Yes you can bypass the battery with a bench power supply. But you won't be checking the functionality of the phone if you do not purchase a battery. it's supposed to work with the battery . Purchase the battery check out the phone, if you don't like the phone send battery back for a refund. The charging USB port will not power it. It's 5 volts in the first place. Your phone is responsible for charging the battery.
Low end phone Android Oreo Go operating system for Europe. Exactly the type of phones I like to experiment with. What I do is I create dummy battery so the phone will sense it has a battery in it. The phone checks if the battery is in good health, one needs the thermistor resistance value of the battery itself,that resistance is applied to the two pins on the battery contacts and two pins are for positive and negative power supply terminals on the phone. When in transmit the phone can draw more than 2 amps peak and if you're running apps that's even more current it must draw . A 5 amp power supply at 4 volts is what I normally use for my phone that never leaves the house. Works for me. You make one mistake and you destroy the phone you want to take that risk?
