I got a new battery to fit to my donor car (so i dont have to keep jump starting it) until i get it running smoothly. The problem iv got is the new battery is too wide (about 2 inches) and will only fit at an angle. The positive wire reaches fine but the negative is about and inch too short. This might sound a bit thick but is the negative just an earth and if it is can i move it anywhere where it will reach?

For an earthed-body car, the black wire goes to the chassis so in theory yes. However, it all depends what is happening with a earth wire going to the starter motor etc. It's best to have a seperate cable going to that from the battery. If there isn't in your setup it may be that where the earth wire (from the battery) attaches to the chassis is right next to the attachment of the earth cable to the starter motor. Not ideal but better than the same situation with a big bit of chassis in between....

But to be fair preparation of the earthing point is more important than the actual location in most cases (ie take off any powercoating, abrade and clean it well, attached the earth cable then coat it to prevent corrosion)...

As said above.

Couldn't put it any better

read my responses in here

The neat and tidy solution is to fix the battery in the most appropriate place, then see if the leads reach the terminals without stretching or rubbing across edges. If, as in your case, a lead won't reach then either make or buy a new lead to do the job.

Halfords sell various lengths, or you could try Premier Wiring who will either have one in stock, or will make one up to match your requirements at no extra cost (he's a nice helpfull bloke).

Getting a new lead is not expensive, and far less pain than moving the chassis earth point (unless you have somewhere convenient already available that could be used).

Entirely IMHO, of course!

HTH,
David

Extend the wire to reach the earth terminal. It's only the donor just bolt another cable to it instead of the original and drill a hole for the other end somewhere convenient then use the cable on your car when it's done.