I used my watch rarely over 3 years. Now battery is dead. Even not one day in standby watch mode. :-| Battery isn't changeable. :-|

Zero Sustainability! Over 250€ are gone completely.

I just upgraded to the Instinct 2. I only took my Instinct off when showering or charging. Charged it when 1 or 2 bars on the guage. Used it 5 times a week when hiking. After 3.5 years there was no noticeable decrease in battery life from when it was new. That being said, I'm comfortable giving it to my son for his use.

On my instinct solar it was less than 2 years and Garmin is replacing it. The watch would crash when anything happened that would use a larger than normal amount of power. For example an alarm going off, a phone notification coming in in, or when you started an activity.The battery would drop from 100% to 80% within a few minutes of disconnecting it from the charger .My old forerunner 35 is 5 years old and still going strong.

I have been using it actively for about 3 years and I have no battery issues noticable. It was always charged full when the battery bars empty and I didnt care about %80-%20 rule. I think it is somewhat durable compared to that of mobile phones

14 months is all it took for the battery on my instinct solar to fail. It no longer holds its charge and it will only last a few days once charged before it shuts off. Of course it is out of warrenty now too. 

My old Instinct purchased more than 4 years ago, not really handled with any precaution, and heavily battered with ~100 activities/month of all kinds, still serves fine (now, to my friend).

@trux you're lucky. The battery on my 6 year old Forerunner 35 is still pretty good, but my first Instinct Solar was replaced under warranty after about a month because of a faulty battery; the replacement lasted less than 2 years before Garmin replaced it as well because the battery was dying and it was crashing all the time

I have the Garmin Instinct Solar which was first powered on in June 2021. This makes it almost 2.5 years old. It has ~73% of its original battery capacity when only exposed to a few hours of sunlight per week (pretty low solar exposure at the time of testing). I got 19.6 days of battery max, which depends on your settings and use. The watch would always say 28 days at full charge but drain more than 1 day per day basically. During time of testing I did not do any activity tracking like GPS. Constant heart rate monitoring and bluetooth connection to phone. No pulse oximeter overnight. Occasional backlight use to see the time. Backlight is on for notifications. I bought it used so I do not know how it was used or charged for its first 2 years of life.