When the available battery time is shortened considerably, a probable cause of this is that the battery has reached the end of its life.
The battery life will vary according to how it is stored and through general operating conditions.
This replacement battery will extend the life of your pda,

Suitable for:

•  DOPOD  C720, C720W,
• HTC  Cavalier, Excalibur, Excalibur 100, S620, S621,
• O2  XDA Cosmo, Orange, SPV E600,
• T-Mobile  Dash, MDA Mail,
• 35H00080-00M, 35H00080-02M, EXCA160,
• 4894128001232,
  
• 1050mAh,