Wire Size to Connect 2 12V Batteries?

[cruz-in]

Hi Team,

Was helping a friend clean their battery terminals and noticed her two 12 Volt batteries were paralleled with about 12 gauge wire. Seemed small to me. The coach power/ground wires are 6 gauge.

I would appreciate your input in

1) Is this a hazard?

2) What is the proper size wire for connecting two 12 volt batteries?

Thanks
Dan

[jrnymn7]

If you also use only a 10a charger.

[pianotuna]

The maximum measured draw for my RV was 276 amps. Fused at 350.

Harvey51 wrote:
The maximimum current I can draw is about ten amps, with furnace and all the LED lights on. Twelve gauge wire would be adequate.

[time2roll]

It is not just the load... what is the fuse rating?
Or does the #12 become the fuse?

[Harvey51]

The maximimum current I can draw is about ten amps, with furnace and all the LED lights on. Twelve gauge wire would be adequate.

[beemerphile1]

enblethen wrote:
I would get the ready-made battery cables. Most are #4 from your local auto parts store.

Same here, the pre-made cables are cheap and readily available.

[time2roll]

Beautiful cables made to order right here:

http://www.genuinedealz.com/custom-cables

[jrnymn7]

I used cheapo store bought ends, originally, and within one season they were rusted. So I went from 4ga with cheapo ends, to 2ga with good quality ends, and reduced voltage drop by two thirds, at 45a.

[2oldman]

..

[time2roll]

I would use #6 or better. Nothing wrong with #4 battery cables from Walmart etc. with premade ends. Connect them balanced while reassembling them.

[tenbear]

Like others have said, I rewired my battery to converter, replacing the #8 wire with #4. I did this mainly to reduce the voltage drop in the 20' or so of wire when I changed to a smart converter.

[toedtoes]

We just rewired my house battery to engine battery/alternator connection - it was about 10-12 gauge. Used 4 gauge wire throughout. Since we were adding circuit breakers into the system, I went to Battery Bill and they cut the wires to size and added all the appropriate sized lugs to each end, and heat shrinked them with the appropriate red/black colors. Cost was only $1.85 per foot.

[Sandia_Man]

X3, pre-made battery cables from virtually every auto parts store, even Walmart carries a few varieties.

[RWDIII]

enblethen wrote:
I would get the ready-made battery cables. Most are #4 from your local auto parts store.

X2

[enblethen]

I would get the ready-made battery cables. Most are #4 from your local auto parts store.