Can a power bank charge your phone
No, unless you're using a poor-quality portable power supply. Because those unbranded mobile power supplies, in order to improve profits, will cut corners on the product, such as the precision of the board, the poor line, the use of second-hand batteries and so on. These unstable factors can cause different degrees of damage to the phone.
Poor quality (unqualified) charging treasure will cause damage to the mobile phone (charge explosion), good quality charging treasure has protection function, full charge will automatically power off, so buy charging treasure to pay attention to quality is good.