# 15.3v wet lead acid



## coppo (May 27, 2009)

The wet lead acid batteries have today been charging at 15.3v, is this too high or are sometimes they meant to do this? To give them a good charge and stop them sulphating.

The inverter was showing as a fault and the radio would not work when the display showed 15.3v

The voltage has now gradually gone back down 14.7, 14.6, 14.4, 13.9, now 12.9.

The sun is shining and we have 280W of solar, no hook up.

Paul.


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## sallytrafic (Jan 17, 2006)

If your batteries are very cold 15.5V is at about the top limit for an equalisation charge. So as long as it's not happening all the time I wouldn't be too worried.

I would check electrolyte levels periodically.


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## pippin (Nov 15, 2007)

I would agree with the answer given by my Honourable Friend.

But, it is a bit high for my liking so I would be checking further in case the solar regulator is faulty.

Try measuring the battery voltage at different states of sunshine.


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## coppo (May 27, 2009)

sallytrafic said:


> If your batteries are very cold 15.5V is at about the top limit for an equalisation charge. So as long as it's not happening all the time I wouldn't be too worried.
> 
> I would check electrolyte levels periodically.


Thanks Frank

No its not happening all the time, yesterday was the first time i noticed it, just not noticed it before with the previous gels(now have 2 6volt wet ones).

They are now showing 14.4V, according to the Sterling management panel there is 1Ah left to put back in and +3.5Ah going in.

So alls well, thanks.

Did chack the levels last night after we had used some power, levels fine.

Paul.


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## Touchwood_RV (May 1, 2005)

*Use more fluid*

As stated above by Frank I don't think you have an issue here - unless it becomes a very common occurrence.

I don't have solar panels but have seen 15.4V from my 3 stage mains charger a good few times, and for prolonged periods of time.

I know you have, but I would strongly recommend having seen it and it was for more than just a few moments where the charger was trying to compensate for something or other, check the fluid levels more often than you would normally as that rate of charge can cause excess boil off. When my 6 Volt babies hit that level of charge they do tend to use a tad more fluid.


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## 747 (Oct 2, 2009)

You should have an Electrobloc unit fitted to your van.

If you were previously using gel batteries then the switch on the EBL will be switched to 'gel'. Now that you have lead/acid batteries, you need to move the switch accordingly from gel to lead/acid.


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## coppo (May 27, 2009)

Thanks all

The electroblock switch is set correctly to wet, confirmed by Peter Hambilton 2 weeks ago.

Touchwood RV, when you say 'for prolonged periods of time' how long roughly do you mean, a few hours?

Yesterday afternoon they did the same(went to 15.3v), up and down from 14.4 to 15.3, strong sunshine, checked the levels again last night, all fine.

Paul.


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## sallytrafic (Jan 17, 2006)

Paul have you an instruction book for the solar regulator. Most only perform a equalisation charge once in a while. Mine does one every ten charge cycles some count off periods ie nights and do one after 10 or 20 nights. Others might wait a specific time before doing one. Note these can be fooled though.

Doing an equalisation charge every day can lead to over gassing and loss of electrolyte.

How long depends again on the regulator the longest I have *seen* mine do it for was about an hour.


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## cabby (May 14, 2005)

slightly off topic, but may I ask why you have 2x 6 volts, is it to do with space.

cabby


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## coppo (May 27, 2009)

Thanks Frank, we have a 120w panel going through a FOX-D1/E regulator, this is not putting anything in according to the display when the batteries are full(14.4 -15.3V) so appears to be working as it should.
X2 BP 80W panels going through a Steca Solarix MPPT 2010 regulator, this appears to be working correctly when the voltage is high, the green lights flashes quickly which indicates battery full, charge regulation active, charging current reduced. So again no faults showing.

I,ve looked and the equalisation voltage for these Rolls 6 volts is between 15.48-16.02.

Could it be that we have been without hook up for a few weeks and the batteries did not receive a proper full charge and when the sun has really shone the last couple of days they have now been fully charged?

Do these batteries because they are substantial ones need a good charge?

The Sterling display now shows 14.3 with 5.7 going in and -3ah on the ampere display so not quite full yet after last nights useage.

Cabby, wanted some quality ones as we spend long periods in the van.

Paul.


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## sallytrafic (Jan 17, 2006)

Ah of batteries?

Rule of thumb is C3/10 (ie 3hour rate for battery divided by 10) as the maximum charge rate Some people allow C3/5) Now assuming you have to put 50% back the shortest possible time is 5hrs whatever the size of battery. 

Relying on Solar to give you anything like C3/10 for the whole 5hrs might work if you have enough pv panel in June.

Wow Rolls batteries - quality,  respect. 

A better answer for Cabby is that by using a single series string of 6V batteries you get away from strings in parallel with their problems of circulating currents and cells not charging equally. With a single string all the current goes equally though all the cells.

Of course you may have parallel strings of 6V batteries even more Rolls batteries


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## pippin (Nov 15, 2007)

Nothing quite like using individual 2V cells - ask yourself why the GPO used them in virtually every telephone exchange.

If one cell goes down in a 6V or 12V battery then the whole thing is junk.

By making regular visual inspections of electrolyte level through the glass containers and by taking regular specific gravity readings potentially (!) dodgy cells could be individually replaced.

The trouble is for us in MHs there is trade-off between the extra weight of individual cells and batteries of them.
6V batteries have a 1 in 3 chance, 12V a 1 in 6 of having to throw out good cells.


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## coppo (May 27, 2009)

x2 Rolls 6FS 220 ah and 280w of solar. So 220ah in total.

Cabby, thats exactly the explanation i meant  

Paul.


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## coppo (May 27, 2009)

they are now up at 15.2v and still putting 1.5ah in, according to the sterling panel.

Paul.


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## coppo (May 27, 2009)

Stephen from Aire and sun came out to look today, it looks like the problem has been the 2 solar systems not working together, one works without the other and vice versa, so we have the x2 80w connected through theSteca mppt regulator, the 120w through the morningstar is diconnected.

Stephen will email Steca to try find a solution, he says they cant all be put through the Steca as they are different wattages.

Paul.


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