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
430mAh] Battery for Samsung Gear S3 Frontier (SM-R760, R770, R765), Gear S3 Classic Replacement Battery EB-BR760ABE GH43-04699A with Professional Repair Tools Kits: Amazon.co.uk: Electronics & Photo
Source Factory Original Smart Watch Battery for Samsung Gear S3 Classic Frontier Tum Replacement Bateria on m.alibaba.com
Samsung Original Battery EB-BR760ABE For Samsung Gear S3 Frontier / Classic EB-BR760A SM-R760 SM-