Batteries on old cell phones can experience a decrease in battery power for several reasons, such as old battery age, excessive use, or damage to the battery.
In addition, another factor that can cause an old cell phone battery to not charge is a problem with the charger or USB port of the cell phone.

If you experience such problems, we recommend that you try using a different charger and cable to ensure that the problem is not caused by the charger or cable.
If the problem persists, you may need to replace your phone battery or contact support for further assistance.