PYK, I am glad to answer the theory, DC charging is fast, but there is still some damage to the mobile phone battery, and AC charging is slower, but it can be determined according to the situation of your mobile phone at that time is fast charging or to keep the power use, charging too fast and power consumption, can cause casualties, and in the state of the mobile phone off, the mobile phone can be quickly charged, it can be said, Ac is a smart current, it is recommended that you use AC more, however, it is not recommended that you are below 10 grid, AC will try to keep at 10 grid, so 10 grid below will be fast charging, but also may cause harm. Thank you very much.