Does anyone have a NEC laptop here?

I am a unfortunate user of a NEC Versa E680. After around 6 month's usage, I find that the battery life has diminished alot. Currently WinXP reports 1% of battery life equals 1 min. I have set the power settings to Laptop but its the same. WTF.

My specs:
Intel Pentium M 1.5 ghz (Centrino)
256 MB DDR RAM
35 GB HDD


I'd like to know if other NEC users have problems with battery life.