EAtDUST

Need some advice for relocating my battery to the boot.

I already have the battery box and i have 2gauge cable running through the car to the boot for my stereo and it's rated at 200amp. I also have all the distribution blocks to suit this cable and 4gauge cable . My alternator is 100amp. My stere/amplifiers draw 70amps-max. Amps have 1x50amp fuse and 1x 20amp fuse in the rear distribution block. There is a 60amp inline fuse in the engine bay.

For the relocation (due to turbo) i'm thinking of connecting the distibution block to the fusible links/starter power (all positive wires) in the engine bay and running them to my inline fuse on the firewall. The 2gauge would run from the block , to the fuse , through the firewall , under carpet , to another inline fuse in the boot and then to the battery box..................................
1) What rated fuses should i have in each holder (boot and engine bay)?
2) Is the cable strong enough?

I was going to ground the battery in the boot and then join all the neg leads in the engine bay together and ground them to the chassis in the engine bay.

My stereo would then run off an individually fused distribution block in the boot connected staight to the battery using 2gauge and dropping to 4gauge out the other end of the block to each amp. I'll be getting a suitable optima for the job.

PHEW! i'm outta breath just writing that.
Is this a viable setup. I already have a lot of cabling which ain't cheap so i'd rather not have to go and buy thicker cable or pull out the car interior again.

EAtDUST

Anyone??

351cid

i will have a go.

your earths will be fine if you make a good conection to the body in the boot with a decent size lead.
have a heavy duty lead from the engine block to the body at the front.

i am not quite sure of the wire size measured by gauge , but in mm2 , you would be looking for at least 50 or 70 mm2 to use as a main power feed to the front/ starter.
this is like the size cable that would is used on heavy duty electric arc welders.
its not normally run through fuses , you would need a pretty big fuse, have to test the load on the main battery lead with everything opperating at total max, starter , lights , fans , everything that uses power to see what size fuse.
i think that most people would just have a battery isolating switch .

__________________
dave
`75 XB FAIRMONT SEDAN injected 351, toplaoder, disc brake 9", factory paint+ vinyl roof.
`03 BA XLS ute - lpg, auto, lsd, acid rush paint,
WWW.sunshield.biz

AGRO XR

EatDust.
Whenever you run cable of any sort, there are a few things to consider.
1st: The maximum load to be carried by the cable in amps.
2nd: The length run of the cable.

You might have 200amp cable, but this value(amps) will be less the further your length of cable is. If it's automotive cable (200amps), I would think that this would be for no more than say 2 meters of length. So, if your length from engine bay to boot is say 5 meters, this cable then de-rates it's permissible load by say about 50amps continuous. The cable will now only be rated at say 150amps.
In my view, a good indication to see if your cable is big enough (for its total length & load), is to load it to your desired amps(max), and see if the cable begins to get hot. If it does so within say under 30 sec, the cable is not big enough. The hotter the cable gets, the more it begins to draw in amps, even with the same load applied.

Your fuses.
The one in your boot, is to protect the cable over it length run.
This size fuse can't be greater than the rated amps of the cable....installed. If you take the above explanation, and your cable is calculated to be 150amps, your fuse should not be larger than 150amps.

The in-line fuse under your bonnet is to protect all your accessories running from the distribution block. This should always be smaller than the above fuse, but about your max Amps to be drawn.
Example:
Head lights/driving lights 20A
Stereo with amps 70A
Heater on 10A
General accessories 10A

Total 110Amps.

So this fuse will be around 110Amps, BUT NO GREATER THAN 150A.
If this calculated load exceeds 150amps as in the above example, you need larger cable.
You will find the largest load will be the starter motor, but you shouldn't have your stereo blasting at the time of starting your engine, otherwise, you will need more than a 200amp rated cable I would think.
Hope I have been clear enough.

Regards

AGRO.

351cid

if you can feel the cable getting warm at all , it is too small.

if the cable is too small , you will find that you will start having all kinds of problems.
from hard to start to worst case ... a car on fire.

__________________
dave
`75 XB FAIRMONT SEDAN injected 351, toplaoder, disc brake 9", factory paint+ vinyl roof.
`03 BA XLS ute - lpg, auto, lsd, acid rush paint,
WWW.sunshield.biz

EAtDUST

I just went out and grabbed a 150amp AML style fuse and fuse holder which i'm fitting to the boot end of the cable then to the battery +. I'm then gonna fit a fused distribution block to the engine bay and run my accessory positives to the fuses but run the starter cable directly into the main cable unfused so it gets full voltage.

Anyone one know what the fusible links are rated at so i know what amp fuse to get to match?

AGRO XR

If you have a manual of the electrical of your car, they usually tell you the rating of this fusible link. I cant help you off the top of my head though!!

Regards

AGRO.

EAtDUST

I have 2 different workshop manuals and neither of them tell me. I'll give ford a buzz.