What ho one and all,

Recharging seems to be easy but I don't understand. I have a Galaxy J5 and I can plug it into the computer screen USB to not only access the photos, but mainly to recharge the battery.

Before buying a SIM package with phone for my wife (Moto E7i), I won an ebay auction for a Moto E. If I plug either of these into the same computer USB port, it does not charge but drains the battery.

Why does one phone charge but the other do not? And is there away to charge from the screen (or computer) front ports?

Thanks and toodle pip