Steam Deck Battery Life Tips for This Game
This is definitely a “your mileage may vary” post, but this is what works for me.
Set the graphics to the lowest except for textures on high and maybe TAA. I find that the differences between the highest and lowest presets aren’t really that apparent on the small screen.
Set resolution scale to ~85%. This does make the game blurrier, but I find at normal viewing distance it’s not too noticable, and the game is gonna look blurry thanks to the TAA no matter what you do. I do not recommend changing resolution scale if you plan on turning off anti-aliasing though, since there will be too much shimmering.
Cap refresh rate in Steam Overlay to 50hz–this keeps the game responsive enough, but I find it helps greatly with power consumption.
With all of these changes, I find you can easily get 3.5+ Hours on the Steam Deck.