Battery Mystery (Misery)

[DKnight]

Batteries were great all summer long, 2 no. 125 amp/hr domestics and a 80 amp/hr engine. Well I left them on board as I was going to do some re-wiring during the winter fit out ( new GPS, Gas Detector etc.).

Two weeks ago went to the boat stuck the charger on for an hour or so to give them a bit of a kick, then after after running lights after another 3-4 hours the batteries had gone flat! (Had the engine mechanic done his worst?)

So I gave them a good charge up for a couple of days, only to find last weekend, they still would not hold a charge. I checked then electrolyt/ water level and all was fine. However to my horror I could see the plates on the two domestic's were distorted.

What could have caused this? I do not know of any short circuit, but all my rewiring was in relativly light stuff, and if shorted would have glowed in the dark!
Did I over charge or cook the batteries - but yet the water level was fine?

I am concerned that I have a problem and if I fit new batteries I might immediatly damage them as well. The old batteries were installed May ' 99 and are of the Heavy Duty Leisure (Varta) type.

Any comments would be appreciated.

D>K

DK

 

[mtb]

Sounds like over charging to me , it does not follow that the electrolyte level will go down re over charging.
Has your engine got a separate regulator if so get the out put checked.
how old are the batteries and finally it is normally the cold that finally kills off a battery.

There was a recent post that went through the battery stuff have you tried a search
cheers
buttercup

smile you'l be on your boat soon ;-)
<A target="_blank" HREF=http://homepage.ntlworld.com/boats/>http://homepage.ntlworld.com/boats/</A>

 

[Trevor_swfyc]

Batteries should last longer than 3 years but if left flat for a period of time then this is a certain killer of batteries. Did you get a 3 year guarantee? it is a mystery how items such as batteries die just as the guarantee runs out.
Sorry but it sounds as if will have to fit two new batteries if the current ones are not accepting let alone holding a charge. Try Camping & General for domestic batteries thats watt I would do!
Trevor

 

[snowleopard]

Sulphate?

could be that the cells have sulphated as a result of being left. there is a partial cure for this which is worth trying before consigning them to the skip: take them to a specialist battery shop and get them 'equalised'. this involves heavily overcharging them at 15.5 volts or more. they need to be supervised as they will gas heavily and need regulat topping up during the process.

one charger i saw at the boat show had the facility to do this in situ.

got to be worth a try.

 

[c4pt]

Just a thought, Check and clean all connections from the battery on both terminals. Especialy any earth that goes to the engine block. I had a car that caused me 18 months of severe stress and defide all the 'experts' in the end it was just a faulty earth connection.

 

[ccscott49]

Are you sure it's the plates distorted? Sometimes when you look inside the batteries, it appears they are distorted, but it's only the dividers, which are sometimes a little wavy. Anyway, the best solution here, is to get them out and take them to a battery specialist and as has been said, get him to work on them, if sulphated, they may also be able to flush them out and refill, this can help. I hope you get them sorted, as new ones aren't cheap. When and if they sort them for you, you need to put an ammeter in series with your main feed to the general domestics, and switch eaqch circuit on at a time and see if there is a short. After that, it's up to you to decide.