since you asked, and i'm not claiming to be an expert....
car batteries generally used to have horrid clunky terminals totally different from and unsuitable for bike use. i think they do have better terminals now?
also, the old lead/acid car batteries did not have spigots for an overflow pipe, so if the bike fell over, acid went everywhere.
so a nice gel car battery with the right terminals would be fine, if you can fit one in
Ta for the help guys and sorry for the hijack.
Jay,
that looks grand- though i think €50/60 is more likely here.
Cookie,
clunky- my whole Bike is one large clunk!
Yep - that's what i have now. No complaints - though (as i remembered recently to my cost ) they get furred up and bad contact/crap charge unless you are fussy with them.
Ta for the replies.