Batterys and hydrogen..

majdrew

majdrew

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Hi Folks!

I need to buy a new battery, which fits underneath my v-berth.

Do you think it's safe to have a standard lead acid battery that you top up? bearing in mind the gasses given off while charging? Or do you think it would be better to get a sealed battery?

The standard batterys seem to be lighter in weight, and I'd heard that they last longer due to to fact that you can service them, so that was my initial idea.. but then I thought about the gasses while sleeping/explosions..!!!?

Any thoughts much appreciated.
Thanks!
 
had 3 boats of my own ... my Father had numerous boats - all with standard lead-acid batt's under the cabin divans or in lockers ... only one boat I sailed on was battery not in main cabin.

If you overcharge - of course gas will be produced more, but H is a light gas that disperses easily - just make sure no-ones smoking over top when you open the box.
 
Modern batteries with decent charging systems gas very little. The proof of this that you rarely if ever need to top up. You can't gas without losing water.
Gassing on charge was a real problem when the lead was alloyed with up to 10% antimony which lowered the potential at which it would gas. Consequently float charging had to be below this voltage, the battery would gradually lose condition and the you would periodically have to boost charge above the gassing voltage to revive it. In vehicle systems this was made worse by low performance badly regulated dynamos.
Using a modern low antimony (<2%) or calcium alloy battery and a well regulated mains charger or engine alternator significant gassing should never happen.
I'm surprised you reckon the sealed battery is heavier - would normally be lighter. That's assuming you mean a real sealed battery i.e. valve regulated gas recombination. Don't fall for the "sealed maintenance free" wet battery, which is just a wet battery without top up plugs and maybe an increased liquid reserve.
 
Mmmm with modern batteries I expect there is less of a risk of hydrogen build-up but I would still recommend the enclosed area is ventilated in some fashion, a simple 25mm pipe or two to vent externally or to a larger void is better than nothing!
 
I would certainly agree if you have hundreds of Ah capacity in a big motor boat on charge all the time.
I'm guessing the OP is talking about a small auxiliary engine battery - sorry OP if I'm guessing wrong but you have got that picture there....
Mike
 
That's great thanks for the reply everyone. It's a 130AH house battery I was thinking of, and what's been said has reassured me..
I'm off to Plymouth battery centre next weekend to fix myself up!
All the best everyone!
 
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