As you all know Sony has used a new horizontal all white battery icon in Xperia Z2 KitKat firmware which has got mixed response from the users; now can be installed on Xperia SP. XDA Dev Levered has modded the SystemUI.apk for Xperia SP so that Xperia Z2 battery icon can be installed on Xperia SP. It is a mod from Xperia Z2 original KitKat SystemUI and only to be installed on Xperia SP.
To install it on your Xperia SP, it must be rooted, just download the below mentioned file and push it in system/media/app folder and replace it with the available file. Set correct permissions rw-r-r and do reboot. Kindly make a backup of original file before replacing it with the modded one.
Download Xperia Z2 battery icon SystemUI Mod
Note: Only for Xperia SP rooted users, do no try it on other devices.!
Check the preview of Xperia Z2 battery icon SystemUI Mod on Xperia SP below.
Bugs: Power saver and charging icon is still old one.
Let us know if that works for you on your Xperia SP. Drop your comments below in case of any doubts.