Forensic Battery Lab

How long does your GPS watch really last on your route?

Manufacturers test in a lab: room temperature, no cold, screen off, GPS at its laziest setting. Then they print that number on the box. Load your GPX route here and we calculate what’s left once the real world gets involved. Every figure comes from one published formula, nothing hand-waved.

The Gap Is Real

Garmin prints 82 hours on the Epix Pro Gen 2’s box — measured in single-band, the laziest GPS setting. Run your alpine route the way you actually would, in multi-band accuracy through cold and wind, and it blacks out at 13.7 hours. An 83.3% gap — part physics, part a number that was engineered into the spec sheet. Not every watch fails this way: on the same segment the Apple Watch Ultra 2 actually beats its own claim. That’s the point. We calculate the difference, watch by watch.

See a Live Audit

Garmin Epix Pro Gen 2 · forensic audit83.3% gap[ CRITICAL ]Suunto Race · forensic audit59.1% gap[ CRITICAL ]Apple Watch Ultra 2 · forensic audit-13.0% gap[ SAFE ]

Each link is a real audit from our database, showing one segment of a route. The gap gets worse in the cold, dark segments that come later.

Audit Your Own Route

Got a GPX file from AllTrails, Komoot, or your watch? Drop it in and run the numbers for your device on your exact route.

Drop GPX file here

AllTrails · Komoot · Generic