Hi guys,
me and my sister both bought the desire hd about a month ago.
I plugged it in for about 8-9 hours while off the first time and so did my sister.
The first week or so,the battery on mine lasted ten hours max.This is partly because I replaced my laptop with it!Mail checking,facebook,twitter,casual surfing,msn,skype,apps downloading and installing,customizing etc etc.Screen was on for approximately 4 hours everyday.
During the second week,the battery lasted for about 16-17 hours of heavy use.Wifi on when at home(about 8 hours),screen on for about 3-4 hours,out of which 2 hours or so where dedicated to gaming so the gpu worked a lot.I had my cousins over for 3 days so the games where a good way to distract them when in the car.
Calls for about 1.5 hours per day and about 30-40 texts coming and going.
3g always off as I don't use it.(Plenty of wifi hotspots at coffee shops so when I need to check something I stand stand outside a starbucks or something).Gps mostly off as I do not use it much.Radio on for 1 hour.Accelerator on and off at will because I text or e-mail when in bed.Screen is at 25% and saver at 30% of battery.
All in all,my battery has lasted up to a good 23 hours with medium use and around 16 hours with super heavy use.
My sister's phone lasts for 26 hours with heavy use though!I have no idea how this is achieved.Wifi on,3g on,calls,texts,games,mail etc etc and the battery works like a beast!!Not a clue about it.
Both phones have been ota updated and there is a difference in battery performance since then.
However,I cannot complain about battery much since the phone,is simply,amazing.The browsing experience is excellent partly due to the massive screen and partly because hardware/software power.Games look fantastic,music playback is decent(although I'd like the speaker to be a bit louder),and the looks are the best.The only real disadvantage is the speaker but it is totally something i can live with.I now use about 3-5% per hour on medium use and 7-8% on heavy use.On idle it is about 0,7% per hour.
A better battery would be welcome.
Cheers