The NWCC sailing club has it’s annual shakedown cruise on Easter Saturday (that’s the day after Good Friday and before Easter Sunday. The shakedown is a trip out to (and around) Puffin Island, and it gives the boats (and boaters) every opportunity to find out what needs to fixed/replaced/thrown away before the sailing season starts up.

I went up to Deganwy the weekend before the shakedown, to do some tidying up and work through my list of jobs. I fell at the first hurdle when the engine wouldn’t even turn over. There was power but not enough of it. I got the voltmeter out and it showed the Number One battery had 4.1v when attempting to warm the glowplugs. Well yes. That’s not good enough. Fortunately I had my superdooper car battery charger with me, because I was a Boy Scout for one whole day. I connected that to the Number One, flipped it on to assisted start (kind of a ‘fast charge’ setting but with steroids), turned the key and the engine effortlessly fired up. Yay! But also… was it yay?

I wasn’t able to complete all the jobs (or make much headway through the list) because all that stuff took much longer than it took for you to read it. For example, my credit on the electricity point had mysteriously gone to zero, so I had to put some money on that. There were other problems, but let’s just assume it took a couple of hours. So some jobs weren’t done.

I planned to go back up to Deganwy on Good Friday, connect the charger to the Number One battery and give it twelve hours of fast charge. I planned to spend the night on the boat, because of the jobs and having to sail out before High Water the next day. Still, I felt the battery problem had been overcome and I’d done enough for Saturday’s trip. I only needed power to start the engine in the marina, and to restart the engine to get me back down the Conwy and into the marina after the shakedown. But… as time passed I began to feel less confident about the latter part of the planned cruise. What if the battery is so shot it won’t hold a charge for five-ish hours? What if it won’t start the engine for the return trip, and I’m stuck out at sea? Well that’s not good, obviously. Less than ideal, in fact.

I’ve been doing a lot of thinking about and researching the problem. This has involved a deep dive into the murky world of 12v marine electronics – and wouldn’t you just know that 12v marine electronics is a different place to 12v car (for example) electronics? And 12v caravan electronics. And any other kind of 12v electronics. My reading (of some exceptionally long and wonderfully dull articles) told me that a 12v battery with 4.1v was actually dead. Pretending to be alive, certainly. But actually dead.

So the plan changed. I was still going up on Good Friday but I would remove the Number One battery and fit a replacement. By the way, the battery compartment looks like this:

As you can see, there’s rather a lot going on in there. That’s the Number One battery at the top of the photo. The Number Two battery is for housekeeping, instruments, and other electrical needs when the engine’s not running. The Number One battery is a starter battery. The Number Two battery is a leisure battery. These are two important facts, hold on to them.

So here I was with a dead Number One battery. I wasn’t really concerned about Number Two for now. I wasn’t planning on using a lot of instrumentation for a bob around Puffin. A bit of VHF radio, but nothing else was really needed. And if the worst came to the worst, I could run the VHF on the Icom handheld. I was planning on turning the AIS off (there are over twenty boats taking part, the noise from the AIS detecting 20+ boats in close proximity would be endless). Depth instrumentation would be good, but I could live without that if required. But a dead Number One was a show-stopper.

I started phoning around and hahahahahaaaa, the amount of companies who had a 12v marine starter battery on their shelves was somewhat less than optimal. Also it was less than one. And so I arrived at Thursday morning, still no solution to my problem. If the worst came to the absolute worst, I thought, I could put a car battery in and… then I read up on the perils and pitfalls of that course of action and rapidly dismissed it.

So I put out a ‘help’ on the sailing club WhatsApp group, explained the situation and asked if anyone could offer advice. Straight away Arthur (who taught me to sail Good Mood) came back. He gave me the name of an auto electrical supplier in Mochdre. I gave them a call and this is where it gets really interesting.

They asked what the dead battery was. I read the detail off the photo. They said ‘That’s not a starter battery, it’s a small leisure battery.’ and I said well blow me down (or words to that general effect). They had more questions, some of which I couldn’t answer, so I sent them the above photo. They called back and said it was definitely the wrong battery. It (and the other one in the photo) are both leisure batteries. They also said that as well as being the wrong battery, it was an odd one, because it had two threaded poles which were open and unused. I asked if they had a marine starter battery of the same dimensions and they said… Yes! And it would be cheaper! Then I asked what their hours were tomorrow so I could pick it up and they said they were closing at 5pm today and wouldn’t be open again until Tuesday morning. I asked if I could pay for it over the phone and get someone to pick it up today and they said ‘Yes!’. I really liked these people.

I went back to the WhatsApp group and asked if someone could pick up the battery from Mochdre and Arthur, again, came to the rescue, saying he was going there later to pick up a new one for himself. I called ABC Auto Electrics, Mochdre, and paid Richard (who is a top bloke and full of helpful). Then I notified Arthur the battery was ready. Half an hour later, Richard messaged me to say Arthur had collected the new Number One battery and the receipt was with him.

So tomorrow, Good Friday, I will still be going up to Deganwy, but this time I shall be disconnecting all that red and black cabling, lifting out the defunct Number One battery and easing the new one in. When all that spaghetti is reconnected, the engine should roar into life and Robert should be your Mother’s Brother. Fingers crossed I can fiddle that cabling off and back on, eh? Hopefully, after all that nonsense, I should be able to crack on with the list of jobs I didn’t get done last weekend.

3 thoughts on “Battery=flat

  1. I think that if a rechargeable battery falls below 10.8V, it is usually considered dead. Yes, it can be charged up, but it won’t hold a charge like it used to. So, 4.1V means it’s a definite goner.

    But, 12V being 12V, I can’t see why a car battery can’t be used.

    Nice to see that the boating community help each other out in much the same way as the motorcycling community.

    1. At rest the battery returned 10.2v which was borderline OK-ish. But when I warmed the glowplugs it dropped to 4.1v and that was the point at which I thought it was a non-starter. Non-starter! See what I did there? Anyway. Marine 12v batteries have different thickness cells (or something inside that’s a different thickness) because of all the salty goodness in the marine atmos.

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