So I've asked before and got no response, but I think I'd like to try this again.

On my #Android phone (currently using GrapheneOS) after some period of time (I think something like ten days?) sitting on the charger it starts limiting the charge to ≈80% to better protect the battery. That's great. But it's almost impossible to get it to actually do it and it means I have to always be afraid to have my phone off the charger too long because if it drops a single percent while off the charger it resets the counter and goes back to 100% until those ten days or whatever.

I do have root access. Is there any way I can just force it to simply always limit to 80%? That's better for the battery long term and I don't need a 100% charge.