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
How To Replace Samsung Gear S3 Battery | 𝑺𝒎𝒂𝒓𝒕 𝑾𝒂𝒕𝒄𝒉 𝑹𝒆𝒑𝒂𝒊𝒓 | Get Fixed - YouTube