Battery into boot

[Lewie]

Hey Guys,

Just a quick question about re-locating my battery to the boot. Specifically the locations I need to run cables to.

Am I correct in saying that if the battery is relocated to the boot I need to run leads:

* from Battery positive to starter motor.
* Battery negative to the body (in the boot most likely to tow bar assembly)
* Earth lead from block to body.

Am I also correct in assuming that anything currently attached to the positive battery terminal can be relocated to the starter motor where the lead from the boot will go.

The battery will be in a ventilated battery box fastened inside the boot. If I have missed any important step or any handy tips please let me know.

Thanks guys. Please add any suggestions as I'd like to knock this over tomorrow.

[dirt drifter]

yes thats correct, get the fattest leads u can find=less voltage drop.

and yeah so long as heat off the pipes wont be a hassle u can run accessories off the starter terminal

[ari666]

make sure you run an earth lead from the battery all the way to the block. so you will have two cables going from the battery to the front of the car. too much resistance from the car body and its prone to a lot of interference, so best get as many earth points as possible. from that earth lead branch off and connect as many grounding points as possible, i.e. existing earth wires in your loom, headlights, tail lights etc.

also as mentioned, the fatter the leads the better, not only for voltage drop, but also if you sit cranking the starter for a while on a cable thats too small, it can catch fire.

finally, make sure you thoroughly grommet any holes the wire has to pass through. the vibrations of driving will wobble the cables and if the positive cable is resting on something metal (like the firewall) then eventually itll rub through the insulation and short out. if it isnt fused then it will result in fire.

[Lewie]

Golden. Thanks all.

[ari666]

gotta remember that doing this mod can be pretty dangerous (fire-wise), so always overkill anything you do. bigger wire than you will need. better fuses, thicker grommets, if you use crimp connections, it doesnt hurt to put a spot of solder on them after you squish them down to make sure they dont rattle off, more tape than you need, more zip ties than you need, more everything double triple and quadriple check everything. heat shrink every soldering joint too, tape comes off, heat shrink doesnt.

the last thing you want is to get everything nice, neat and back together only to have a bit of magical smoke escape from one of your wires then have to trace the whole thing back to find the culprit.

[Lewie]

Roger. No worries. Overkill I can do.

[Lewie]

Just had a thought. I forgot to add this to the OP. Can I run both the positive and negative from the battery to the block and the starter through the same conduit or zip tied together? Or would they be better off being separated?

[Cane_It]

run your earth from thebattery negative to one of the bolts that holds the starter motor into the block.... there's your engine earth neat and out of the way.

[torch]

The body of the car will provide near zero resistance(basically 500kg of metal between) , better than any cable, providing of course you attachment points to the body are good.

Some make the mistake of just running a thick cable from the -ve of the battery to the block, this basically doubles the voltage drop at the starter that you would get if you only used the cable for the +ve. It also can create a problem for items that are earthed via the chassis/body, headlights etc, having to return via the engine block.

vb comm has chassis rails? they are an excellent point to attach to at the boot end(where the tow bar would be attached) and at the engine end.
Nothing wrong with doing the -ve to block cable as well as the boot and engine earthing attachments, apart from it consuming money.

There are many car manufacturers who place the battery at the other end of the car, all of them use the body for return path.

[Darren_L]

regarding the ventilated battery box.
make sure it's a SEALED box that has a vent tube exiting through the boot floor.

Most of the battery boxes you see around aren't sealed, which means you could end up with a boot full of hydrogen gas.....
The sealed battery boxes are a lot harder to find and more expensive, but worth it

[NPreston]

You could consider getting something like an Optima battery then you would not need to be concerned about hydrogen gas in the boot. I have one mounted in the passenger side rear footwell in a standard battery mounting tray and it passed registration and CAMS scrutineering without question. The car only has 2 seat registration, hence the battery location.

[Lewie]

I'd love to get an Optima battery actually. Bit on the $$ side though but seems to be a good investment. My father in-law has one in the Rambler Rebel he's rebuilt over the last 8 years and he has one in that. He hasn't run long enough to run in the engine yet but over all that time he's used the Optima to start it without fail over that entire period.

[NPreston]

I guess it depends on how good your existing battery is, if replacement is close an ordinary battery and sealed vented battery box may be as expensive as an Optima battery.

[iwannabusa]

i ran a 30mm cable from pos to starter, earthed to wall in boot, and ran my altinater pos to the starter terminal also, i have to earth straps from motor to body it all runs mint man.
i have 14.8 volts at the battery from the alt and thats from an old hq motor i put in my vh. i also ran my cable under the seats and thru the fire wall didnt want it under the car easy mod i reckon.