We took a look at the new update: This $226 Garmin Fenix alternative just got even better

Zepp Health is rolling out a new software update for the Amazfit T-Rex 3 (currently listed at around $226 on Amazon). The 16.21 MB update upgrades the firmware to version 4.10.5.1. As usual, it is unclear whether the rollout has reached all users yet, though we were already able to install it. The update introduces several new features, most notably HybridCharge—an enhanced version of the BioCharge system—which is now available directly on the watch instead of being limited to the companion app. Users can also simulate Hyrox workouts. Additional changes include improved distance calibration for rowing machines.

HybridCharge is the standout addition. Like BioCharge, it aims to estimate your body’s energy reserves, although these cannot be measured directly. Instead, the score is based on a proprietary algorithm, with no details disclosed. It factors in various inputs—for example, values typically rise after restful sleep and drop following intense workouts. A new alert system can now notify you during exercise if your intensity threatens to deplete your remaining HybridCharge reserves. You can also log lifestyle metrics—such as perceived sleep quality—directly on the watch, eliminating the need to use the smartphone app.