HTC Cingular Wizard / 8125 / 8100 / K-jam / P4300 PDA Smartphone Extra Capacity 2200 Mah Extended Battery
This battery was cheaper than buying it somewhere else within the continent and works well with the phone.  The only draw-back is that it is bigger than the original battery.  It came with a new back for the phone but it does make the phone bulkier.