Before a time I criticized battery life of my HD2 flashed by energy rom . Last week I installed new version and it seems that HD2 can simply alive almost four days per one charge! I'm usually read internet at least 30 minutes per day, write a few messages, sync to google exchange, couple of calls. How to improve HD2 battery life? install energy rom :-) definitely switch CHT (Cookie home tab) Editor's lock screen off. Despite it makes your device really unstable , it drains battery a lot - use WM's default because the android version can be simply unlocked in a pocket - significant battery life improve use GPRS instead of 3G - significant battery life improve lower backlight to 20% - it's enough for almost all cases switch vibration when any virtual key is pressed off install all programs into main memory switch weather animation widget off