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Redarc wiring sizes

Posted: Thu Mar 18, 2010 5:12 pm
by nicbeer
Hey all,

Done some searching but still didnt find the answer.

Going to be running a SBI12 100A redarc on my 80 series Diesel.

2 batteres are ACDelor N70 size 95ah.

Wondering what size cable to use. from what the battery guy has suggested to use 3B&S for it all?

this enough to enable starting off the batteries in the worst case being joined?

i will be running the cable for the aux around the back of the engine bay around to the primary.

Posted: Thu Mar 18, 2010 10:26 pm
by GeneralFubashi
I have the same redarc and used 2 B&S around the back of the engine bay, has worked well. The larger the cable, the less the voltage drop for a run like this, and for a dual battery setup with this redarc, you really cant be banking on a worst case. Cause if it comes to that, you are going to have to unbolt both batteries and physically swap them over. The redarc is rated 100a continuous, and 200a spike. A starter motor will draw a lot more than that and will trip the low voltage controller in the redarc before it starts your car, mainly because your second batt will be attempting to charge your flat main at the same time as running the starter motor. Really, most dual battery controllers on the market are designed to isolate the second batt from the starter batt and not the other way around. So 3 B&S should work fine. If you are running high amps continuously from the second batt, bigger cable is a plus, just for voltage loss and voltage equalisation between the 2 batteries.

Sam

Posted: Fri Mar 19, 2010 8:22 am
by bansheebuzz
use 2b&s minimum if you intend on cranking through it, if you dont use the crank function then 8b&*s

Posted: Fri Mar 19, 2010 12:46 pm
by nicbeer
Cool cheers.

Talked to a mate last night and he can get some 95mm2 double insulated cable cheap inc lungs and that so will go for that. cant go too wrong with overkill, wont be getting any volt drop.

worst case i could swap the terminal form the redarc straight to the other batt to crank..

i'll try go for 3b&s or similar for the run up to the back to a fused distribution block

Posted: Thu Apr 01, 2010 7:59 am
by dangermowse
hi guys, what does 3b&s mean? i am tryin to do the same thing with my redarc but i know bugger all about electrics or wiring. any help greatly appreciated.

cheers, Rod

Posted: Thu Apr 01, 2010 8:42 am
by -Scott-
dangermowse wrote:hi guys, what does 3b&s mean? i am tryin to do the same thing with my redarc but i know bugger all about electrics or wiring. any help greatly appreciated.

cheers, Rod
B&S stands for Brown & Sharpe. It's a wire sizing system, which is the same as American Wire Gauge (AWG). The larger the number, the smaller the wire.

Have a look at http://en.wikipedia.org/wiki/American_wire_gauge