Performance measurement of power banks

Power supply efficiency: When voltage conversion and charging the power supply, the power will be lost, the less the loss, the better the performance.
Security:
Overcharge protection: Prevents the battery from overcharging.
Overvoltage protection: prevents the battery charging voltage from being too high.
Over-discharge protection: prevents excessive battery discharge.
Overload protection: prevents the output from continuing to discharge under the condition of high current.
Short-circuit protection: Prevents short-circuit detection at the output and stops the power supply.
Overtemperature protection: prevents excessive temperature.
Voltage and current stability.
The quality of the cell.