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
Samsung Gear S3 Frontier Review: A Hefty Smartwatch Full of Features
Watch only mode on the Gear S3 (and Gear Sport) can extend battery life by 40 days! - SamMobile
Samsung release Samsung Gear S3 update to addresses battery life issue - IoT Gadgets
Performance | Samsung Gear S3 - The Official Samsung Galaxy Site