All of the sudden my Fenix 6X S just started reporting 16 days of battery life at 100% rather than 9 days. Did they do a major battery optimization update recently? : r/GarminFenix
Garmin Fenix 6X Pro Solar comparison and test in the detailed review
Garmin Body Battery on a Fenix 6X - Does it WORK? - YouTube
For Garmin Fenix 6x Pro 6x Pro Solar Gps Watch Back Cover Case With Rechargeable Li-ion Battery Replacement Part - Tablet Lcds & Panels - AliExpress