Battery drain

Hi,

I recently bought Vivoactive 4 and since new I have problem with battery drain. When I got it I charged it to 100%. When I uplugged it, battery went from 100% to 80% in less than one hour. From 80% to 40% lasted full day. And then again from 40% to 0% in less than one hour. I tried three full charges,factory reset and battery drain is not getting any better...did anyone else had this problem?

Thanks