Just completed filming my pilot episode for xda-developers TV. I did a show on some basic functions to get better battery life out of your Android phone. I did quite a bit of research while working on this episode.
If you want to look into it further, please check out byrong's thread: on the xda forums. He did some really good work looking into how batteries charge and how the phone reports the current battery status.
Also please check out Battery Problem? by kthejoker20, also on xda forums. He details the method I've heard several places about resetting the battery gauge on your phone. I don't know the entire spectrum of devices this trick will work on. If you have some good feedback on this technique, please leave a comment.
I mentioned two widgets in the video, SwitchPro, and Power Control Plus. Both are available in the market. Use the QR codes below to find them.
This one is for SwitchPro:
This one is for Power Control Plus:
Here's another good thread, Tweaks for Superb Battery Life in EVO with most of the same information about battery life and somethings you can do to make the battery last a bit longer. egzthunder1 put that article together from a wide range of sources. That info should be valid for most phones.
In the upcoming episodes, I'll look at some ways you can automate your battery saving efforts with some apps. I'll look specifically at Tasker, which has a strong following and an amazing range of features beyond battery saving. I'll also look at an app by Chainfire called Super Power. Super Power has a range of features specifically oriented to save battery. They go from fairly standard to complex and even take advantage of different functions only available on rooted phones.
Here is the QR for Super Power.
If you have any particular theories about extending your own battery life, leave them in the comments.