My frontier is about 3 years old. It gradually started to lose battery capacity until I couldn't wear it even a few hours without it draining completely. Then I started having the issue where it wouldn't take a charge, at all. It won't even light up. I've tried multiple sources and different Samsung chargers (my wife has an s gear 3 classic). Nothing. Like it's not sitting on the charger at all. After a friend suggested it, I had the battery changed. It worked for 3 days just fine. Now the watch is back to not charging, or being recognized by a charger at all.