Battery cable gauge

[Anonymous]

I found the cheapest source at a local automotive electrical starter/alternator overhaul shop. They sell #4 red and black welding cable by the foot and even install the ends by first crimping then soldering and finally shrink tubing the joint. the same as factory built cables. Welding cable is super flexible with a tough covering.

[wiscoboater]

Thank you Jeff Register,
I should be more clear with the boat and my layout. Due to space limitations and weight distribution/balance of the boat the battery must go in the front under the bow. The cables I was asking about would then run to the back of the boat and into the motor hood. To route them along the side up under the gunnel so they are hidden is why I end up with 11′ cables. The motor has no charging system, so the battery will need to be charged manualy from time to time. The battery it’s self is a lawn tractor battery with 300 cold cranking amps. A second set of 8 gauge cables will also come off the battery and travel the 2 feet to the bus bar and fuse block behind the dash to power LED nav lights, electric choke and the fuel gauge. I have 2 small LED lights mounted in the front and rear as well to provide lighting for the motor area and under dash area if I should at some time need to fix something in the dark out on the lake.
I bought and ran the cables yesterday. I used the Marine Cable from my local boating supply house. 6 to the motor and 8 to the accessories. The boat is a little wood race boat design, but it will just be used by my Son and myself to blast around the lake in. No competition use.

Jeff

[dave-bernard]

got pic’s of the boat??

[wiscoboater]

It’s in the current projects section. It’s titled ‘A gift for my Son"

[oldguy]

Jeff;
Lots of good ideas here, and here might be another one..Would a set of 4 gauge automotive "jumper cables" do the trick? They come 12 feet long, just change out the terminals, and you may be good to go..Just a thought..

[wyo307]

Just wanted everyones thoughts on a related subject here. How does everyone feel about using the tinned marine grade wire vs standard automotive wire? I know the marine grade will be more expensive but it should also last longer.

[Pete]

Here is DC voltage drop calculator just need to know start volts, amp draw, cable length and gauge

https://www.supercircuits.com/resources … calculator

[Tom]

Interesting calculator… try it with 3 gauge wire and see if the results make sense…

T

[Mumbles]

quote Wyo307:

Just wanted everyones thoughts on a related subject here. How does everyone feel about using the tinned marine grade wire vs standard automotive wire? I know the marine grade will be more expensive but it should also last longer.

The tinned wire is designed for marine use and while not 100% perfect, it will keep corrosion down to a minimum, especially when Liquid Tape is applied to the connections. Automotive wire will corrode around dampness and shouldn’t be used in a boat. It belongs in a vehicles dashboard, not a boats. As for the added cost, it all boils down to the ‘You can pay now, or you can pay later‘ thing. The choice is yours.

[Pete]

quote Tom Manley:

Interesting calculator… try it with 3 gauge wire and see if the results make sense…

T

Results at 3 gauge = 0, calcs probably limited to 4 gauge resistance as the largest cable in their formula

[Author]

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