Most tech heads I know are big fans of droid powered devices, especially cell phones. I have an evo 4g myself, and like many droid cell phones it tends to eat up battery like I do carrot cake. This is a quick guide to save battery power, and will work on most droid phones. I searched the internet and found a plethora of suggestions to save battery power, many worked some were just pointless. Here is a compilation of what I feel works the best.

Go to Settings → Sound & display → Brightness. Slide the brightness switch to the left to lower it or check the “Automatic brightness” box to let the EVO use its sensors to adjust the screen according to the ambient light. You can also find dedicated screen brightness widgets in Android Market.

The easiest way to manage these wireless radios is to use the Settings widget preinstalled on your EVO. Tap the + button on your home screen → Widget → Settings. Once your chosen widgets are on any of your home screens, a simple tap turns each one on/off. There are other widgets that do this in Android Market, but these are already preinstalled and they're a nice-looking set.

Go to Settings → Wireless & networks → Wi-Fi settings. Uncheck the Network notification box so the EVO isn't constantly scanning and looking for open networks to tell you about. For 4G, go to Settings → Wireless & networks → 4G settings.

This is one of the biggest battery savers. Go to Settings → Wireless & networks → Mobile networks. Tap “Enable always-on mobile data” to uncheck the box. I haven't found a negative consequence of disabling this feature, as Gmail and other apps/functions still work perfectly.

If you're not using Google services, go to Settings → Accounts & sync and uncheck the Background data box so that applications cannot sync, send, and receive data whenever they want to.

The EVO's screen can be set to automatically turn off when you don't interact with it for a predetermined amount of time: 15 seconds, 30 seconds, 1 minute, 2 minutes, 10 minutes, or never. Depending on what you're doing, a too-short interval can become annoying (especially if you didn't disable your lock screen), so choose wisely.

Its not a big project to sync manually and will save power to just turn auto-sync off. Go to Settings → Accounts & sync → Auto-sync.

Go to Settings → Location → Use wireless networks. Note that this (or one of the other options) needs to be enabled if you want to see and/or use your location in apps like Maps.

Live wallpapers were one of the new features in Android 2.1, so it feels like a step backward not to use them. They don't hit the battery very hard when used, but they do make a small dent. So if you're trying to improve battery life, even if only incrementally, use a static wallpaper instead.

This may sound counter-intuitive, but leaving WiFi on when the EVO isn't being used and the screen is off is actually better than letting it sleep. When WiFi sleeps, 3G/4G wakes up to sync, get email, and retrieve other data. 3G will eat up more battery than WiFi, so go to Settings → Wireless & networks → Wi-Fi Settings. Press the Menu button and tap Advanced, then Wi-Fi sleep policy. Choose “Never” from the pop-up menu.

Widgets that need access to the internet to update information (e.g., Facebook, Twitter, Engadget, Slacker Radio, Weather, Stocks, News, Mail) can suck up a lot of juice if not managed well, so choose them carefully and set their sync/update frequencies to a reasonable interval or disable them completely.

This may not be practical if you're someone who really needs/wants to know when something happens on your phone when you're not looking, but for everyone else, feel free to turn off those notifications. Go to Settings → Sound & display → Notification flash and uncheck all the boxes.