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Leisure Battery overheating need urgent advice please

Posted: 11 Aug 2020, 00:03
by JonathanR
Daughter just taken VW T25 campervan down to West Country. Arrived at midnight and phoned to say funny gas smell. Traced it to leisure battery which was very Hot to touch. She has disconnected it and put it outside and gone to bed. There is some liquid in the battery compartment.

If she goes on with journey tomorrow what do we do with the two terminals to make it safe. In that there is no battery is it safe or will there be current to the terminals either from charging from the alternator (split charge system) or the solar panel.

From memory I know there is a fuse in the positive feed from Solar panel which we can remove. There is another fuse which may be from the split charge.

I know the battery has been on its last legs but what causes the overheating? I had it on charge before the trip and noticed it was a bit hot.

Thanks for any advice.


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Leisure Battery overheating need urgent advice please

Posted: 11 Aug 2020, 01:40
by clift_d
When a vehicle battery starts failing it can offgas hydrogen sulphide (H2S) which smells of bad eggs. So the smell they noticed as they were driving was likely due to the split charge system trying to charge the dying leisure battery, and causing this gas to be given off. As H2S gas can be harmful, it sounds like they’ve done the right thing by taking out the battery.

The split charge /solar panel system will still be live and so, assuming they’re physically removing the battery, then they’ll just need to isolate the positive (red) connection so it can’t short to ground on the van bodywork, either by finding a way to isolate it through a fuse or similar, or by temporarily wrapping it in thick plastic and taping. The negative connection (black) is already tied to ground, which is effectively the van body, and so can just be tucked to one side.

Re: Leisure Battery overheating need urgent advice please

Posted: 11 Aug 2020, 06:35
by JonathanR
Thanks that’s a great help. Will isolate the live terminal, probably will wrap it as I won’t be sure it’s properly isolated with out being able to check in person, until I can find a new battery. I think the solar panel won’t know it’s there so hope it won’t start sending it a charge.


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