Let’s first of all see what all we’ll need to proceed further.
1. A Wireless Charging Set. Palm Touchstone or Qi charge will both do just fine.
2. A Standard Charging Coil, which will go inside your Mi4.
3. A Soldering Iron.
4. A Rosin-Cored Solder Wire.
5. A Multimeter.
5. Heat Shield Stickers
6. Positioning Irons.
7 A Screwdriver.
Firstly, open the rear cover of the phone. There is a coating of thermal grease on the inside of the back cover to keep the battery from overheating. It’s an adhesive compound, so while taking the cover off, make sure you don’t ruin anything else apart from the coat of paint.
We need to use enameled wire here.
The normal charging voltage is around 5.6 volts as you can see from the image above. It will take longer than usual for the phone to charge fully.
The following image is a low resolution photo shot by mobile camera.
The current is steady between 0.8 A and 1 A, using a standard 5V / 1A charger