Samsung's Galaxy Z Fold 3 is a major step-up over the Galaxy Z Fold 2 thanks to a number of improvements and new features, like water resistance, an under-display camera, S Pen support, stronger design, and a brighter and more power-efficient folding display. The last part may not actually be as good as we thought, however, based on our experience with battery life on the Galaxy Z Fold 3, and we think the way Samsung's foldable phones handle display brightness is to blame.
The Galaxy Z Fold lineup uses separate ambient light sensors for the cover and main displays, and the main display's brightness is adjusted based on input from both those sensors. This is similar to how Samsung's regular flagship phones have ambient light sensors on the front and back for brightness control. As the experts at DisplayMate explain it, “your eyes are generally more adapted to the surrounding ambient light level that is behind and around the phone, which needs to be taken into account in setting the proper screen brightness.”
However, in our testing, we realized the Z Fold 3 seems to be giving a much higher priority to the cover display light sensor, which is driving up the main display's brightness even when it's not needed and resulting in high battery use as a result.
We're seeing battery drain of up to 10% with 30 minutes of use on max brightness, which is pretty disappointing considering Samsung's using a new power-efficient OLED panel for the phone. As we said in our 24-hours impressions article, the 100 mAh smaller battery could be part of the reason why battery life isn't great, and it's also possible that battery life will improve as we continue to use the device and it adjusts to our usage patterns.
Still, out of the box it's one of our biggest gripes with the Z Fold 3, and we really hope Samsung can make some improvements. Perhaps give us the option to disable the use of the cover display light sensor for brightness control on the main display? We're not sure what the solution would be, but fingers crossed the Z Fold 3 comes out flying in battery tests once we have used it for a longer period.
