What gauge battery cable to relocate battery?

[Mark42]

If the battery is moved from under the splashwell to a forward location in the boat, about 10 ft of battery cable would be needed to make the run. The boat has an 85 hp Force now, and in the future will probably get a 90 hp Yamaha. I don't know the amperage draw of the starting motor, but assuming its typical for that size o/b, how can the gauge of wire be determined for the 10 ft run?


BTW, if the battery cable was run down the center of the bilge, the length needed would only be about 7 feet (as opposed to 10 ft for running the perimeter of the boat). But I'm not sure about running the cable in the bilge, even if it is bone dry 90% of the time, and when it does get wet, its just temporary. I didn't see anything in the CG regs that says not to do it.

This is the grade wire that would be used, so it is suitable for wet locations:

What do you think?

 

[JustJason]

Re: What gauge battery cable to relocate battery?

I don't see a gauge on that listing you posted, but for a 10 foot run for a low/medium size outboard i'd do 4 gauge.
You should be able to buy the cables premade anything under 12 feet, typically anything above and you have to make them yourselves.

On a side note, whenever I make battery cables for OB's or IO's (and I make a lot) I use car stereo wire, the same stuff used to hook up monster amplifiers at high end shops.
I'll use Monster cable, Stinger, Phoenix gold brand, but it's all pretty much the same stuff.
The Anchor brand cable in 4 gauge retails for close to 6 bucks a foot at places like West Marine.
I have a buddy that owns a stereo shop, he gives me scraps for nothing, perfect for short IO battery cables, or Bat to Bat connections. For what I have to pay for, I get charged a buck a foot, for 4 gauge. I mark it up to 3.75 ft.
If you cut the local marine store wire in half and cut the car stereo wire in half you'd see the stereo stuff has more strands per gauge, and had a thicker and more flexible insulator on it.
Don't get me wrong, Monster cable is overpriced on the retail end, but that Anchor brand you get is even worse considering it's quality is less.

 

[Mark42]

Re: What gauge battery cable to relocate battery?

I order marine wire from gregsmarinewiresupply.com. He has really good prices, and all the wire is tinned so there are no corrosion issues, and the jackets are water proof.

If 4AWG is what is needed, he sells it for $1.36/ft and 2AWG for $2.29/ft. and he crimps the ends on for just a few bucks.

I just wasn't sure what gauge wire to get. Thanks for the info!