guage For battery cable

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

Get the exact length, correct lug, pro crimped and sealed up with shrink wrap.
#8 to 4/0 at a good price.

Thanks for your responses. I ended buying the 1 gauge. So far so good

As long as you're not pulling more than 30A then you're fine, but I bet I could suck alot more than 30A at peak out of my camper batteries without trying too hard. That's a small fuse depending on your setup.

Interesting topic. 2 or 4 gauge wire, but I am supposed to have a 30 amp fuse in line and the wire attached to the fuse holder is 8 gauge at best.

wa8yxm wrote:
The answer depends on the max Current. For up to 100 amps 4GA is ok, but 2GA is better. if you are planing on drawing 200 amps. Now we are into 0000 land.

What he said^. And at that you could probably get away with 6ga, but I’d have to calc the amp draw, 4 is safe.
2/0 is not even remotely applicable for a couple deep cycle camper batteries unless you’re trying to arc weld with them!

http://www.smartgauge.co.uk/batt_con.html
I have two 12V AGM on my TT
Balance is key to making them last

The answer depends on the max Current. For up to 100 amps 4GA is ok, but 2GA is better. if you are planing on drawing 200 amps. Now we are into 0000 land.

I stand corrected. Thank you.

Optimistic Paranoid wrote:

DrewE wrote:

In theory, the cables between the two batteries only carry half the current that the cables to the inverter would carry (assuming two batteries in parallel) and are short enough that added voltage drop is fairly insignificant.

Well, yes, that's true IF you hook your + and - wires from the inverter up to the SAME battery. Personally, I would hook the + wire to one battery and the - wire to the OTHER battery to keep the load on the two batteries balanced. For that, you want the battery to battery cables to be the same size as the inverter wires.

In that case, it still works out that each interconnect would carry half the current (the half going to or coming from the "other" battery from the connection to the inverter) assuming they are operating in a balanced manner. As I did write, in a fault condition like an open battery, they could have to carry the full current regardless so they should be sized at a minimum to do that safely (without catching fire), but presumably one doesn't care about e.g. voltage drop in a fault condition.

thehippie wrote:
putting a heavier gauge is ok?

Sure. Won't hurt a thing. Well, unless you go RIDICULOUSLY overboard, in which case the only thing you're hurting is your wallet . . .