Battery Relocation
So, why bother moving your battery from the engine bay? Perhaps you are:
- Going for the decluttered/clean look so want it out of sight
- Fitting a front mount intercooler and need it out of the way for the pipe work
- Building a stripped out race/rally car and it would give better weight distribution either in the centre or in the boot.
All of the above could perhaps be sorted by fitting a smaller battery but relocating is easy and cheaper
What you’ll need:
- Some thick cable
- Battery Box or battery tray/clamp
- Various connectors
- Circuit breaker
Starter motors draw a lot of current, even more so over a long length of cable. Go for something at least 25mm2, preferably 40mm2, this can be got from places such as www.vehiclewiringproducts.eu , www.cbsonline.co.uk
or even a welding suppliers (A good example can be bought from here) – this stuff has the added bonus of being more flexible so easier to route in tight spaces.
There’s a good chance you’ll need to pass the cable through the bulkhead, often there’s a blank grommet that can be used somewhere, or enough space made in an existing wiring grommet. If not then either drill and fit a large wiring grommet or a through bulkhead connector can be used (See some here) a bit more hassle but it keeps the +ve cable well away from the bodywork. Another plus is that it provides a useful +ve terminal – more on that later.
When routing the cable through the car any places where it runs across a metal edge it’s worthwhile either securing it so it can’t chafe or putting some rubber hose either over the metal or round the hose – both give extra protection. If possible run the cable along side the existing wiring loom, taped or cable tied together.
A box is the easy option and best if fitting the battery in the rear of a hatchback to protect you from the battery and its fumes (probably)
I made a simple tray and clamp from angle iron, designed to sit out of the way in the boot.
Whatever you use make sure it’s firmly secured to the floor and the battery is secure to that - you don’t want a loose battery.
Assuming the original battery clamp was crimped to the cable you’ll need a new one (and probably one for the –ve as well), there are many types available but fixing will either be by clamping the wire or bolting down a ring terminal. I like to use the gold audio ones as they have several different sized holes to allow multiple connections (useful for hard wiring fuel pumps or ICE).
To fit a ring terminal it will need crimping and/or soldering. Specialist crimping tools are available but satisfactory results can be obtained using a combination of vice, hammer and mole grips. Soldering will require a small blow torch as a standard electric soldering iron will not generate enough heat to get all the wire hot.
Take the battery end of the new cable and either attach a ring terminal or strip back enough insulation so it will fit in the clamp, but don’t connect it to the battery until you’ve finished. If you can’t re-use the old –ve cable then you’ll have to make up a new one it should be as short as possible and fixed to a good solid bit of bodywork/chassis. Clean it back to bare metal, drill a hole and bolt the ring terminal to it or you could use one of these…
which work in much the same way, attach to cleaned bodywork and clamp wire in.
Then you need to figure out the best way to connect the other end of the new +ve cable to the old battery cable.
These cable connectors are useful, just bare some wire on each cable and join together – crimp and solder.
Another option is putting another ring terminal on the new cable and connecting that straight to the starter motor, leaving the existing battery cable in place.
Third, and IMO, not so good option would be to fit a ring terminal to the old and new cable and bolt them together – a perfectly good connection but would need a lot of tape wrapping round to make it safe, I would certainly make sure it was secured well away from anywhere it could rub against and short out.
Another thing to think about is that there are usually several other wires connected to the battery +ve terminal that will also need to be reconnected to the +ve cable, which is where one of these distribution blocks comes in useful….
available from http://www.caraudiodirect.co.uk/celsus-pb1448.html?cadid=hqti1msudq6p7avqkbaj6k53o1 or ebay
If you’ve put the new cable to the starter motor then connect the old battery cable to the distribution block along with the other wires.
As mentioned earlier, a through bulkhead connector provides a +ve terminal in the engine bay - this can be used for connecting these wires to.
A circuit breaker (or large fuse) would be a wise addition, especially if the cable has been routed across/round metal edges. At least then if the cable does wear through and short out the circuit breaker will cut the power. Look at fitting something around the 140A mark, such as these….
From http://www.caraudiodirect.co.uk/vibe-cb140-circuit-breaker.html or, as always, ebay
Cut the +ve cable near the battery , fit a ring terminal (as shown below) to each end, attach to the circuit breaker and mount that firmly.
And that's about it. Just make sure before connecting the +ve cable to the battery that all the other connections are tight and insulated.
Good luck and please feel free to contact me (ChrisT) in the forum if you get stuck!
