Just replaced my Gear S3 battery (24$ + 10$ for tools). Excited to get 3+ days back. Links in comments, will report back with new battery life in a few days. : r/GearS3
The Samsung Galaxy Tab S3 (SM-T825) Tablet Review | Page 5 : Work Performance, Battery Life & Recharging Speed of 7 | Tech ARP
Samsung Gear S3 Classic and Frontier: Extend Your Battery Life with These Battery Saving Tips - YouTube