the nokia BME is inaccurate. After a while you might notice your battery suddenly go up.

Last weekend I had 15% battery remaining when I left home, 2 hours later I had 18% remaining. Whaaa? :P

If you install H-E-N and run it, it stops BME. Upon exiting H-E-N, it restarts BME. You can see the battery level change wildly every time.