After a failed Toyota Battery and an Optima Yellow top seeming to drain after a few days I have bought a brand new battery from Halfords.
The Yellow Top was a car audio battery which had been out of my Civic Type R for about a year which probably didn't do it any favours, and my car has been lazy starting for ages with the Optima even after a charge.
The new battery was installed last night with a 510 crank on it so plenty of juice, so only time will tell if it also goes flat then I can definately say it's not the batteries.
There are no components that I can trace which would be flattening the battery so god knows what I will do if this goes flat.