me one exactly the same which they'd just taken off a boat!

I fitted it straight away, and it seemed to fix the problem. Result! We went on our way, passing Elk outside the pub.