Speaking of Xiaomi charging head can charge Apple xs to the battery harm; It is better to say that millet charging head to Apple xs charging harm. Why do you say that?
First of all, whether it is Xiaomi or Apple, even if you use your own home charger to charge your own home mobile phone, it will cause harm, because lithium batteries have a life, and the battery life will be reduced when the number of cycles reaches a certain number of Apple phones. The same official also has reached 500 cycles can also maintain 80% of the battery capacity (less than 80 warranty period can contact after-sales free replacement). Xiaomi is also a lithium battery, the number of charging cycles will reduce the battery capacity.
So can the Xiaomi charging head charge the Apple xs? The answer is yes, the Apple 8 series and above support the PD fast charging protocol, and the Xiaomi PD charging head is also compatible with a variety of protocols, and it is also said in its official publicity that it can charge Samsung, Apple and other products.
However, Apple's official advice, including my suggestion, is to buy products with MFi certification (MFi certification is Apple's official certification of its authorized accessories).
I am currently using is through this certification of charging equipment, have to say it is really sweet, the only disadvantage is to go out with the line is very inconvenient; And a PD power bank.
It is recommended that users try to buy MFi certified chargers when purchasing.