Minimum safe domestic battery voltage?

[JeremyF]

What's the minimum voltage it is safe to discharge a domestic battery, below which harm may be caused?

I normally make sure I recharge once its down to 12.2v. Is this overly cautious?

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[snowleopard]

no, it's not overly cautious. regular discharge below 50% capacity will result in premature failure

my copy of nigel calder is on board at the moment but i'm sure other contributors can fill in the details. from memory i think 12.2 is over 50% discharged.

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[Benbow]

Adverc agree that 12.2 v is 50% discharged. For V to be reasonably accurate as a measure of charge state, there must be no other load and the battery must be allowed to 'settle' after delivering any current.

There is no real answer to how low you should let it go. Even deep discharge batteries have their life shortened by being kept partially charged. Certainly you should not leave it for a long period of time as low as that.

Diagram below from Adverc site:

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[JeremyF]

Many thanks for the precise advice. Seems as if 12.2v is about the point to charge up the batteries by engine.

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[Althorne]

If only using your engine to recharge remember that unless you have an advanced alternator or a booster many alternators will only charge the battery to 80% of capacity (no matter how long you run motor) so a 'mains' charger is required once in a while to get the battery back up to full power.

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[JeremyF]

Adverc?

Yes, I was planning to get some box of tricks at the boat show.

Current set up is a 85 aH engine start and 140aH domestic fed behind a diode splitter (so I guess that's even more loss of V's)

Which brand would folk recommend, and are they genuinely easy to install? The two main brands seem to be Stirling and Adverc, the latter seems to command quite a price premium

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[philip_stevens]

Re: Adverc?

I had a Driftgate 2000 charge booster on my last boat for more than 8 years - with no trouble.

Look at <A target="_blank" HREF=http://www.dg2k.co.uk>http://www.dg2k.co.uk</A> for the complete range of charge devices.

<hr width=100% size=1>regards,
Philip

 

[AOWYN]

Re: Adverc?

Can't comment on the Stirling, but have found the Adverc to be excellent on two boats over about 15 years. In addition they are nice people to deal with and the sweets at their boat show stand are delicious.



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[markdj]

Re: Adverc?

Check out this great website

<A target="_blank" HREF=http://www.batteryfaq.org>http://www.batteryfaq.org</A>



MarkDJ

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