Re: Battery in boot?
Itís pretty easy. Get hold of some welder cable (thickest stuff you can find - 30mm diameter stuff) to reach the length of the run plus some extra play. Get hold of a good quality battery box (not one of those crap cheap ones with the terminals coming out the top - connectors are too small) Youll need some decent crimp lug connectors to connect the battery and starter connections to the cable. These connections should be soldered as well if able. You will need one of those propane blow torches and heat shrink cable to cover the exposed wire after the heat has got to it. Run two lengths of the cable from the battery box to the starter motor positive connection and to the block of the motor. It is important to get a good connection at all points as any resistance could result in very poor crank power. You can get hold of a termination block of sorts to connect the 'what was" positive connections of the other wires off to the wiring harness and miscellaneous other 12V connections, and run a wire from this block to the 12v at the starter. Jaycar carry this kind of gear. They have a gold plated connector with hex grub screws in a perspex enclosure. Only thing is you have to cut the old luggs of the existing wires. Once done, it looks pretty good. Wish I had photos for examples
Another important point is the cable run underneath the car. There is several places you can get cable clamps (hardware or electrical distributors). Cable should be affixed to an area where it cannot be crushed, snagged or caught by anything. Make sure that the clamps hold the cable tightly even to prevent the metal chassis from rubbing through the insulation. Another alternative is to run the cable through the car and through the firewall. If youíre going to pass the cable through any metal, make sure you use rubber grommets so it wonít short out. This is so important! Iíve heard of these things shorting out causing the battery to explode. You canít really use fuses as the crank current is so high. In one of my older falcons, I set fire to my engine bay when the cable shorted out on the clutch cable just through years of rubbing.
Iíve been told that its a bad idea to have several earth paths (I wont bore you with those details) however I think its a good idea to connect the negative battery terminal to a good ground in the boot (good solid cable) in addition to the negative cable run. Connect a second earth in the engine bay between the block and the chassis. This is to reduce, as much as possible, the amount of voltage drop across the ground cable run so the current loading is shared between the negative cable run and the chassis.
All sounds like a big job but if your really keen, its probably worth while.
A word of note though. These batteries produce hydrogen when in use. We are supposed to have these things in a well ventilated area to vent the highly explosive gas. Iím afraid that a boot probably will not facilitate this. Some thought into this may be necessary as it could render a car un-roadworthy if inspected and even more importantly could explode!
Secondly, expect a voltage drop across the cable. This results in less power transferred to starter motor and in turn less crank voltage. It may be fine under most circumstances however on a cold winters morning when the car has been sitting there for a couple of days without being started could become cause for much frustration.
There are reasons why engineers approve of certain modifications to vehicles. The main reason is to protect you and the general public from potentially fatal accidents that are caused by such modifications.
Let me know if you have any further questions. Iím more than happy to help.