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pfk avatar image
pfk asked

12v charging batteries in parallel

Hi Everyone.

I’ve got 2 x 12v 90ah batteries wired in parallel (so in theory 180ah) which I will be connecting to a 12/375 victron inverter.


I want to get a charger to charge the batteries would it be best to get a single output charger and charge them in parallel or one with 3 outputs and charge them individually?

Also what would be best to charge them 15/20 or 30amp, not worried how long it takes.

battery charging
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3 Answers
snoobler avatar image
snoobler answered ·

Not in theory, 180Ah actual.


Single charger. Attach (+) to the (+) terminal of battery 1, and attach (-) to (-) terminal of battery 2. This "spreads" the charge across both batteries. Your inverter should be connected similarly.

The cables putting your batteries in parallel should be suitable for the current you're going to pull from the bank. 375W isn't much, so 10awg is the minimum with heavier gauge providing better balance.


1 comment
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pfk avatar image pfk commented ·

That’s great, many thanks for the reply

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pfk avatar image
pfk answered ·

That’s great, thanks for your reply

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wild-thing avatar image
wild-thing answered ·

When connected in parallel, don't forget the fuse between the batteries.

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