Here's a list I've compiled over the past 6-8 months. Hope something on it will help you. It is not specifically for the D2, but most should apply:
Battery Life
Here's my tips:
1. (Doesn’t apply to all phones) Go to settings/wireless & networks/mobile networks/Enable always-on data. Uncheck always on data. Your phone will still receive email, text, & phone calls as before as well as internet usage but your battery will last a lot longer.
2. Emails: I don't know what email app you use, but try this. It saves battery power and in some cases emails arrive quicker. This scheme will have you using only the Gmail app on the phone for all email accounts whether they are pop3 accounts or Gmail. Go to the Google Gmail inbox on your computer and log into the Gmail account. On the top right of the screen is an option called Settings. In there is an option to have the Gmail program poll your regular, non-Gmail accounts. Provide the email address and the password. The Google Gmail program will then poll your other accounts on a frequency from 1-5 minutes and push the email immediately to your phone. The polling frequency is determined by each account's activity - more emails = faster polling. It will always be no less frequent than every five minutes. This saves battery power because on the android OS pop3 accounts are polled at a frequency of 1-30 minutes and that really eats battery. Because the phone goes and checks those accounts for mail whether there is mail there or not.
3. If you are using Live Wall Papers, stop!
4. Use wifi any time it is available. It uses a lot less power than 3G and it is much faster.
5. If there are widgets that automatically update (facebook, weather, etc.) change their update frequency in their settings menu. Set them to 30mins or 1 hour.
6. Oh, almost forgot, get the extended battery from Verizon.
7. Turn off the GPS unless you are actually using it. There are some background apps that can burn a lot of power via a live gps.
8. The Power Control Widget is a good tool for easily turning on and off some of these features (gps, wifi, screen brightness, etc.).
9. From the home screen do the following: menu/settings/About Phone/Battery Use. This graph will show the 10 biggest power users on the phone. It should always be Screen as the top user and the android os, android system, phone standby and phone idle should be the other top users. If there is an app listed you should determine if it’s an app you actually use a lot or do you have a rogue app that needs to be uninstalled.
10. Get Screebl. It will turn your phone off anytime you are not actively using it.
11. If you have either a task killer or an anti-virus app installed, you should uninstall.
12. Go to data>system>and delete batterystats.bin after you've charged your phone to 100%. Helps with accuracy of battery meter.
13. D2G - go in to settings, wireless and networks, mobile network and change the network type from global to CDMA only. The d2g is locked out from using the local GSM networks in the US. You don't need global radio turned on in the US just overseas.
