The Galaxy S8 and Galaxy S8 Plus come with support for fast battery charging, a feature that’s pretty much the norm on Android devices — the Galaxy S6 and S7 also had fast charging, as do most other flagships. However, just like its predecessors, the Galaxy S8 won’t use the feature in some circumstances, which means there’s a trick to ensuring that you’re fueling up the battery at top speed.
Testing the Galaxy S8’s fast charging feature, Phandroid discovered that the phone won’t always use fast charging even when the handset says fast charging is enabled on the screen. The Galaxy S8 took almost 3 hours to fully charge with the screen turned on, even if the phone showed the expected “Fast Charging” notification. The phone’s charging estimate was 97 minutes.
The site notes that other phones that ship with Fast Charging support make use of the technology while the screen is in use, whether it’s Quick Charge 2.0 (ZTE Blade V8 Pro), rapid charging (Google Pixel) or Dash Charge (OnePlus 3T).
The limitation isn’t mentioned anywhere in Samsung’s documentation, but it’s certainly a good thing to know if you plan on recharging your Galaxy S8 while using it. If battery life is critical, it’s clearly a good idea to turn off the screen while waiting for Samsung’s Fast Charging tech to do its trick, especially if you’re under any sort of time constraints.