Amazfit Watch faces

Got the GTS for a family member yesterday, I set them up, heart rate monitor every 5 minutes, always on display enabled 5am to 22pm. When It finished all the updates and setting up, it was sitting at 51% of battery. They were used twice for 1hour walk (= 2 hours of walking mode) + general use like walking around the house with them. 10.0.0.0.1 192.168.1.254 hotmail.com

Now the battery is dead, they went to 0% within the 24 hours since the box was opened and the watches set up. While losing 50% of charge in 24 hours in not uncommon for some watches (like apple watch) I bought these based on the reviews claiming excellent battery life.

Does anyone have similar experience/idea what might be the cause?

Factory reset
Firmware update
Recharge it on a 5V 1A "wall smartphone charger"
(Galaxy grand prime wall charger is 5v 1amp... it s an old product but it s a branded charger under 6€ - $7 and you can still buy it on various place)
At 100% battery... don't unplug it... let the GTS charge even if it say that it s already 100% for 1 or 2 hour.


Cause :

not calibrated battery

already dead battery from start ( send the gts on warranty )
-> you have no luck... you can just send it...