Relocating lightweight battery track use

[e30s50dan]

Working on a 318is slick top for the track. The car is pretty much rust free except for the battery box(it's bad).

Thinking of relocating the battery pc680 to the front like the cabs!

Will remove the long battery cable which is probably another 10 pounds

..my question is will it be affected by the heat? 🙄 I may try and shield the it from heat

[TobyB]

Yes, it'll die in 6 years instead of 8.

You could, instead, use aluminum wire.
I keep meaning to, but haven't.

t

[Das Delfin]

Yes it will be affected by the heat.. a heat shield would be a nice touch. Also it's important to keep a low rated CCA odyssey battery on a charger/tender when the car is parked

[lcoleman]

I think probably 70-80%, if not more, applications have the battery mounted somewhere under the hood. Heat is a concern for any battery, but AGMs are pretty resilient at the temps we're talking about. The difference in lifespan in the real world is probably measurable, but at the same time probably not worth what the actual weight difference of the wire is (I doubt it's 10 pounds though). I don't think a heat shield is worth it either.

+1 for a battery tender. The small reserve AGMs go dead quickly, and it usually kills them unless you catch it right away. That gets expensive if your car sits a lot.

[TobyB]

Hmmm, Odyssey PC625 on a race car with a kill switch, that thing holds a charge all
winter and can still fire up in the spring. Maybe the kill switch is the trick... ;)

t

[e30s50dan]

Yea,planned on a kill switch.i will weigh the cable when I get it out

[e30davie]

Why not leave it in the boot and just put it in a cheap plastic battery box behind the back seat? Screw it to the floor (making sure not to screw into fuel tank or hoses) and it wont go anywhere. You've already got the wiring to the boot, so you might as well utilise it. In my opinion anything you can get out of the engine bay (or in your case keep out of the engine bay) is a bonus, one less thing to worry about. You might want to put something else in the engine bay in that location at some stage, dunno what....but still, its a nice free space at the moment.

edit: just googled that battery, is it really that small?? tiny!! you could fit like 4 of them in the engine bay, actually might make sense to relocate it given how small it is. It is also 7kg though, the centre of the boot might be a better place to put 7kg than high up in the engine bay?

[TobyB]

...it's the weight of the wire.

Which, if you're taking out single pounds,
and many of us are, is pretty significant.

In racing, the priorities go all skew- whumpus.
Fast is everything; common sense comes second.

t

[e30davie]

haha fair enough. That means no beers or hamburgers for the driver yeah?

[Jaker]

In the E36, that battery cable weighs 6 1/2lbs. I moved my starter battery to the front and that along with the lightweight LiFePo battery that I'm using saved a grand total of 43lbs.

[Jb325is]

The car wants/needs weight back there, I would leave it in the rear. We have a small DEKA battery back there, seems alright so far.

[amcp]

I ran a 12lb battery in the front battery shelf. It saved a good bit of weight and I noticed no downsides. Didnt have any issues with the car being too loose either.

[JimmyP]

The car wants/needs weight back there, I would leave it in the rear. We have a small DEKA battery back there, seems alright so far.

^^^ This ^^^

RR is always the lightest corner on the car, leave the battery in the RR.
The factory Gruppe A cars left the battery in the RR, that should tell a tale.

[TobyB]

IF you're underweight, yes, leave battery in trunk.

IF you're overweight, tofu, 6 mile runs, no beer. And bat in front.
Bkuz yes, RR needs it, but removing weight no matter where will make you faster.
Within reason, of course...

t

[JimmyP]

If I absolutely could not put the battery in the RR of my race car, pretty much the last place I would put it would be anywhere forward of the firewall.
The couple lbs of battery cable is nothing compared to how much incrementally harder you are making it to get your static weights right, thus even harder to get the corners right.
Why make your life harder to save a couple lbs in battery cable?
You can downsize the battery cable to something like #2 (I think factory is 1Ø or 2Ø) and keep the battery in the RR or worst case in the RR passenger footwell.