Battery daily power varies on Apple Watch
Last week the Apple Watch 5 battery power drained to red (low battery) within 6+ hours, repeated this daily for 4 days with otherwise my normal use on normal days. Then suddenly went back to normal, about 40% remaining after 13 average hours per day for next 2-3 days. Now has returned to rapid drain to red, 15% in 5 hours. Routine is to charge to 100% overnight. Any suggestions? Recently upgraded to latest iOS on the watch.
BTW, my 2nd generation watch I now resumed wearing remains about 75% at days end while I look at the Watch 5 "resting" on the charger from lunch hour on.
Apple Watch Series 5