Every time your iPhone’s battery hits 20%, you’re hit with a pop-up that asks if you want to enable Low Power Mode. For me, the answer is always yes, and thus I find it a bit annoying to tap that button every time. I solved this issue setting up an automation to turn Low Power Mode on without that extra tap.
To do the same on your own device, download Apple’s Shortcuts app and go to the Automation tab. Press the + button in the top-right corner and select Create Personal Automation.
Scroll to the bottom of the page and pick Battery Level and move the slider on-screen to the left until it’s at 20% (or at any other battery percentage you like). Select Falls Below from the list of options under the slider and tap Next.
Now tap Add Action and type Low Power Mode in the search box at the top. Select Set Low Power Mode from the list of actions and tap Next again. In the final step, disable Ask Before Running and tap Done. Now your iPhone will toggle on Low Power Mode automatically.