YouTube channel PhoneBuff compared the battery life of two iPhone Xs Max, with one running Dark Mode whenever applicable. Both devices had their brightness calibrated to 200 nits. The test involves having a bot keeping both devices occupied. You can watch the entire test below, as the phones go through iMessage, Twitter, YouTube and Google Maps. By the time the iPhone Xs Max ran out of juice, the one with Dark Mode still had an estimated 30% of battery left. This benefit is also not exclusive to the iPhone, and should apply to all phones using OLED displays. This is because areas on screen that are black are simply not lit, and dark areas are only dimly lit. LED displays, on the other hand, have even backlighting regardless of what’s on screen. That said, you should also not expect the same amount of battery life extension as demonstrated by PhoneBuff. In real use scenarios, your phone’s brightness will likely be changing depending on whether you’re using your phone indoors or outdoors. This battery life savings also hinge on the availability of Dark Mode in the apps you use. (Source: PhoneBuff / YouTube via Engadget)