Wow,
Haven’t kept track other then 3 cells since I purchased it (on its third now). I was an early user and purchased this in January, 2015, when it came out.
Now, the caveat, I hardly wear it but I keep it powered and check once a month. So the 3 batteries in almost 5 years (January 2020) is a very “limited use” power consumption and very anecdotal.
Love the watch though.
Geoff