The Amazfit T-Rex 3 is rated for up to 27 days of battery life under typical use, and up to 13 days in heavy usage scenarios. For GPS, Amazfit lists 42 hours in Accurate Mode, 114 hours in Long Battery Life mode, and 180 hours in Max Battery Life mode.

Quick scoop

If you want the headline number, it’s 27 days on a normal charge cycle.

What users report

Real-world reports are usually lower than the marketing figure, with many owners describing roughly 10–14 days depending on settings like always-on display, heart-rate frequency, and GPS use.

Practical takeaway

  • Light to typical use: around 27 days rated.
  • Heavy use: around 13 days rated.
  • GPS workouts: 42 to 180 hours depending on mode.
  • Forum/user experience: often closer to 10–14 days.

If you want, I can also give you a quick “best battery settings” list for the T-Rex 3.