Bettary life has reduced drastically

Since last week, my garmin instinct has been dropping bettary like its an old gen Apple watch. Before it used to last me 14 days. I was okay when I use it for biking and it would last for 10 days with full charge. But now for last 2 weeks, its not holding itself any good. Its been dropping from 4 days to now 2 days with full charge. I am not sure what is the issue as i only turn on for cardio workout and rest its just stays on my wrist just doing smart watch thing.. amy suggestions?