Hi mate, sorry your no further forward with your fault. Your battery should be in the boot under the spare wheel (for future reference) but I agree with Gareth, get it checked first as they're not cheap to replace and a good possibility it's not the battery that's causing the fault.
I had a few lights come up on the dash recently and it turned out to be something completely different to what I would have thought. These modern day cars with all the electronics can be very difficult to fault find unless you know exactly what you're doing. The vcds lead/software can be very useful if you can get hold of one.
Good luck and please keep us all updated on your progress, we all like to help each other if possible.
Cheers