19.With such a high output power of KA13, will the battery life of the mobile phone be greatly affected?

Generally, the higher the the rated output power of the USB dongle, the higher supplied power is requireed from the mobile phone which will lead to a decrease in the battery life of the mobile phone.

However, we also need to check the actual situation when using products with high output output. For example, for high impedance headphones, what is needed is a high voltage without high current. And for particularly low impedance headphones, the need is for high current but not high voltage.

And in general, audio devices with high output power usually have higher output voltage and higher output current in order to drive high/low impedance headphones better.