apple watch series 6 fast charge

Hello Patipan-PNWTN,

It sounds like you have questions around fast charing your Apple Watch.

Apple Watch can be charged using the Magnetic Charging Cable in conjunction with a USB port, an Apple 5W USB Power Adapter or an Apple iPad USB Power Adapter:

Check your battery and charge your Apple Watch - Apple Support

Apple Watch uses fast charging for the first 80% of battery capacity:

Batteries - Why Lithium-ion? - Apple

Expected charging times are around 1.5 hours to 80% and 2 hours from 0-100%:

Apple Watch - Battery - Apple

Note that Apple advises that you can charge Apple Watch whenever you want. There is no need to let the battery discharge to any particular level first, nor any benefit to be gained from doing so.

Apple's tips for maximising battery life and battery lifespan on Apple Watch are detailed here:

Batteries - Maximizing Performance - Apple

This should help to clear that up for you.

Take care!