RA28 Battery in boot?

[frag_dog]

I'm re-wiring my RA28 at the moment. The battery was in the boot before I started the re-wiring, on the right hand side, next to the fuel filler. I want to move the battery over to the left hand side and run both Positive and Negative up to the engine bay.

It seems there are 2 ways I can do it.

The first is to run the wires outside. Problem is, the wires will be running next to the exaust for a good portion of the time. An advantage is it looks like a bit more of a straight shot so I wont need as much cable (less voltage drop).

The second is to run them in side the cabbin. This way they are out of the elements and away from the exaust. Problem with this is, the wiring/aircon hole is almost full with ECU gear (3T-GTE with a Wolf), and the wiring hole thru the quarter pannel is almost full with the non-ECU wiring. Currently this is the way I'm thinking of doing it.

Has anyone done something simmilar on a RA28 or other Liftback/Hatchback and can impart some wisdom?

Thanks.

[Draven]

1. drill hole through to engine bay.
2. add rubber gromit
3. ???
4. profit

One thing to be careful of - if you have an amp in the boot, don't run your power cable next to the pre-out lines from your head unit, or you'll get distortions in your muzak.

["Z" UTE]

And you need to run the negative cable to the engine bay?

[frag_dog]

And you need to run the negative cable to the engine bay?

Well I was having some electrical issues before I started re-wiring that may or may not have had to do with the negitive. The previous wiring had the negative connected to a bolt that was tack welded to a bit of the boot floor pan. If I have the neg connected straight to the block, that should give me plenty of crank.....

1. drill hole through to engine bay.
2. add rubber gromit
3. ???
4. profit

One thing to be careful of - if you have an amp in the boot, don't run your power cable next to the pre-out lines from your head unit, or you'll get distortions in your muzak.

Are you allowed to put holes in the firewall without getting a mod plate or something?

[Hash_ra23]

theres a grommeted hole in the firewall which comes out on the passenger side you can run your cable thru. You should also put a circuit breaker on your battery when relocating it to the boot.

[frag_dog]

theres a grommeted hole in the firewall which comes out on the passenger side you can run your cable thru. You should also put a circuit breaker on your battery when relocating it to the boot.

If your talking about the tilted oval hole, that has my ECU wired thru it.

I'm going to get something in the order of a 200Amp CB off the positive terminal.

[o_man_ra23]

Circuit breaker is a good idea, but a massive fuse is better. They have a higher fault current rating.

What size cables do you intend on running?? Putting an earth to the block directly is a good idea, but you should also earth directly to the body (find an OEM bolt which bolts to the body and use that).

Running the cables under the body is a recipe for disaster IMO, the heat, oils, dirt, water and other contaminents will degrade your cable insulation. Best to run it in the channels inside the car. Also you need to think about how you are going to seal the battery. An unsealed battery in the boot will not pass an engineering inspection, and is grounds for the popo to issue with an $80 defect, and take your car off the road till it is rectified. It may also be a copout for an insurance company in the event of an accident.

Make sure the battery is firmly secured. What do you intend on securing it to??

Cheers, Owen

[Hash_ra23]

If your talking about the tilted oval hole, that has my ECU wired thru it.

I'm going to get something in the order of a 200Amp CB off the positive terminal.

yeah that hole..i put my ecu wiring and the battery cable thru there.

[TheToyman75]

Frag Dog,

There is no reason you should need to run your earth cable all the way up to the front of the car. I suggest using one of the rear bumber bar mounting bolt locations. From memory thats what I used. I do suggest using the biggest cable you can get your hands on. I went with 300amp welding cable from a local welding supply company and also used the same welding cable for the earth strap from my block to the chassis at the front.

I chose to run may cabling in the cabin. Both cables exit the battery box through grommetted holes in the base and into the false floor area. remember to run a constant power feed for your stereo, clock and ecu if your installing a battery cut off switch as part of the install. The cabling is not obvious under the carpet and is obviously more protected in the cabin space than under the car. From memory there is a hole in the firewall right near the starter motor, i think it was for the a/c drain hose. My power cable comes straight through there and to the starter motor. The Alternator also meets up there.

