Battery Relocation Help Please

[Grippy]

nb: depending on the rules of your state, they might require you to vent the battery to atmo even if it is a dry cell/sealed (that is the case in nsw).

This is weird as the VE Crappodore has the battery under a piece of trim on the left hand side of the boot.

[newbien]

thank you everybody for your input, now i have another question....

Q. Can i run all the cables that go to the current +ve Terminal straight off the distirbution block without fuses?

I only ask because this way all my existing loom can stay and doesnt need any modification...This would be very good for me, the person who wired up my engine bay was a freaking retard and used red wiring for everything...that includes the earths...

so yeh, if i can just run the existing +ve terminal connections straight out of a distribution block that would make my life a hell of alot easier

cheers

[wagonist]

Is there a way to work out what sized cable is required?
I've heard that the longer the cable, the thicer it needs to be due to the resistance/length.

I've asking for both the rally car (battery in rear floor well) & my car (battery right up the back), as both with open up the airbox location to cold air.

[oldcorollas]

only real issue is starting.
starter is what? 1-1.5kw 100-150amps ish.

welding cable is good, as it is designed for high current, and for longer time than car batt cable

http://books.google.com.au/books?id=...sult#PPA103,M1
(scroll down a bit for the table)

and here
http://store.weldingdepot.com/pdf/weldingcable.pdf
4 gauge or 2 gauge? overkill but...

and for marine.. maybe this is better as welding cables are for higher voltage?
http://www.e-marine-inc.com/products...rs/cables.html

10-15ft, 100-150amps = 0gauge.. seems big

[wagonist]

For the rally excel, it's prob not as critical as there are only a few accesories.
Aiming to run HID spotlights & headlights to cut down on continous current used. Maybe even LED rear lights (less chance of blowing).
The only other big items are the starter motor & electric demister.

The Caldina on the other hand...
I want to stick a battery down in the rear left area under the floor storage compartment. Wasted space otherwise. Whether it's big enough to hold a battery is another question...

[oldcorollas]

starting is the only time you use very large currents
40amps of headlights <<150amp starter

how many amps you think the demister will use?

[forey]

when i baught my car it already had the battery in the boot, just not secured down and without me knowing i had taken a corner with decent speed and spilt acid everywhere . anyway cleaned all that up.
I used 6 self tapping screws in the bottom of the battery box ( making sure nothing underneath, and also a audio distrobution block in the back to join it together. i think its either 0 or 2 gauge, its VERY thick. Made it all very clean and you wouldnt know it was there under the carpet. And so much easier to wire in an amp

You can buy high AMP starter cable at places like bursons for $15 or so per Mtr

[wagonist]

starting is the only time you use very large currents
40amps of headlights <<150amp starter

how many amps you think the demister will use?

Not sure how many amps the HIDs will draw on start up, but its enough that the car needs to running.

The demister is designed to plug into a cigarette lighter (so 15A), but with the fan running & heater on high, its quite slow. I was going to hard wire it in & use a relay for the fan motor.

I'll talk to an auto lec, but I want to minimise the cable running through the middle of my rally car, there's a bit of abuse happening while the car's running. I also don't want it to fail either, so some compromise will be made.

[oldcorollas]

run thick cable in conduit and then put metal sheild underneath it (if outside car) = too easy?
surely there shouldn7t be any problem? it's nto like the car is being attacked by angry monkeys, so no compromises should need to be made (^-^)

[Mos]

Not sure how many amps the HIDs will draw on start up, but its enough that the car needs to running.

Oh? what makes you say the car needs to be running? It won't be a current thing....

The demister is designed to plug into a cigarette lighter (so 15A), but with the fan running & heater on high, its quite slow. I was going to hard wire it in & use a relay for the fan motor.

Is this the one you got from me? I don't know how much it draws, but I'd set it up on a 25A circuit...

I'll talk to an auto lec, but I want to minimise the cable running through the middle of my rally car, there's a bit of abuse happening while the car's running. I also don't want it to fail either, so some compromise will be made.

run thick cable in conduit and then put metal sheild underneath it (if outside car) = too easy?

Sorry, but that's really silly. The safest place for the cable is inside the cabin. You're far more likely to find something underneath a car, especially a rally car, that will sever the cable. If there's something inside the cabin that will sever it, you're pretty much screwed anyway.

Read this first
http://www.toymods.net/forums/showpo...8&postcount=17

Mos.

[wagonist]

Oh? what makes you say the car needs to be running? It won't be a current thing....

The battery (in the back) is a smallish odysey(?) & it couldn't power up 4 rally sized spotlights with HID globes (high wattage than normal headlight HID). Fine once the alternator has kicked in & also will stay on if they're on when the car's turned off. A lot more startup energy is required vs normal lights.

