Batteries or Windlass?
We knew our anchor windlass was poorly. It was starting to slip and was clogging. By clogging I mean that the chain was getting caught above the hole that it fed into to go into the anchor locker. So when pulling up the chain it would clog and I would have to let a bit out again and slowly let it in again … before it clogged again.
The windlass is controlled by two foot switches, it is quite a knack to get it to go slowly. It seemed the motor was working fine but the was something that was lose that was sliding across the access hole the we were pulling the anchor up. Paul had already tightened the fixing bolts down and was surprised to find them all very loose indeed. The act of tightening up the bolts actually finished then off and within a couple of days of anchor action, the clogging was worse than ever.
A serious investigation was called for and Paul went in with his tools. He came back with bad news. “Looks like it’s a new windlass rather than the batteries”. Oh this wasn’t good! How were we going to manage with our current batteries with the imminent arrival of Sophie!
“We won’t get to pick up Sophie if we don’t have a new windlass” Paul explained. The though of picking up Sophie without new batteries was a little scary. Let me explain.
For a while our freezer had been at best a beer fridge. That is good enough to produce ice cold water and wine, not good enough to produce ice for Gin and Tonic! I will try to explain why.
We have 5 batteries on board. 4 house batteries and 1 starter battery. Our total output for the house was 400 watts. Please bear in mind that I am a girl and I am ok with maths but useless with physics, so even the thought of watts and amps turn my brain to mush. Paul has explained this a million times to me but I obviously am blocking it from going into my Brian or being stored there. I expect Paul will correct this before you read it, but if not I will apologise in advance if I get this completely upside down and the wrong way round.
We had calculated (because I like doing the maths) that we required 1100 watts of power in a 24 hour period. This was taking into consideration a one third duty cycle for the fridge and the freezer. (so on the assumption that these devises are pulling power for 8 hours out of 24). We divided 1100 watts by 12 to get 91.6 amps (rounded up to 100amps) in a 24 hour period. We calculated using 12 hours of daylight and 12 hours of no solar charge, we also read that we should only be using 10% of the battery capacity therefore we would require a battery bank of at least 500 amp per hours to give us the 50amps required each night when the solar wasn’t working.
So we currently have 400 A\h with the current batteries, and they were engine start batteries not deep cycle batteries. We had already replaced one battery (with a dual purpose battery) which had starting getting very hot and we had just discovered another battery was seriously on its way out.
Paul’s explanation of a deep cycle battery as apposed to an engine start battery is this:
An engine start battery is like a sprinter … it can give a lot of charge over a small amount of time. A deep cycle battery is more like a long distance runner giving out less charge over a much longer period of time.
So I understand why we need the right sort of battery for the job, and I can understand why we were having difficulty getting the batteries to recharge fully despite us having double the solar panels and sunshine than we ever had in the UK. Maybe I will get to grips with the physics of batteries after all. Homeschooling is the way to go ….especially if you live on a boat!
At night we were turning off the freezer, we had the anchor light on and a fan running, but still we were draining the batteries down much further than we should have been. We were struggling to keep the fridge and freezer cold, in fact, we had started using the freezer as a beer fridge, which kept the water and wine icy cold but didn’t actually freeze anything.
So here we are with 4 batteries being over extended every night and still providing not enough power to get us through. We had had to run the generator every morning for the last two weeks to get the batteries back up to 12 volts in the morning. And still no ice in the freezer.
Now my concern was that even if we replaced the batteries (at vast expense) was it the fridge and freezer that needed replacing as they were taking soooo much power, or, even worse, our 7 solar panels, were they producing the power they should be. What if we replaced the batteries and then realised that it was the other equipment that was the problem and we still would have no ice!
Decisions, decisions!
Such a dilemma! But then another battery over heated … we were down to 3 batteries so something needed to be done, and quickly! We now didn’t have much choice. We had to have a new anchor windlass and we had to have new batteries and we could just hope and pray that we didn’t need new fridge or /and freezer or solar panels at the same time.
So decisions made … we needed to find new affordable batteries that fitted into the space we had but provided us with the extra power that we needed to run the fridge and freezer and we needed a new anchor windlass as well.
