Battery life in dual-boot HTC HD2 I own a dual-booting HTC-HD2 with MIUI on SD card.

I already knew, from tutorials, that in order to maximize battery life I should first-boot Android only with 100% of charge.

This is currently unclear to me. First, I run Windows Mobile 90% of time, and I use Android occasionally only for some programs that are not available in WM.

It happened that I needed to boot Android when on the street, with less than 100% battery. However, I recently noticed that my battery is descharging really fast, for example today from 7:30am to 10am it ran from 100% to 68%, and I really wonder if it could have lasted till 8pm (when I get back home).

Is it because Android should always be booted with 100% of battery, or because I run 24/7 Skype and Windows Live Messenger in HSDPA from Windows Mobile?

Thanks
No, it is because at first boot (ie: inizialization), Android creates a Battery stat file to calibrate the battery.
After the first boot, you can start Android with any battery percentage.

If you think that after a long time, the battery percentage is not correctly reported, you can force Android to recreate the stats file with some root utilities available in the Market

Skype/MSN do draw a lot of battery, anyway, if you are using them from Windows Mobile, they are not running from Android.

You could try using greenpower or juicedefender to see if the data connection is the problem