[2020] Riot, thank you for optimizing LoR's battery consumption on Android. Unlike TFT, I am getting solid playtime on my Pixel 3XL.

Thanks for the kind feedback - we have several heroes who really championed for mobile and helped everyone deliver the goods on phones; will make sure they see this!

Hi! I am one of the LoR engineers working on quality / performance / battery life. Thank you for playing LoR.

Battery life is pretty device and usage dependent. One of the biggest factors is screen brightness, but video quality does impact it quite a bit, too. Let me explain what the settings currently do, and try some rough estimates for play time on your Pixel 4 XL; sorry if it gets a bit long :)

• Starting from the top, "Ultra" is the highest quality setting: Native resolution, MSAA, and cinematic bloom on certain animations. This looks great, especially on tablets with larger screens, but is rather expensive. Luckily tablets tend to have big batteries to compensate for the battery draw to some extent.
• On "High" there is no MSAA, slightly less post processing effects, and the resolution is capped at 1080p. This tends to look pretty crisp on most phones, but especially text can feel a bit blurry on larger tablet screens. Battery consumption scales closely with the number of pixels displayed. On your Pixel 4XL with 1440 x 2960 native resolution this means 4.3M pixels in "Ultra" and 2.2M pixels in "High". Unless your phone runs at full brightness I wouldn't be surprised if "High" gets you close to 2x the playtime compared to "Ultra". If battery life is a concern I'd personally favor "High" over "Ultra".
• On "Medium" we turn off the parallax BG on the home-screen, lower the quality of dynamic shadows, and switch to a more optimized LODs for levelup animations and fancy spells. This is mainly intended to ensure smooth animations on older devices, but also helps a bit with playtime, though not that much, as we don't play those animations all the time. I'd estimate about 20% longer playtime on your device compared to "High".
  This is what I use on my (2.5 year old) personal device, as I value battery life a lot, and don't feel like miss out on visuals on the small screen. The trade-off might feel different and not be worth it for you.
• On "Low" we drop to 720p, turn off shadows, and lower all textures to half resolution. This is intended for even older devices with low amounts of RAM. The lower resolution extends playtime further, but not as much as going from "Ultra" to "High", as by now the core game-loop and the radios are the main energy consumers (beside display brightness). For your device I'd guess it would squeeze out another 20% longer play time. Unless you need that additional play time, I'd stick with medium to keep the higher resolution and the crisper text that comes with it.

Sorry for the long reply, I hope it helps. If you do end up experimenting with settings vs playtime, I'd be very interested in how your experience matches up with those estimates :). GLHF!