As mentioned in my other post:
http://www.mympxplayer.org/2-gb-glac...em-vt3979.html
I have completed back to back tests of the Uxcell supplied Glacier battery (BL-4C compatable) and a genuine Nokia BL-4C.
Uxcell - 3.5 hrs on constant video play (vol 17 through headphones)
Nokia - 6.5 hrs on constant video play (vol 17 through headphones)
Will try with MP3 playback but am guessing that the Nokia should provide almost 20 hrs. This is based on Hotboxx's findings that Uxcell battery lasts 10.5 hrs on MP3 with display off.
The genuine Nokia is a "factory reconditioned" one.