(Battery in boot) What gauge wire is best?

[BUGEYD]

Hey wanting to put battery in my boot just wanting to know what gauge wire is good (safest) to use? Is 4 gauge good theres a battery in boot kit on trademe with 4g.

Cheers
Kyle

[neo]

Ive done all my cars with 4G, some people use 0G but thats massive + can be a PITA getting adapters for.

With 4G I still see 13.8v when the alternator is charging at the battery

[frost]

search: its been coved many times, double shielded welding wire..

[Burning Angel]

yea 4 gauge should be fine you should only drop to ~ 10v on cranking thats assuming 100amps draw

im putting mine on the floor behind the seats but havnt actually done it yet

[gepsk8]

lol, i wouldn't put 4gauge(its for stero's!!) in if u paid me to do it, its more to do with current than voltage when it comes to starting, i would use 35mm welding cable with double shielded at min, on 2litre less sort of thing. 50mm on anything bigger. with a switch for safety.
what happens if the battery little flat take more current to start the car, or starter on its way out? 4gauge cable gets hots with high current draw from amps let alone starting as with no fuse could cause a fire if shielding falling off with the heat.
when batterys mounted in front less than 1.5metre from starter they get away with lighter battery cables. longer the cable more voltage drop.
also look at ur earths as current flow from negative to postive, (techically speaking) would up grade them to the size cable u use, on battery to earth and engine to earth.

[Lloyd]

Personally I'd say 4ga is a bit borderline. Go slightly bigger if you can but you should be able to get away with using it if you have to. As above, welding wire isn't that expensive and you can get it pretty decent size. Used 2 runs of 4ga myself in the Levin as I didn't want to trust a single. Look at getting a decent size fuse to put at the battery or a decent circuit breaker too

[gepsk8]

thats the thing u cant put a fuse for the battery cable to starter, cause it draws to much current, biggest ever car fuse i've seen is 425amps, which might work in good conditions but would blown as soon as u got a cold start or flatish battery.

[bubz]

I am using double insulated 12mm copper only, welding cable in my GTT.$40.00/metre.Overall cable thickness(copper + insulation)is around 18mm.

Let me know if you like the price of the cable,I'll see if I can hook you up some.Six metres should be fine,including the Earth.

[gepsk8]

sounds way to expensive, i can get it but in 10m rolls about $15/1m last time i checked or something silly.

[ChaosAD]

12mm dia? or cross section?

[bubz]

diametre

[QikStarlie]

$40/m sh!t, was about that much for 6m last time i got some. that was for either 25mm2 or 35mm2 stuff. double insulated ugly orange stuff.

find someone with a trade acount at an electrical wholesalers, like ideal, ja russel etc. retail at those places are a total rip.

[postfach]

i have a trade account at corys electrical.


i did this with 25mm² double insulated flexible "welding" cable and i have had no problems with the wire heating up or starting the car, if anything it works better than the factory cable. only trouble i ever had was my earth wasn't quite up to scratch and the car randomly didn't want to start one day. moved it to a better place and it's been fine ever since.

[Crampy]

4GA Raychem Mil spec wiring. Free from work hehehe

[BUGEYD]

i have a trade account at corys electrical.


i did this with 25mm² double insulated flexible "welding" cable and i have had no problems with the wire heating up or starting the car, if anything it works better than the factory cable. only trouble i ever had was my earth wasn't quite up to scratch and the car randomly didn't want to start one day. moved it to a better place and it's been fine ever since.

Sweet might give that ago whats the pricing on that stuff? I got a mate whos a sparky so ill go through him cheers for the info!

[postfach]

Sweet might give that ago whats the pricing on that stuff? I got a mate whos a sparky so ill go through him cheers for the info!

not sure what it costs sorry, i got mine free from work so i never had to buy any. cable usually costs more than you would expect but with discount it won't be so bad, blame china for using so much copper and pushing the price up

[Calvin]

4GA Raychem Mil spec wiring. Free from work hehehe

Hook me up

[Stealer Of Souls]

lol, i wouldn't put 4gauge(its for stero's!!) in if u paid me to do it, its more to do with current than voltage when it comes to starting, i would use 35mm welding cable with double shielded at min, on 2litre less sort of thing. 50mm on anything bigger.

I might be mistaken...
But 4ga is approximately the same as 35mm...

Oh.. and as my 2c
4ga would probably be okay for the connection to the exisiting wiring (current +ve terminal, but less the starter wire). But I would replace the cabling to the starter with something bigger than that. 2x4ga, 2ga, notice that starters are always wired directly to the battery via a dedicated cable. Anything else that draws big current would probably benefit from being wired directly to the battery via a dedicated feed.
And for safety's sake. Use fuses, or breakers on every wire except the starter line. Put the fuse/breaker within 30cms of the battery.
Basically. Follow the same basic layout as the factory wiring system but with bigger cable. Can't really go wrong.

[neo]

thats the thing u cant put a fuse for the battery cable to starter, cause it draws to much current, biggest ever car fuse i've seen is 425amps, which might work in good conditions but would blown as soon as u got a cold start or flatish battery.

Dude your doing something wrong.

I have a 120amp circuit breaker on the 4ga lead coming off the battery in the racecar and it doesnt trip. Hell I had an 80amp circuit breaker on the bettery in my old mini which had a direct drive starter and that never blew either.

Just ensure your using good quality oxy free cable , and remember to match it with the earths / grouding points!

[Lloyd]

Likewise here, 140A breaker on the starter and it never tripped.