Battery question mark on a phone?
A couple of days ago, our technician solved a battery question mark problem on a Google Pixel 4XL.
That phone could not be powered on successfully nor could it be charged properly. It just showed a battery icon on the screen with a question mark in it, as the pictures below show.
What we did to solve it?
Back glass of the phone was removed carefully and the motherboard and battery were taken out. Our technician checked the battery connector and motherboard under microscope and could find nothing wrong.
The customer was informed that it might be battery or motherboard problem. It’s a good idea to try a new battery before we move to motherboard, and a quote was given.
A new battery was ordered and arrived in 3 days. On the same day, our technician replaced the battery in and issue solved!
Deep diving into this issue
Battery question mark on a phone is not a common problem.
A phone battery is more than a general battery. It has not only energy storage materials inside, but also has management data on a small circuit board attached to it. The management data including serial number, charging loops, capacity etc., which is very import for charging. Because a smartphone always try to read this information before it starts the charging process.
Understanding the above knowledge, it is easy to figure out the following possible causes:
1) battery socket is loose or bad connection between the battery and the motherboard
2) information on the battery is missing or damaged
3) open circuit on the motherboard between the battery and cpu