Two places in Sheffield spring to mind, Maplins and Bardwells. You will have to know the dimensions (LxWxH, in mm) of the battery so it will fit. Also, the Amp/Hour rating, typically 12 volt @ 1.6 or 2 ah. there is also a tubular battery inside the bell box, these can vary slightly in length and voltage.
Update: possibly South Yorkshire Batteries on Shoreham St.
Last edited by carosio; 27-03-2010 at 08:28.