# Leisure battery drain issue



## Waleem (Nov 1, 2006)

Guys
We returned from a weekend away last week to discover that the leisure batteries (two 85AH) barely had enough power to work the step-despite being on hookup all weekend and driving 60 miles home. Plugged the van in, and the batteries recharged to full again at a normal rate. However, when I disconnected the hookup, they discharged again overnight.

As the batteries are 5 years old, I suspected that they needed replacement, but seeing as they will cost me over £100 the pair, I thought I would do a couple more experiments first. I noticed the fridge was still switched to 12V, and I have heard of relays sticking to allow 12V to continue to work with the engine off, so I switched it off. The drain continues. Then, I tried the simplest thing of all....turned off the habitation 12V supply at the switch.  Result is the drain seems to have stopped... :? 

Now if this is the case, am I right in thinking that something somewhere is drawing power when it shouldn't be? If so, I can't find out what-all lights, pump etc are individually switched off. Does anyone have any ideas as to what the problem might be?

(I should add that the engine battery seems completely unaffected by this even though they all charge through the inbuilt charger unit when on hookup.)

Many thanks for your advice.


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## rosalan (Aug 24, 2009)

Did the batteries discharge with the motorhome master light switch off?
I recently had the same problem and convinced the batteries were at fault, I went to our local Motorfactors (who sell leisure batteries) to test them. They both were fine, so biting a bullet I went to an auto electrician who found several reasons for the discharge including poor relay connections and some minor earthing issues. He was marginally cheaper than two batteries but fixed the problems. Had I replaced the batteries I would still have had the discharge and still need an auto-electrician to sort it out.
Good luck!


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## CliveMott (Mar 10, 2008)

Before you purchase any batteries you need to check a few things, you may just have a bad connection somewhere. Check that all the battery connections are clean and sound, best to remove them and re-make them to be sure.

Are these batteries the top uppable type? if so when did you last check that the electrolyte is about 3mm above the top of the plates?.

Check the battery in-line fuses. Its not unusual for these to corrode in the fuseholder. Take them apart to check and if necessary replace both fuses and holders.

Check by removing one at a time the DC connectors on your control box. (not the panel you look at but that lump burried in a cupboard or under the bed!)

Check the battery terminal voltage with an independant digital voltmeter. You should see under all forms of charge close to 14 volts.

Check with the solar panel covered up with a sheet of cardboard.

a Just engine running.
b just on hookup.

My guess is that by now you will have found your problem. as a bad connection.

C.


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