Vinchenzop over at XDA has released a series of flashable battery indicator mods for rooted HTC EVO 4G LTE based off of Jotha’s work for the One X.
These mods allow you to see the percentage of battery left in various forms such as a bubble, an android filled with juice, a circular indicator, gas-tank indicator, etc.
The flashable zip also includes the 1X/3G mod to let you know when you’re not in 3G service, and also includes Mik’s Extended Quicksettings mod. All of the versions appear to have the MIUI-style battery line indicator up at the top as well.
You’ll need an unlocked EVO and a custom recovery to install any of these mods.. And since they change a lot of stuff that your ROM may or may not like, go ahead and make a nandroid backup before flashing any of the mods, just to be safe.