2 batteries in parallel

Hymer544

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Subject:

2 batteries in parallel

· Posted: 30.04.2014 · #1

Hi all, hoping from some advice from someone who has actually done this please:

I have two leisure batteries (same capacity) that are both charged by solar. I want to run them in parallel in a 12V system. At present one is feeding dash mounted fans and TV and the other is running everything else. I imagine its easy in theory and just a bit of wiring but personal knowlegde would be appreciated?

Thanks in advance

the fat controller

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Subject:

Re: 2 batteries in parallel

· Posted: 30.04.2014 · #2

You can join them together with a suitable sized cable, you should add a suitable sized fuse on the positive feed. Make sure both are fully charged and isolated in that there is no drain from them when connecting together, this will help prevent a spark between them on connection. Remember that parallel is positive to positive and negative to negative as the other way puts them in series and will double the voltage to 24v and dear knows what damage that will do!!!

broms

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Subject:

Re: 2 batteries in parallel

· Posted: 30.04.2014 · #3

Don't know if this will help but its how I wired mine in http://www.motts.org/second%20leisiure%20battery.htm

ABFlex

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Subject:

Re: 2 batteries in parallel

· Posted: 14.05.2014 · #4

I have found it difficult to maintain one battery over time with this configuration, both batteries feed a common 12V when joined so you will no longer have a split solution with one feeding the TV and dash fans, now both will feed everything, the only problem I have had is that the solar regulator only supplies enough power to one battery? Or so I was told!, so one battery would go low and act as a drain on the second one!
Anyway, long story boring, I plug the mains charger in once a month overnight and over the last few months all seems to be in order again,
Reading some posts on this site it would appear a good idea to use the load connections on the solar regulator to power your dash fans?
Best of luck,

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