[Highland Park] Sanyo Battery?

Does anyone happen to have an old cell phone battery that they don't use anymore....for a Sanyo? I love my old phone and i don't want to change it but the battery will only hold a charge for about 20 minutes at MOST. I would hate to go buy a new one if someone around HP has an old one lying around that they don't need/use anymore. i can even buy it off of u if u want. THANKS!!! Taryn