Battery Life on Desire HD Why does the battery for android phones perform much better after 2 or 3 weeks of usage? Is there any logical reason?
I'll agree with Al Everett and say that the amount of playing with the new toy is certainly a factor early on.

I also did not notice any intrinsic changes in the systems battery management over time.  I did however notice a massive increase in battery life by turning off auto-sync, and even mobile on occasion.  With those two on, I'd see a significant drop in battery when I slept overnight, but it doesn't budge with those two off.

I use two power control widgets, the HTC data dashboard and the Android power control widget. Between the two, it's a piece of cake to tweak power settings to make sure I get the most out of the battery.