I own a caddy, for golf, ...
A flat battery won't work, because its well flat.... It uses a flat battery ...
Did you not get a mains charger for the battery when you bought the caddy or is the case that the battery won't hold a charge?... It is wearing out-where will I get a new battery?...
As already suggested did you call into Dunnes?... I would prefer not to buy a new caddy just to get a new battery!...