You can fit a battery jump start post into your engine bay quite easily but using a cotton real mount as the junction for the power cable in your engine bay.





I hope that helps.

[Smokey228]

I need to put a fuse, how do i measure the maximum amps that my car requires to run though? And do i just up that say a few amps and then buy that sized fuse?

Cheers,
Jase

[Draven]

Fuse - generally, as big as possible. A short will cause a HUGE surge which will blow almost any fuse. Any other electrical fault should be taken care of further down the line in a fuse box. I think I ran a 250A fuse (from the recesses of my memory, years ago) - it was the biggest that All About 12V had in stock (highly recommended by the way, for crimping, cutting, etc).

Bear in mind Rod's setup (above) is not technically legal - those marine boxes aren't totally sealed. I ran the same setup in my old ma61 hatch, but an anal person (or HWY patrol officer) may not agree with the arguemnts offered. You'll need a tray, a drain hole (for spillage/overflow, gromited to outside the car).

As noted in Rod's setup, as well as the pretty nylon strap, make sure to fit a proper batter clamp secured to the metal floor if you want to avoid a very heavy lead-acid bomb bouncing around the cabin in the event of an accident.

I ran 2 fuses mounted to the side of my battery box - 1 for my boot mounted amp, 1 for everything else. a 0-guage wire to the chassis as an earth strap should be plenty, as long as your earths in the engine bay are up to scratch. 2 or 4 guage power cable to the engine bay will see you through. As Rod mentioned, earth to engine bay is unnecessary (imho).

[TheToyman75]

Greg,

Technically your right battery boxes are supposed to be sealed to meet the letter of the law. You would have to be very unlucky to get done tho as any enginner I have delt with is more than happy with a marine box as available from any automotive parts supply store.


If you run a lead/acid battery you have to have a breather to outside the car. Because I run the gell cell battery I don't need to have this

As for the mounting of the box - Technically the box itself needs to be secured to the floor (I used mup guard washers under the M6 S/S cap bolts) and yes the battery must be secured. Those nylon straps are only to keep the lid on the box. Even if your engineer or blue slip inspoector doesn't check your battery mounting the guys at WSID will so make sure its secure if you intend to race.

And as Greg said the last thing you need is a few kilo's of battery remodelling you or your passengers in the event of an accident.

[Smokey228]

I thinks i need to run a bigger earth cable from my battery, and i need to get a big ass fuse, and i deffinetly need to mount my battery better, atm its cabled down as i cant fit a clamp into the box, as i got the biggest battery available from NRMA

Are those cargo straps okay for holding the battery down? The ones that are spec'd upto 15kgs etc..? I was thinking, i could bolt a metal plate down underneath the battery, (this holds the box down through the floor) and then have a elevated section so the strap can go underneath it... Use the 15kg strap over the battery inside the box, and the normal nylon strap over the lid to hold the box?

Cheers,
Jase

[Toy77]

Hey guys,

Like Rod, i used welding cable for my battery cables - heaps cheaper than auto cable too. and it has massive insulation - mine has 2 different layers.

My engineer up here wouldnt accept a marine box as suitably vented - BUT i have a euro style battery - very compact, low mounting post etc - but it has a breather line from the top of the battery.

ie the battery is sealed and breathes through a small tube - which i routed out the bottom of the box - through the floor. engineer was happy with this.

This is a cheaper alternative to a gel sealed battery (which i will be using next time anyway) - this battery my uncle was able to source for me at under $100 and is over 500cca from memory.

cheers
Stew

[thomasbl]

I ran my 28 battery inside the cabin.

There is a hole in the firewall, with a perfect sized grommet already attached down near the chassis rail on mine. Its below the one you are using for your wiring.

I connected the earth to part of the frame, near the battery to save length of cable running through the car and i didn't see that it was nessecary.

My 1G works fine like this. I did attach a better earth cable from engine and gearbox to chassis though.

I included a circuit braker in case the cable got pinched in an accident.