# Reviving a dead leisure battery



## count_zer0

I put a new leisure battery in my Hymer S550 9 months ago. The van was only used a couple of times over the winter and the leisure battery seems to have drained. I have tried taking the van on a 15mile drive and this has not put any charge in it. Will it be possible to revive the battery by putting the van on hookup? Or does it need a heavy duty charger? Or is the battery toast?

I would be grateful for any advice.


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## ingram

My experience is that, if the leisure battery is flat when the engine is started, the fuse will blow, preventing the leisure battery from being charged from the engine alternator. Again, from my experience, the fuse in question is located adjacent to the leisure battery. If this fuse is blown, you will need to get some charge into the leisure battery from another source, before it will charge from the engine without blowing the fuse again.

Harvey


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## Rapide561

*Leisure battery*

Hi

I am under the impression that if a leisure battery discharges fully, it is a write off.

Russell


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## sallytrafic

First of all 15mins is not going to put much back into a leisure battery 4 hours more like it 8 hours still might not be enough (for some split charging systems.

Asothers have said a fuse could have blown be aware though that both ends of the wire may be fused.

Run your engine with a meter across your battery the voltage should show a definate rise to above 12V.



...and Russell may well be right but give it a chance first.


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## tinkering

*battery flat*

Count -zero

Take your battery out of your van,connect it to a decent battery charger, leave it on trickle charge 3-4 amps for three or four days,then check voltage, 110 amp battery 3-4 amps @24 hours +96 amps,(roughly.

Take care Les. :wink: :wink:


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## CliveMott

A lead acid battery left fully discharged for 9 months is more likely to now be an expensive door stop!

Try charging it separately as suggested but don,t be surprised if its capacity is much less than you hoped and its self leakage quite large.

C.


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## stuffed2

you may need to force some charge into the battery, as some chargers wont charge a completely flat battery. Then one of the pulse chargers may help.


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## safariboy

There used to be pills for reviving dead batteries but I have not seen them for some time and reports on them were never promising.


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## Grizzly

Read here if you want a good chuckle !

http://www.exploroz.com/Forum/Topic/25844/Reviving_Batteries.aspx

G


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## tinkering

*dead battery*

my 120 amp battery is to Bl---y heavy to shake grizzly!! 

And if you crushed up a little blue pill and put it in the battery, you might end up with a premature electroconvulsive spasm :lol: :lol:

Take care Les. :wink: :wink:


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## Grizzly

*Re: dead battery*



tinkering said:


> my 120 amp battery is to Bl---y heavy to shake grizzly!! :
> :


It's the idea of acupunture to music that appeals Les !

I guess if you're an Australian caravanner stuck with a dead battery a thousand miles from anywhere you'll try anything !

G


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## AberdeenAngus

If it's been left flat for months - it's toast.
You can waste your time trying to "recondition" it but it'll never have anything like the full capacity it should have.


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## trevorf

My CTEK 7000 5 stage charger has a 16V boost setting that is supposed to revive dead looking batteries. Never had to try it out though :wink: 

Trevor


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## Wizzo

safariboy said:


> There used to be pills for reviving dead batteries but I have not seen them for some time and reports on them were never promising.


"Bat Aid" I believe they were called. I was never convinced they did any good either!

JohnW


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## count_zer0

Apologies for the late response, I've been away for the week. Many thanks to all who responded. As a follow up, I tried to charge it on hook up for 36 hours, with no effect. From what you guys are saying, it would have been an expensive gamble (buying a heavy duty charger) to try to revive it, and I would never really have trusted the battery again. So I got a new Electrosol with a 5 yr guarantee and wrote the old one off to experience. I will definitely be taking more care to maintain it in the future! Thanks again.


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## Maraduke

*Dead Leisure Battery while on Hook-up*

We are looking for some help with a problem we are have with discharged leisure batteries. We have a 2015 Carthago i50 motorhome, it has being parked up for the last 4 months with the 240v electric hook-up connected, last week we set off for a 3 day trip away in the motorhome, when we disconnected the hook-up we found that the leisure batteries where discharged, which we thought was strange as it had constantly connected to the hook-up and the batteries should have being getting charged from the integral charger, the charger seems to be working okay as when it's hooked up all the 12v system works and the engine battery has stayed charged okay.

The leisure batteries fitted are two Exide ES900 GEL batteries fitted at the factory by Carthago, the motorhome was new March 2015 so the batteries are not quite 2 years old, we have taken the batteries out of the motorhome and tried bench charging them but they will not except charge as the voltage is too low to let the charger safety devise let them accept charge, we think as they have gone so discharged and probably need replacing, the worry is that as we dont know why they have gone flat the same problem may happen if we fit new batteries.

Something we did notice is that when we removed the batteries the battery outer cases seem to be warped as though the battery has got hot, which makes us wonder if leaving the batteries connected could have lead to them been overcharged and getting hot thus damaging the batteries which had let to them not accepting charge.

Has anybody else experienced a similar problem?


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## mike800966

Sorry to hear of the battery problem. 
I suspect that the batteries have distorted internally perhaps due to the lengthy period of charge, when this happens with old fashioned lead acid ones they self discharge and then the charger can be asked to work harder and harder to put the charge back in. I'm afraid to say that I think you should go back to the supplying dealer as I would like to be sure that the battery failure has not damaged the charger unit, even if they will not replace the batteries under warranty I would want to give them the chance to check it out to strengthen your case if something expensive, like the charger, should pack up in the future. From experience these Bloc type chargers are often around a £1000 a shot, especially if a Dealer fits it.
When batteries are really flat it is very difficult to get them to take a charge. You might have seen on other threads on here about only offering a very small charge over a long time. Even then as Clive says they will never be the same again.

Hope this helps

Mike


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