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 – S Health, Fitness Tracking, Battery Life and Verdict Review | Trusted Reviews
More power for the Galaxy S3 with Mugen Power 4,600 mAh extended battery
How to Improve Battery Performance at SAMSUNG GALAXY S3 MINI I8190 (Battery Saving) & Make Battery Not Fast to Drain - Hard Reset & Factory Default Community