When I got the phone, I had to charge it daily and I must say, I was really disappointed. Now I have owned the phone for 2 weeks. Last time I used it 3 days without recharging. This time I charged it about 40h ago and the battery status is still 90% full. So I suspect, it might last 4 days this time.
What has changed?
1) In the beginning I was discovering its features, so it was under heavy use. Now I mostly use it for phone calls (3-5 calls a day) and SMS's (3-5 SMS's a day), occasionally make a photo, check battery status etc.
2) In the beginning wifi, bluetooth, 3g, background data and gps were on, display was max brightness. A week ago I disabled wifi, gps, 3g and background data. Battery use is now: 33% cell standby, 33% bluetooth, 33% phone idle.
3) In the beginning, I connected the USB cable to exchange data. Sometimes I did not fully charge the phone. Now I only connect the cable when the battery is absolutely empty and disconnect it when battery is full.
4) Now I use back-key instead of home-key