Q: replacement ibook g4 battery doesn't fit: compatibility issue or defect?

The battery in my 14"  iBook g4 stopped holding a charge, so I ordered a replacement through Ebay where it was listed as an Apple battery for a 14" iBook.  Once it arrived I saw that it was labeled as Model No. A1062, whereas my old battery was an A1080.  They looked identical externally so far as I could see, but I can't make the  A1062 fit into its slot--one corner stays elevated.  Have I just ordered the wrong thing--are A1062 and A1080 supposed to be incompatible? Or is there something wrong with the battery?

Any advice greatly appreciated.