Battery to boot - what do I need?

GeX · 29 Jan 2008 at 12:44

don't be so sure, car manufactures do get it wrong. my house mates mk2 golf gti caught fire because the feed to the headlight switch is unfused from the battery / loom. exactly how VW left it.

i moved my battery to the boot, and the cable is fused at the battery end.

other forum? that'll be rovertech then

i remember the thread

Simon · 29 Jan 2008 at 12:58

agw_01 said:
BMW's were one manufacturer I was thinking of.

They lay the cable while building the car though so obviously route it in the best place.

Laying a cable through your car on your own, having to go over and under things could result in the cable chaffing... no matter how well you run the cable, I'd rather not risk it.

I really really can't believe there are people disputing the use of a fuse on a high current cable. This happened on another forum, I really thought you guys would have a bit more sense

As Dogbreath says there is no need to fuse it. Mine was fine for 5 years on my Rover, you have only earthed the battery end, the alternator will still be shorting out the other half if it was to chaff (no idea how when it's under the carpet and you obviously avoid sharp edges). I used welding wire, the same stuff that gets dragged around the concrete floor of most industrial units daily withoug wearing through.

It's really not an issue. Kind of ironic though, you're driving around in a car with a leaking petrol tank!

Simon · 29 Jan 2008 at 13:01

OllyM said:
I don't think my car has a fuse between the battery (which is in the boot) and the starter motor, and BMW surely know what they're doing when building cars

If it was dangerous, they wouldn't do it without a fuse would they?!

Nope, and in cold weather a fuse will keep blowing anyway. Kind of handy when your stuck out in the middle of no where and you've used your last fuse

Worst that is going to happen is the battery overheats. The current draw from a battery with the engine running is quite low.

Dogbreath · 29 Jan 2008 at 13:27

agw_01 said:
I really really can't believe there are people disputing the use of a fuse on a high current cable. This happened on another forum, I really thought you guys would have a bit more sense

Ask yourself why two forums worth of people have disputed this....

The bottom line is that a fuse is undesirable for several reasons, and if the cable is installed properly there should be absolutely no need for it.

GeX · 29 Jan 2008 at 13:41

Simon said:
The current draw from a battery with the engine running is quite low.

that's completely academic. if you short out a battery it'll dump as much current as it can through the short, do it with the engine running and it'll draw max current from the battery and the max it can out of the alternator too.

Simon · 29 Jan 2008 at 13:45

GeX said:
that's completely academic. if you short out a battery it'll dump as much current as it can through the short, do it with the engine running and it'll draw max current from the battery and the max it can out of the alternator too.

Point is that agw is making out the cable is special as it is high current. Any cable is high current if you ask it to be

To be honest 4wg is too thin IMO.

GeX · 29 Jan 2008 at 14:32

i think his point was that it has the potential to be carrying high current, yes - in normal situations, with the engine running there will be little current across it (unless cranking) but if you were short that cable to ground, then you'd have a direct short across the battery which is going to heat up the weakest link (which is meant to be a fuse).

i don't know what the awg is of my cable is (i'm not american) but it is rated at 194/0.40 25mm2, 9.8mm OD, 170A, and the wiring is fused at 150A. The fuse protects the wiring

Simon · 29 Jan 2008 at 14:39

170A isn't really enough on some engines, especially on cold days with old thick oil. Shouldn't be a problem on yours though as its a small engine.

GeX · 29 Jan 2008 at 14:42

indeedy, it lets me turn the engine over at around 400rpm on the starter.

i don't know what size engine the OPs 205 has though

-westy- · 29 Jan 2008 at 19:55

GeX said:
indeedy, it lets me turn the engine over at around 400rpm on the starter.

i don't know what size engine the OPs 205 has though

its a 1905cc XU series PSA engine

Lopéz · 29 Jan 2008 at 21:45

No fuse. Box in boot. Earth it in the boot somewhere. Use a GOOD gromet or a bulkhead connector like Penski mentioned.

When you get to the engine bay you need 2 big lives.

1 goes to the "shunt box" (where your loom gets all its power)

The other goes to the starter

This is the connector I used at the bulkhead:

-westy- · 29 Jan 2008 at 23:48

Lopéz said:
No fuse. Box in boot. Earth it in the boot somewhere. Use a GOOD gromet or a bulkhead connector like Penski mentioned.

When you get to the engine bay you need 2 big lives.

1 goes to the "shunt box" (where your loom gets all its power)
http://ukrm.org/lopez/car/28.jpg[img]

The other goes to the starter

This is the connector I used at the bulkhead:

[img]http://ukrm.org/lopez/car/32.jpg

Can I connect one live up to the shunt box, then run a cable in series to the starter? or is that likely to blow stuff up? Would it be easier just to chop the terminal off the positive lead (bay end) and stick on a distribution block, running the cable to the battery in the boot?

Where have you earthed your battery Leon? and Where can I get that bulkhead connector from? Where did you run the lead through the bulkhead?

Apologies again for all the questions

agw_01 · 29 Jan 2008 at 23:54

Dogbreath said:
The bottom line is that a fuse is undesirable for several reasons, and if the cable is installed properly there should be absolutely no need for it.

Fair enough

I guess it's just down to personal choice.

Lopéz · 29 Jan 2008 at 23:54

-westy- said:
Can I connect one live up to the shunt box, then run a cable in series to the starter?

Can't see why not, the shunt box is a handy place to take live feeds from though so 2 big ring connectors on there was a no no for me

Would it be easier just to chop the terminal off the positive lead (bay end) and stick on a distribution block, running the cable to the battery in the boot?

Could do - mine fell off at the connection by the shunt box anyway so I just thought sod it and ran a new whole cable.

Where have you earthed your battery Leon?

In the boot, just above the rear arch, there's one of those big gold bolts, think it's for the rear seatbelt? Seems to work fine anyway

and Where can I get that bulkhead connector from? Where did you run the lead through the bulkhead

I think I got it from www.autosparks.co.uk

Mounted it where the steering column goes on LHD 205s

-westy- · 30 Jan 2008 at 00:20

Arse, unfortunately I don't have the luxury of an empty engine bay to work with! Any other suggested points to run a grommet through?

Lopéz · 30 Jan 2008 at 00:21

-westy- said:
Arse, unfortunately I don't have the luxury of an empty engine bay to work with! Any other suggested points to run a grommet through?

I installed it with the engine in the car - just drill through from the inside (it's about where the carpet stops in the footwell)

Phil W · 30 Jan 2008 at 08:55

My friend has just done a bsttery relocation on his Evo 5. For some really obscure reason, he used an ICE powerlead.

And yes.. they really are ICE leads...

agw_01 · 30 Jan 2008 at 12:54

Nothing wrong with that

I'm using cable, fuse holders and distribution blocks designed for car audio installations.

If the cable meets the spec required, there are no real problems.