The charger to charge the phone can carry a 12V fan.
In fact, no matter which charger you use, you will basically lose battery life, but the length of time.
At the same time, such as small fans, Bluetooth headsets, all belong to small current charging, many chargers have the function of adapting to small current charging, but not necessarily all chargers have this adaptation function.
If you are worried that the fast charger will charge the small fan, you can choose to charge with a charging bank, many charging banks have support for small current charging, such as millet 3 mobile power supply, purple rice power supply and so on.
This is not possible, because the voltage between the two is not the same, and the voltage is not the same, causing the current to be different.
The output current of the charger of the mobile phone is generally 5 volts, the voltage difference required by the 12-volt fan is relatively large, and because the output voltage of the mobile phone charger is relatively low, the output current output power of the corresponding is also relatively low, which can not meet the needs of the 12-volt fan to start, so it cannot be used.