Minimum gauge size for jumper cables?

[stumpjumper1]

To jump modern 250's, what's the minimum size jumper cables that would work?

[fishnfireman]

Can't say about the "modern 250's" But I'm not sure they make one big enough to jump this 300XS..
Maybe hand built from welding cable.

[wmitch2]

10 ga is to light, 6 is ok, 4 is good for 10' or less and 2 is good for over 10'. The Harbor Freight heavy duty are ok. I think they are a 6 ga. Here's an "Old Tow Truck Trick" - use TWO sets of jumpers even on one battery to one battery and it will work much better !!

[Bill Reynolds]

This is what I prefer. This model may not be large enough for your engine but they make them for Diesel engines, should be big enough.

[fishnfireman]

I bought a NOCO GB40-- just in case !!
It also failed to start this 300XS on a cold morning.
I have since realized why, Mercury says it needs a min. of 1000 MCA and only certain batteries meet "THERE" requirements..

[DREWTICK]

If you are jumping from a trolling battery you can make a set 3 to 4ft and get by with much smaller gauge but I usually still use a minimum of 6awg on a 4ft set but 8awg would work

[Casslaw]

I agree with Bill 100% on this one. I have an Anker portable battery/jumpstarter and I have jumped multiple trucks when their old nasty 16’ jumper cables did nothing.

I walk over with this tiny little Anker, offer to help...they usually snicker, I hook it up, wait 5 seconds and I have yet for it to not work first try.

Every time the owner or the person with the cables takes a picture of it so they can get one. It’s the best $70 I’ve ever spent....except for fishing gear!

[wentbroketryingtogopro]

Can't say about the "modern 250's" But I'm not sure they make one big enough to jump this 300XS..
Maybe hand built from welding cable.

Yes welding cable is the way to go.Go to your local welding supply house and ask for #2 welding cable.They should also have your heavy duty clamps.This way you can make them any length you want.I have a set I made over 30 years ago and they are still doing the job.

[21XDC]

https://www.homedepot.com/p/Ultra-Pe...5203/301118163

[John Jackson]

Yes welding cable is the way to go.Go to your local welding supply house and ask for #2 welding cable.They should also have your heavy duty clamps.This way you can make them any length you want.I have a set I made over 30 years ago and they are still doing the job.

+2 here. I built my own from welding cable and heavy duty clamps. Cables never even get warm.

[Fish Whisperer]

I'm kind of looking forward to the next time someone asks for a jump. I just built a set from #4 welding cable. Just under 50'. I can be parked behind you, and run the cable up to your battery.

[DrewFlu33]

https://www.homedepot.com/p/Ultra-Pe...5203/301118163

Damn, if those were a few feet longer they'd be about the most economical option out there for wiring up a trolling motor.

I know, I know, only use marine tinned wire and all that.

[21XDC]

Damn, if those were a few feet longer they'd be about the most economical option out there for wiring up a trolling motor.

I know, I know, only use marine tinned wire and all that.

HD has longer and bigger wire offerings... And yes, I have used them for trolling motor cable on my winter boat.

[ScottOz]

I'm kind of looking forward to the next time someone asks for a jump. I just built a set from #4 welding cable. Just under 50'. I can be parked behind you, and run the cable up to your battery.

Wait did You say 50ft.? of 4 gauge or it cost You 50 bucks. Because if You made foot cables 4 gauge on a 12 volt circuit is only going to handle 16 amps or so. never going to turn an out board over.

[apenland01]

I got the 16' jumper cables from Harbor Freight, 6 gauge. I got the longer cables in case I needed to help out another boater in need. I believe they were $32 with a coupon.

[Triton 186]

Noco gb40

[Buck456]

Wait did You say 50ft.? of 4 gauge or it cost You 50 bucks. Because if You made foot cables 4 gauge on a 12 volt circuit is only going to handle 16 amps or so. never going to turn an out board over.

How do you figure 50' 4 gauge cables will only handle 16 amps or So? Even on a 12v system? Are you referring to the voltage drop across the length of the wire? I'm just curious how u got 16 amps.

[ScottOz]

How do you figure 50' 4 gauge cables will only handle 16 amps or So? Even on a 12v system? Are you referring to the voltage drop across the length of the wire? I'm just curious how u got 16 amps.

I am in the Auto Electric Field. I have a calculator that tells you what size wire to use for the amp draw you have. in a 12 volt circuit at 50 foot it is only good for around 16 amps. To pull 200 amps at 40 feet long you need to run 2 4/0 cables

[ScottOz]

I am in the Auto Electric Field. I have a calculator that tells you what size wire to use for the amp draw you have. in a 12 volt circuit at 50 foot it is only good for around 16 amps. To pull 200 amps at 40 feet long you need to run 2 4/0 cables

Just remember that a jumper cable is only used momentary so you can get away with more. But its going to get really hot running 50 foot. Those numbers are for continues use.

[Buck456]

I see what what you're saying. It would also make a difference if it is being jumped off just a battery or from a running boat/car. If the dead battery was able to accept a charge you could hook it up with a 4 gauge jumper cable and charge it up awhile and then see if it would start but I agree with that length of cable bigger than 4 gauge would be preferred.