From what I've read, the X1 battery controller supports no other than 10% increments. If the hardware is not able to tell the software what the % is, nothing can help you.
"There is no good, nor bad - only perspective, and opinion."
- Sony Xperia X1 (WM6.5)
- HTC HD2 (CM Android 4.0)
- ASUS Padfone + Station & Keyboard (Stock Android 4.1)
- Sony Xperia Z1 (Modified Stock Android 4.2)