# Mixing leisure batteries?



## chilly (Apr 20, 2007)

Is it correct that you can't mix and match two leisure batteries of differing makes and amp hours? (or is it hogwash :wink2

Having bought a new battery I've now discovered that it was in fact the controller that was at fault not my original battery.

So, my old battery is perfectly OK.
Just wondered whether it would be OK to use them both alongside each other :dontknow:

Older one is 100 AH. New one is 105 AH


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## raynipper (Aug 4, 2008)

Mixing is not recommended in a perfect world but will function if not to 100%.
Dissimilar batteries have dissimilar internal resistances. This will cause uneven charge and discharge. Possibly only a minor amount but as the age increases the differences become greater. Eventually in an extreme example you will end up with one fully charged and the other depleted. But thats extreme.
It just lowers the efficiency of both.

Ray.


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## Mrplodd (Mar 4, 2008)

I had two different LB’s for a good few years, never had any problems!

Andy


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## raynipper (Aug 4, 2008)

Ha ha ha. Theres always one isn't there. Like the bloke who smoked till he was 96.
It's possible your two dissimilar batteries had similar resistance Andy. Then they would work similarly.
But if you paired an old one with a new one it's likely the new one would do all the work and the old one would in fact be almost a parasite.

Ray.


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## powerplus (Oct 6, 2014)

hi ray

you are right about 1 battery working harder than the other but i would have thought once the voltages balanced out they would work in tandem

i did a similar thing a few years ago but had a switch between them so that the new battery was used most of the time but i connected the spare older battery when the new was getting a little low this did work well and once they had been on charge for a day at home i switched the spare battery off again and just topped the charge up occasionally by switching the battery back on for day

better than scrapping a perfectly good battery 


barry


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## Mrplodd (Mar 4, 2008)

Just relaying personal experience old boy! You could of course be right, or I could just have been lucky. 

Andy


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