Currently the Seidio InnoCell is the only larger capacity battery out for the Evo 4G.
Mostly all of the reviews I have read stated that these battery are on-par if not worse then the Oem Batteries.
Best bet is just buy other Oem Htc Battery and call it a day! As everyone uses the phone in a dissimilar way battery life will be dissimilar for each situation. Try some of these battery recovery tips for the Htc Evo 4G:
- Try to sacrifice the brightness of the Screen ( huge savings)
Go to Settings -> Sound & display -> Brightness.
- Try To turn off "always on" mobile data.
Go to Settings -> Wireless & networks -> mobile networks.
- Try to Turn off auto-sync.
Go to Settings -> Accounts & sync -> Auto-sync.
- Try to save by turning off the background data. So that applications cannot sync, send, and receive data whenever they want to.
Go to Settings -> Accounts & sync and uncheck the Background data box
- Try to Turn off haptic feedback.
Go to Settings -> Language & keyboard -> Touch Input -> Text input -> Vibrate when typing.
- Try To Disable Network declaration (Wifi, 4G)
Go to Settings -> Wireless & networks -> Wi-Fi settings. Uncheck the Network notification.
For 4G, go to Settings -> Wireless & networks -> 4G settings.
- Try to Use a dark wallpaper. Some say that dark wallpapers are more energy sufficient than light wallpapers.
- Disable data roaming if you don't need it.
Go to Settings -> Wireless networks -> mobile networks.
- Change the Cdma roaming mode.Go to Settings -> Wireless networks -> mobile networks.
Tap on "Roaming" and elect "Sprint only" from the pop-up window that appears.
These Basics Tips in a way or other will help any Android Phones in the market (Android 2.0 and up)
How to increase the Htc Evo 4G's Battery Life