New Garmin Fenix 6 pro battery drained 33% in 12 hours, no GPS nothing other than this watch face (photo) and phone connection that showed ~50/60 notifications during the day. I have
Amazon.com: Garmin Rechargeable NiMH Battery for GPSMAP 64s/Oregon 600 Series GPS : Electronics
NiMH Rechargeable Battery Pack for Garmin Astro 430