A 5-volt power supply cannot directly charge a lithium battery. Lithium battery overcharge is easy to damage, so the charging overcharge requirements are more strict, the charging termination voltage should be controlled at 4.2V±0.05V, the charging current is generally recommended to use half the battery capacity of the current is 0.5C, fast charge is recommended 1C to 2C. If you use 5V voltage to directly charge the lithium battery, there is no way to control the charging current and termination voltage, which may cause the battery to overheat and explode or overcharge damage. It is recommended to use a dedicated charger for charging.