Got back to the office after a week away to discover the PDA (Qtek 2020) in 3 pieces! It was left on charge as the OS is Pocket PC 2003 and loses all stored info if battery uses up all charge. The battery had swollen and burst the case

. Has this happened to anyone? The battery is rechargeable "Li-ion polymer" - have I a fire hazard or is this the expected end of life after 3 yrs?