Yep, I stay within 30%-91% where possible, and also limit the charge current to 500mA since the device defaults to 2.7A which I think is a bit high...

As @airbussy@lemmy.one mentioned it's probably in the settings menu for your device if you've got a newer phone.

On the FP3, the phone's hardware supports it, but it's not implemented anywhere in the settings sadly - only way to access it is by rooting