New battery
Just fitted a new battery, last one an Exide battery lasted over 6 years but ran dry so was stuffed. New battery is a Bosch AsiaSilver which is recommended for JDM cars plus it was the largest one that fitted, width wise there is only about 5mm clearance left. I got mine from Costco so it was a lot cheaper than retail but it should still be only around £50.
Piccy here: http://www.redfto.co.uk/Images06/battery.jpg