Google recently added a new feature to Pixel smartphones that aims to preserve battery health by restricting charging in certain situations. Google is expanding this limit in Android 12 so that your Pixel will stop charging if it gets too hot. When the phone has been on a charger, whether wired or wireless, for an extended period of time, about four days, Google Pixel Phones will automatically cease charging and limit battery capacity to 80%.
What these strings don’t reveal, though, is how Google restricts charging. It’s possible that this may result in the same 80 percent cap as before, but it’s more likely that Google will cut down its billing rate. In fact, the term “slow charging” is referenced on the linked page, so it’s plausible that this behaviour already existed and Google is only now providing a visual message for it. It’s unclear whether this update will also affect prior Android versions.