I just bought a new one last week because my display was dimming when I used it for the code. It would be mildly dark when I pushed it but would fade quickly.
It's only $11. I figured I could just pony that up and have a fresh one than crack it open to replace the battery.
Current: FFXIV | EVE Online (again)
Former: FFXI | The Matrix Online (FOREVER!!!) | STO | SW:TOR | EQ2 | WoW | Florensia | RF Online
FFXI :: Valefor :: Dareknight, Darexius
FFXIV :: Valefor :: Dare Knight
EVE Online :: Dare Knight, Hazel Knight, Rex Knight