1. Inside the wall plug is AC power. There is direct current in the battery and power bank. Alternating current cannot be stored, direct current can be stored.
2. There is no positive and negative poles for alternating current, and the positive and negative poles of direct current cannot be interchanged.
3. The light bulbs and industrial machines in the home run on alternating current. The input current of the mobile phone charger is AC, and the output current is DC through the transformer rectifier, and then charged into the mobile phone, so the electricity used by the mobile phone is DC.
