Battery relocation - cable sizes
Battery relocation - cable sizes
I'm relocating the battery to the trunk and was wondering what size cable people had used. An "electrical minded" friend of mine suggested 25mm2 cable (not sure what that is in imperial), but it struggles as soon as the battery drops down in charge (mine sits for a couple of months between track days). Any ideas?
Cheers
Cheers
Pete K
'75 520i (track day special)
'81 M535i (dream car)
'79 323i (wife's little cruiser)
'03 320i wagon (for baby hauling)
'97 Ford Laser (1st ever new car)
'75 520i (track day special)
'81 M535i (dream car)
'79 323i (wife's little cruiser)
'03 320i wagon (for baby hauling)
'97 Ford Laser (1st ever new car)
Damn, you made me work on this one! But your friends suggestion sounds about right, maybe you could go up one size, but it seems close.
However I'm wondering, you mentioned going a couple of months without starting it, and I think that might be more the problem than the wiring. Do you actually disconnect the battery or just leave it hooked up? Is there any residuial draw like there would be with a street car, stereo, clock etc. Even the smallest drain over 2 months would be enough to drain a good battery. And if the battery isn't in great shape, 2 months would be enough to discharge it so it wouldn't start the car.
However I'm wondering, you mentioned going a couple of months without starting it, and I think that might be more the problem than the wiring. Do you actually disconnect the battery or just leave it hooked up? Is there any residuial draw like there would be with a street car, stereo, clock etc. Even the smallest drain over 2 months would be enough to drain a good battery. And if the battery isn't in great shape, 2 months would be enough to discharge it so it wouldn't start the car.
Mike W.
1980 528i, 3.5 euro, 5 speed conversion
1981 528i, 3.6, Recaros and more. Project
1998 328is, quick and efficient, but not satisfying
2000 528iit, Vacation mobile/wife's grocery getter
1980 528i, 3.5 euro, 5 speed conversion
1981 528i, 3.6, Recaros and more. Project
1998 328is, quick and efficient, but not satisfying
2000 528iit, Vacation mobile/wife's grocery getter
I think not disconnecting it was the problem. I usually do, but it's been in my garage rather than in the shed, so I've moved it every now and then. In the past, it's been OK as there's no electrics. However, I installed a GPS lap timer and it's always on when there's power (damn old fashioned cigarette lighter circuit!) and that's done it.
There's enough power to start it when I hooked it straight up at the front, I think there's just too much voltage drop in the long cable to crank it from the boot.
I've got a "trickle charger" now, so maybe I won't change the cables.
Cheers
There's enough power to start it when I hooked it straight up at the front, I think there's just too much voltage drop in the long cable to crank it from the boot.
I've got a "trickle charger" now, so maybe I won't change the cables.
Cheers
Pete K
'75 520i (track day special)
'81 M535i (dream car)
'79 323i (wife's little cruiser)
'03 320i wagon (for baby hauling)
'97 Ford Laser (1st ever new car)
'75 520i (track day special)
'81 M535i (dream car)
'79 323i (wife's little cruiser)
'03 320i wagon (for baby hauling)
'97 Ford Laser (1st ever new car)
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- Posts: 51
- Joined: Sat May 24, 2008 7:12 am
- Location: Wichita, KS
- alotawatts
- Posts: 438
- Joined: Wed Jan 07, 2009 3:52 am
- Location: Seattle WA
I have thought about it and accumulated some 6 gauge welding cable but unless you track your car (which I don't) is it really worth it ?
The rear strut brace/battery box installs look cool etc. but I would think it will be a bitch to get the battery in and out and reach for jumper cables if needed......worst being you loose cargo space for beer coolers !
thoughts ?
The rear strut brace/battery box installs look cool etc. but I would think it will be a bitch to get the battery in and out and reach for jumper cables if needed......worst being you loose cargo space for beer coolers !
thoughts ?
Three E12's and one R27
Agreed, they look cool, but I wouldn't want to lose the trunk space. Regardless, I think #6 is too small, the 25MM he's running is very close to the nearly non existant #3 in AWG sizes.alotawatts wrote:I have thought about it and accumulated some 6 gauge welding cable but unless you track your car (which I don't) is it really worth it ?
The rear strut brace/battery box installs look cool etc. but I would think it will be a bitch to get the battery in and out and reach for jumper cables if needed......worst being you loose cargo space for beer coolers !
thoughts ?
Mike W.
1980 528i, 3.5 euro, 5 speed conversion
1981 528i, 3.6, Recaros and more. Project
1998 328is, quick and efficient, but not satisfying
2000 528iit, Vacation mobile/wife's grocery getter
1980 528i, 3.5 euro, 5 speed conversion
1981 528i, 3.6, Recaros and more. Project
1998 328is, quick and efficient, but not satisfying
2000 528iit, Vacation mobile/wife's grocery getter
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- Posts: 85
- Joined: Tue Jan 06, 2009 9:12 pm
Top End Performance kit includes 4ga. cable
My kit from Top End this past summer included 4 gauge cable.
I'm trusting that it's fine!
It is Anchor brand welding cable, and measures about 9mm in O.D.
bdigel, so far I don't see the e36 jumper/junction box on RealOEM.com.
Could you point me in the right direction? I think an underhood "hard" junction point would be the "right" thing to do.
I'm trusting that it's fine!
It is Anchor brand welding cable, and measures about 9mm in O.D.
bdigel, so far I don't see the e36 jumper/junction box on RealOEM.com.
Could you point me in the right direction? I think an underhood "hard" junction point would be the "right" thing to do.
Hmmm...
Sherman
TexFest LSB&F V
95 525iT (Her DD)
92 ///M5 (????)
91 ///M5 (T donor)
88 ///M5 (Das Beast)
86 535i (Snob)
79 528i (1st 5er)
TexFest LSB&F V
95 525iT (Her DD)
92 ///M5 (????)
91 ///M5 (T donor)
88 ///M5 (Das Beast)
86 535i (Snob)
79 528i (1st 5er)
Battery Relocation Cable
I had success with an off-the-shelf ~1 metre battery cable (bought from Supercheap) running from starter motor to a cutout switch mounted in the centre console, and a standard battery cable from a 1950s Rover 90 (!) from the cutout switch to the boot (trunk) mounted battery. No problems with voltage drop, and the cutout switch (purchased from Revolution Racegear) prevents battery drain.
The Rover is a 111 inch wheelbase car with battery under rear seat. Come to think of it, my e34 Touring has the battery under the rear seat, I wonder how long that cable is...
Cheers,
The Rover is a 111 inch wheelbase car with battery under rear seat. Come to think of it, my e34 Touring has the battery under the rear seat, I wonder how long that cable is...
Cheers,
James
Hobart, Tasmania, Australia
Hobart, Tasmania, Australia