Battery 2 Boot - Part 1

[Brind]

You're still going to have the same amperage on the return path too.

However since the body is negative earth you can supply the car with several routes back to the battery so you're not relying on one wire to take the heat so to speak.
Due to body panel welds and resistance through the metal I would take the 4G back to the engine bay, it wouldn't hurt! the more you can supply it the better, obviously there is a limit where it starts to make no difference but I'd rather do that than under supplying the car.

In domestic situations you will have what is called a 'ring' circuit, this is mainly used for your electric sockets.
Basically you come out of the fuse board with a cable, loop your sockets together and then the last socket is then linked back to the fuse board again.
With the two cables you can double the load capacity of the sockets.

[wirdy]

and obviously other end will connect to + on Batt, with a nice fuse!..

WITH A NICE FUSE!!!!!!

WHY?????????? It'll have to be HUGE! :wow: Like something you'd find in a national grid sub-station!!

Remember cranking your starter motor is 'virtually' a dead short to your battery - you don't need to protect this circuit with a fuse - (the manufacturers don't), your choice I suppose.

[Kieran]

Errr.....

For the benefit of Barry and people who like to meddle, would someone care to post how a battery relocation to the boot should be done?

Or have the replies to this post more or less covered it?

[wirdy]

Understand your sentiment Kieran

You beat me to it. I don't think anyone was meaning to shoot Barry's ideas down - we just wanted him to do a safe installation.
He was good enough to share his progress with us, it's just I can't stand by and watch someone do something that can be done much better - especially when a beloved VR4 could go up in flames

I think we've covered most points in this thread. The battery box question hasn't been put to bed AFAIK? I'd get one if I was doing this mod - regardless of the MOT regs .

[Kieran]

Cool

As long as all the bases are covered, that's all good in the hood :-D

/notes this thread for future reference and pencils idea into 'Cunning GLS Plans' book.... evil5:

[Brind]

This is something you do NOT want to mess about with if you're not sure what you're doing!
As Wirdy just pointed out, "could go up in flames".

One of the main misconceptions of electricity is voltage and its potential amperage.
Just because your car battery is only 12 Volts the amps in this situation is potentially 4 times HIGHER than what it supplying your house!

I don't see why a new thread should be made, the only change is the cable size.

[Japmetal]

Having done some building work on the side these pst few weeks, I may be refitting my boot with a false floor etc to take my sub box & if all goes according to plan should be relocating my battery too; When I do, I'll take some pictures, we can iron out the kinks [debates !] in the setup & I'll do a proper 'How-To" write up for you to stick in your members area


AND just for the record, that cable is fit for anywhere in your electrical system - although I'd agree that the main feed for your starter may be pushing it a bit !

[BraindG]

its all done... will show photos once the box is carpeted etc

[wirdy]

......The nyvin (ah... memories (21 years RNZAF)) type of fibreglass insulated cable is the real stuff. Very durable, small diameter for current capability, heat resistant etc. Probably difficult to source these days.......

Not difficult to source if you're still on the 'inside' Pete :boing4:

AND just for the record, that cable is fit for anywhere in your electrical system - although I'd agree that the main feed for your starter may be pushing it a bit !

I wouldn't trust it for battery cable on my car mate. It may be oil, fuel and 105c temp resistant, but it's primarily designed for audio power hook ups. If you're going to do the job properly then use proper DC power cable. You also pay a big premium for it to look nice with the clear PVC coating - but if you're putting it under the carpet- why bother? Normally these cables only go up to a maximum size of 4 gauge anyway, which isn't man enough for the current that's drawn on start-up. See cable current load for a non cable-specific guide. Barry's got it about right with zero gauge. I checked my banger car battery cable and it's 000 gauge!! :rolleyes5 Well up to the job!!

Although I admit I probably over-spec most of my cabling, just to have a safety margin of >25% of max load, I think Pete M will agree that if it's used on aircraft then that's a good indication. If they ever start using this type of clear insulated cable on aircraft then I'll drop by for dinner to eat some of your freshly cooked humble pie. :-D :-D