Is this the one you got from me? I don't know how much it draws, but I'd set it up on a 25A circuit...

Yes. most cigarette lighters are rated to 15A. But if the heat is on the high setting (250W vs 150W), then the fan slows down significantly.
Seeing as the battery will be in the car, going to give it a separate power feed.

Sorry, but that's really silly. The safest place for the cable is inside the cabin. You're far more likely to find something underneath a car, especially a rally car, that will sever the cable. If there's something inside the cabin that will sever it, you're pretty much screwed anyway

Yeah agree with this one
got no problem with running the cable inside the car, but there's no carpet or anything to hide it under to protect it from flying objects & big feet.

Read this first
http://www.toymods.net/forums/showpo...8&postcount=17
Mos.

Arrrgh brain freeze

OC: the compromise was more in the keeping the cable as small as possible due to less devices to run than a normal car & the shorter distance because the battery won't be right in the back vs the need to make sure it operates reliably in a harsh environment.
If the cable sizes are only marginally different, then I'm going to err on the side of caution.

[Draven]

you should be able to get some tubing around it in-cabin, and use some cable ties/p-clips/etc to fix it to the floor. If anything hits it that can cut through tubing + the plastic covering, you're probably in a lot of trouble anyway

[oldcorollas]

metal shield (if outside car) = not need thick metal shield if inside car???
angry monkeys = If there's something inside the cabin that will sever it, you're pretty much screwed anyway???

[Cuzzo]

I used 6 self tapping screws in the bottom of the battery box ( making sure nothing underneath,

Dude your going to need a better way of holding it down than that.

Also i hope the battery has its own tray not screwed in to the floor which will hold any acid leak. As it will promote rust.

[Mos]

The battery (in the back) is a smallish odysey(?) & it couldn't power up 4 rally sized spotlights with HID globes (high wattage than normal headlight HID). Fine once the alternator has kicked in & also will stay on if they're on when the car's turned off. A lot more startup energy is required vs normal lights.

That's more likely to be your battery, not the cable.... If you can't turn on a set of HIDs I can't imagine how you'll turn on a starter... (something sounds really fishy). Do you have a spec for the startup current on the HIDs?

Yes. most cigarette lighters are rated to 15A. But if the heat is on the high setting (250W vs 150W), then the fan slows down significantly.
Seeing as the battery will be in the car, going to give it a separate power feed.

"Normal" cig socket means nothing to what the heater would like to draw. If it's a true 250W you're looking at more than 20A plus fan current.

Yeah agree with this one
got no problem with running the cable inside the car, but there's no carpet or anything to hide it under to protect it from flying objects & big feet.

Are you serious? If your flying objects will sever the cable, they will sever your finger. You really are thinking of this the wrong way. Running a 4G or 2G cable with convoluted tubing over the top will be more than adequate inside of anything. If you wear through the tubing, you haven't adequately routed the cable (ie it's rubbing on something) and you will see it and can address it.

Arrrgh brain freeze

Stop brain freezing - you're an engineer, you can understand it

OC: the compromise was more in the keeping the cable as small as possible due to less devices to run than a normal car & the shorter distance because the battery won't be right in the back vs the need to make sure it operates reliably in a harsh environment.
If the cable sizes are only marginally different, then I'm going to err on the side of caution.

As small as possible!??! why?!?!
I'd want it as adequate as possible. I'd prefer to have a reliable starting conductor (ie as thick as practical) than to save a few kilos of weight.
The starting current will always be the largest draw for this sort of cable (for starters), and (secondly) "devices" are supplied by the alternator, not the battery once the engine is running, so considering the current draw of "devices" and ignoring starter current is not the appropriate method of approaching this problem.

4G will be "sufficient", 2G will be better. 3G might be a better compromise. Type of cable makes no difference - copper area is copper area is current carrying capability (in this context). Thinner strands go around bends more easily. Welding cable is double insulated (offers extra protection that strictly speaking doesn't need a tertiary protection in the cabin). Take your pick as to what you prefer.

metal shield (if outside car) = not need thick metal shield if inside car???

Oi, stop confusing the issue Metal shielded is completely unnecessary. If you're worried about it burning, fuse it. If you wear through it inside the cabin, you will wear through it outside faster. If you run it through a sill or similar, if you have a stack there you will almost definitely damage the cable.

I used 6 self tapping screws in the bottom of the battery box ( making sure nothing underneath,

Dude your going to need a better way of holding it down than that.
Also i hope the battery has its own tray not screwed in to the floor which will hold any acid leak. As it will promote rust.

Not to mention self tappers are very unlikely to hold it in an acco...

Mos.