Newbie here with the n900. Here is the two test that I've done with my phone with approximately the same type of usage over a day. I did both of these test twice and got the same outcome both times.

Test 1 - Fully charged the battery, from dead, in the phone and kept the wifi off and my cell service on 2g except when I needed it to be otherwise. The result was my battery would last around 4 to 5 hours.
Battery charge time was approximately 3 to 4 hours to full charge according to the phone.

Test 2 - Fully charged the batter, from dead, in an external charger then ran the same service as test 1. The result was my battery will last around 11 to 14 hours. The battery charge time was approximately 6 to 7 hours to full charge according to the external charger.

What does this tell me?