Have been doing some tests recently. Sat my Pre2 on the Touchstone and waited till it boinged to tell me charging was complete. I then checked Dr Battery and it said it was at 94% with 1005mAh.
So I wondered and turned the volume down and left it on the Touchstone. It kept silently telling it was done but I managed to get the charge up to 1064mAh and 99%. Dr Battery says my phone only has a max left of 1093mAh after 9 months use.
I then switched the phone into standard 2G GSM mode and have left it that way since.
23 hours later I'm sitting at 90% and 955mAh. Thats no calls, just sat in standby with the odd check to see the battery state. I use Battery Saver from midnight till 7am too.
Curious to see what's the max I can push from my Pre2 in a non data mode and then in a normal data mode.