iPhone 5 only charging after reboot and only a few percent
I run an iPhone repair shop. A customer of mine just replaced the screen on her iPhone 5 herself, but after the replacement the battery is not working as it should. At first the phone would not start at all, it said it had low battery and charger had to be plugged in. When the charger was plugged in, the phone acted as if it was charging, but nothing happened. After connecting to a computer USB instead of wall socket the phone turned on, and the battery was on 3%. After 30min, it said 5% and did not change. After rebooting the phone it quickly raised to 6, then 7, then 8%. It then stopped again. I tried rebooting, and same thing happened. (9%, 10%, and then stopped at 11%). I did this until it got up to 20%.
I then unplugged the charger, and it dropped about one percent every 30 seconds. After reaching 13 percent, it stopped dropping. I restarted the phone again without having the charger connected, and when it turned back on it displayed 70%. It quickly decreased to 65%, then shut off. I connected the charger again, and after charging for a few minutes it turned on again. This time showing 5%. It charged to 7%, and now it only charges two percent after each restart.
This is happening with her own charger and also with my brand new charger I got with my 5s, so the problem is with the phone. I tried replacing the battery, but the problem is still there... Any ideas?
Sorry if tl;dr... :)
Is this a good question?