According to Android Authority the new Android could make battery health information visible to users
Android 14 exposes various battery health details to apps through new APIs, such as the manufacture date, cycle count, date of first use, charging policy, charging status and state of health.
The state of health is interesting as it estimates the battery's full charge capacity as a percentage of its rated capacity.
If a Pixel 8 battery's state of health is 90 per cent, it can hold about 4118mAh of charge (compared to the rated 4575mAh).
The Settings app does not show the battery state of health yet, but that is set to change soon, as the latest version of the Settings Services app (an extension to the Settings app on Pixel and other devices) found within Android 14 QPR2 Beta 2 has a new "battery health" page.
According to strings within the APK, this page will show you the "estimated percentage of charge the battery can currently hold compared to when it was new" (i.e. the state of health) before and after the "recalibration" of the battery. We do not know exactly what "recalibration" involves.
Still, one string suggests that the "process may take a few weeks", so we assume that it is simply the system collecting data over a longer period to provide a more accurate estimate of the battery capacity. The "initial battery health values" are "based on lab results" and might not be a good indicator of what your battery actually has.
The Settings app will offer "tips" to the user when the battery capacity is degraded or cannot be detected, so the user does not have to check the "battery health" page manually.
Google is working on exposing more battery-related information to the OS, such as the part status and the serial number. Android will support reading the battery's part status and serial number, provided the battery exposes that information to the OS and the vendor implements the new version of the Android health HAL.
The health HAL is the software that bridges the gap between the OS APIs that read battery/charging information and the software that controls the battery/charging chips.
Version 2.0 of the health HAL must be implemented to support all the new Android 14 battery health APIs like state of health, which is why so few devices support that.