Correct cable size between 12v batteries in parallel.

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martin-fourie asked Mar 28, '22

Correct cable size between 12v batteries in parallel.

Hi,

Please assist with cable size required for 2x 100ah lithium batteries connected in parallel? Distance between the batteries is approximately 2meters.

The max draw in the system is a 2000w inverter that peaks at max 196amps. I’ve had a few conflicting answers.

Just need to know the size of the cable that will connect the two batteries in parallel. Also will it be advised to have a fuse between the positive terminals as well? And will it be rated at max amps drawn from the system, ie 200a, or max from one battery which is 100a?

battery connection

2 |3000

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Answer 1 · 2022-03-29T18:21:13Z

jwfrary answered · Mar 29, 2022 at 06:21 PM

Best practice would mean your batteries are as close to each other as practically possible.

The link cable needs to have as close to 0 volt drop on it as practically achievable.

It's best to bring both batteries to a buss bar with equal length cables then distribute from there, same with the negative.

Yes fuse on the battery is ideal terminal post mbrf are good and then also on the outputs from the buss bar.

120mm2 cable will yeild a 1% drop at 200 amps 12v which is OK but its much better to put the batteries phycially closer if you can.

2 |3000

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