I have been having trouble with a broken USB port for use with charging the phone and since Christmas and New Year is around there was no way to get a warranty replacement in time.
I had to improvise and in the end I came up with a really quick and temporary solution, making use of the GPIO pins on the phone.
Someone released some information about them on GitHub and I did some probing myself.
The Pins are somewhat aligned like this:
Pin 2 is 5V DC input, Pin 3 is Ground.
What you want to do is to take a USB charging cable and cut off the end with the micro USB port, then strip off the plastic around it and find the 5V and GND wire. (Search on Google for the USB pinout to find out which wire color is what)
Get some tape, tesa or duct tape and tape over all the pins but 2 and 3. Place the 5V wire of the charging cable on Pin 2 and secure it with tape, then do the same with the Ground cable.
If the cable is relatively thin you should be able to slide over the back cover.
Now just plug it into a normal phone charger and it should charge perfectly!
I’d write a more detailed instruction with pictures, but I’m authoring this post on my phone right now. This solution should be lots better than using an universal phone battery charger, since you can use the phone while charging. It also gives me the idea of building myself a wireless charging module in the future.