# gel batteries



## forterotwins (Feb 25, 2008)

Hi all
I have gel a battery fitted to my dethleffs it has worked really well up until a couple of months ago for no reason it seems to loose it charge from 13.5 to 11.5 in about a week nothing is left on but we leave the 12 volt system switched as we have always done .
The battery is five years old is this the expected life of a gel battery or could this be a a problem with something draining the battery i do not want to go out and buy a new one if its ok .
is there a way of testing the battery to see if it is holding its charge??
any help appreciated


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## Touchwood_RV (May 1, 2005)

*Gel Batteries*

Hi forterotwins
Batteries are defined as having a life expectancy based on charge/discharge cycles. I.e. one life cycle is starting at maximum charge to a discharge of around 20%, from which point you recharge back to fully charged. Most battery manufacturers rate their batteries based on this and the quantity of cycles will depend on the make size and quality etc but as rule of thumb you could estimate up to 600 cycles. I presume the GEL you note is the house battery? The big issues even with GEL the longer they sit around the more they can sulphate. This is all guess work as I have no idea what your load and life cycle has been but I would suggest that at 4 to 5 years lite use with not running at full life cycles at times is about the limit, i.e. they are not holding their charge. As for testing there are various way assuming you can apply a steady known load and accurately measure the discharge rate etc. Or better still I recommend take it fully charged to a good quality battery retailer and ask them to do the appropriate load testing for the battery type size.
Don't buy until it is fully tested, but it sounds like its time for a new one….
Hope that helps?


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## BillCreer (Jan 23, 2010)

I have just replaced my 11 year old gel with 2 newer ones. I didn't change it because of any fault it's just that I wanted a matched pair.
A 2 volt drop is about what I would expect with 1 cell failing but the only way to tell is by getting it tested.
Is it getting hot when on charge?


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## BillCreer (Jan 23, 2010)

I take that as no then


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## forterotwins (Feb 25, 2008)

*sorry*



BillCreer said:


> I take that as no then


 Sorry Bill in delay will check that out thanks for tip
lawrence


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## Mikemoss (Sep 5, 2005)

Not sure if this will be of any help as my only experience of a gel battery is the one in my wife's Mazda MX5. The car gets infrequent use (a bit like a motorhome I guess) and the battery has flattened itself a couple of times.

The first time, it recharged OK overnight using a Sterling digital charger.

The second time it stayed resolutely dead until the supplier told me it would need to be left on charge for one week. He was right - it's fine now.


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## forterotwins (Feb 25, 2008)

Mikemoss said:


> Not sure if this will be of any help as my only experience of a gel battery is the one in my wife's Mazda MX5. The car gets infrequent use (a bit like a motorhome I guess) and the battery has flattened itself a couple of times.
> 
> The first time, it recharged OK overnight using a Sterling digital charger.
> 
> The second time it stayed resolutely dead until the supplier told me it would need to be left on charge for one week. He was right - it's fine now.


CHEERS will try a long charge with using it see if that does the trick.


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## DABurleigh (May 9, 2005)

Lawrence,

Your battery could be fine but you have a constant load on it.

Simplest way to check is with a multimeter, £5 from Maplin.

Dave


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## forterotwins (Feb 25, 2008)

DABurleigh said:


> Lawrence,
> 
> Your battery could be fine but you have a constant load on it.
> 
> ...


TELL ME MORE what am i looking for got multi meter what reading am i looking at ???
cheers dave


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## DABurleigh (May 9, 2005)

You need to connect it in ammeter mode (10A) in series between the negative and chassis. See how small (or worringly big...) it is.

Dave


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## forterotwins (Feb 25, 2008)

DABurleigh said:


> You need to connect it in ammeter mode (10A) in series between the negative and chassis. See how small (or worringly big...) it is.
> 
> Dave


Thanks Dave will have ago see i the numbers are big ???? hope not
cheers see you soon


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