When the short circuit happens during the charging or discharging progress the power bank would automatically cut the circuit for protection Protect the internal component from the harm caused by static electricity prolong the life time of the power bank The smart power bank and recognize the devices. When the device is plugged in it will charge automatically, and when the device is plugged out it will power off into power saving mode When the input voltage is over certain level or if the output voltage has crossed the certain level the circuit will be cut out in order to protect the device and the power bank In case the input current is over flowed or the output current has reached to a high status the power bank would stop working in order to protect the charging device and the power bank itself.