From their website: "Consumer Reports tests hundreds of laptops each year, using identical procedures in highly controlled conditions. For the battery test, w

From their website: "Consumer Reports tests hundreds of laptops each year, using identical procedures in highly controlled conditions. For the battery test, we download a series of 10 web pages sequentially, starting with the battery fully charged, and ending when the laptop shuts down. The web pages are stored on a server in our lab, and transmitted over a WiFi network set up specifically for this purpose. We conduct our battery tests using the computer’s default browser—Safari, in the case of the MacBook Pro laptops. During the tests, we set each laptop screen to remain on. We use an external meter to set the display brightness to 100 nits—a typical level you might use indoors or out. And, we turn off any automatic brightness adjustment in the laptop’s settings." While not explicit, it does seem to imply that they conduct the same test multiple times.