Well, multiple capacity ratings do exist. The minimum rated capacity is based on an IEC Standard. Many of us discovered this the last time a similar discussion was held. See attached from the S20 Ultra settings. It matches what I stated.I've never heard of multiple capacity ratings. It's just the one design capacity.
If anyone wants to see what I'm talking about, open AccuBattery, then tap the menu button in the upper right, then tap the tutorial option. This runs you through the exact same process as when you first install the app (paid or free doesn't matter, and I'm not aware of a way to bypass this initial setup). When you swipe to the last page, you see the calibration page like in the screenshot I posted above. You can do this without losing any of your history or anything. If you have manually changed the design capacity, you'll get this result after the calibration. Notice how it states the capacity is set manually, whereas the earlier screenshot shows it was using a detected design capacity on a specific phone model.
As for how it detects the design capacity, my guess is there's an entry for that somewhere, possibly as part of the charging programming baked into the system.View attachment 320168
I dislike Accubattery anyway....I used it a few years ago and only reinstalled it for the last two discussions on this topic.