Battery cabling. (1 Viewer)

[bad_religion_au]

I'm relocating the battery to the back of my rig, i was wondering what thickness cable i should use to minimise resistance/ power loss due to the increased distance.

In particular i want to make sure my starter gets enough current.

 

[Eshu Elegua]

i will said 2/0 welding cable..that will handle the engine and winch easy and worry free....

 

[bad_religion_au]

should have mentioned, only needs to start the motor/run the lights and ignition system. not even a stereo in there. winch is PTO, not electric, so that is a concern eliminated.

was going to run welding cable. that stuff is nice to work with

 

[Coolerman]

Disclaimer: The following suggestions are for the ideal wiring of a remote battery. I know, everyone knows someone who wired a battery 30 feet away with 12 ga wire and it worked fine....

Are you running a stock motor and starter? If so a stock F (non-gear reduction) starter will pull a bit less than 240 amps when starting. A 2/0 cable will carry that amount of current with a 2% loss of power for 12 feet. A 3/0 cable will go 15 feet. A 4/0 will go 19 feet.

You can run longer runs of smaller cable, but at a higher loss of power. Loss of power equals heat in the cables, and loss of energy to the starter, which equals slower cranking speeds.

Also be aware that remote battery locations will need to have the regulator/alternator wires run to the battery. Why? This will ensure the regulator is getting an accurate voltage reading from the battery, taking into account the voltage drop across the long wires. Don't forget to increase their size to compensate for the longer run, especially the alternator charge wire. An OEM wire is 10ga. If you have a 50 amp alternator and need to extend the wire an addition 12 feet you should up the wire size to 6 ga.

Protect all the cable with some form of covering. These wires will be exposed to day to day hazards that under hood wires will never face. I don't have to tell you the consequence of shorting a 2/0 cable to ground with no fuse.... Think welder....

 

[bad_religion_au]

Cheers for that Coolerman. it's a ford 250ci straight 6 (similar to crank as a 3fe) and it runs a gear reduction starter (the starter off the later 2f's). any idea on the amps that sucka pulls?

Cable will be tucked up well out of the way, and sheethed with whatever i can find to fit it. don't worry... i... respect i think is the word, the dangers associated with big current/big cable installs.

 

[Coolerman]

Cheers for that Coolerman. it's a ford 250ci straight 6 (similar to crank as a 3fe) and it runs a gear reduction starter (the starter off the later 2f's). any idea on the amps that sucka pulls?

Cable will be tucked up well out of the way, and sheethed with whatever i can find to fit it. don't worry... i... respect i think is the word, the dangers associated with big current/big cable installs.

No, I don't know what a 2F gear reduction pulls when cranking, but I would like to.

Can someone with a 2F manual that has the gear reductio starter look in the engine section and see what the amp pull is?

 

[flaminbandit]

4 gauge is what i used for that exact startermotor

 

[Trollhole]

Do you have a winch or plan to have one? I'd stick with 2/0

 

[TOBASH]

Go for biggest wires you can find. Spare no expense

Then ground batteries to car frame, not to another long wire.

I am big on 2-0 and larger. I also am big on fluxing the wire tips, properly crimping copper leads, and then braising/soldering battery clamps and end fittings to the wires, followed by shrinkable tubing to keep air and water out.

I have never had an issue.

As far as attachment, I attach the positive lead wire to the starter solenoid and not to the factory positive wire in all the cars I move batteries on. I have NEVER had an issue. If you are worried, you can attach a separate wire from the solenoid to the fusible link.

Best,

T

 

[bad_religion_au]

Do you have a winch or plan to have one? I'd stick with 2/0

no plans on getting an electric winch. the PTO will do me fine for a long time

 

[bad_religion_au]

70mm2 welding cable is sitting on my living room floor ATM. that's ~ 2/0 guage i've been told. over 9 feet, i can't see my power loss being worth worrying about

now i gotta work out the best way to do these lugs.

 

[Coolerman]

70mm2 welding cable is sitting on my living room floor ATM. that's ~ 2/0 guage i've been told. over 9 feet, i can't see my power loss being worth worrying about

now i gotta work out the best way to do these lugs.

Yep, no problem with 2/0 and 9 feet . 2/0 is good for 250 amps at 12 feet.

 

[Trollhole]

Solder slugs and a hammer crimper along with some good heat shrink tubing.