Why does macOS estimate battery percentage higher? Why do you think the OS estimates a battery percentage a little above the actual value? I noticed it is always between 0% and 5% more. In particular the two percentage gets closer when the remaining battery gets lower. Maybe this way the device seems to get faster to 100%, since the 95%-100% takes a lot of time...?

Some details. I can find the percentage two ways:


From the battery menu bar icon or with pmset -g batt (eg. now they say 96%)
By calculating it manually from System Information.app or with information from ioreg -l -n AppleSmartBattery -r (eg. now I get: MaxCapacity: 4181, CurrentCapacity: 3813; meaning 91.2%)
My guess is that with AppleSmartBattery, you are calculating the percentage based on the batteries brand new, fully charged state. Whereas the OS is basing the percentage on what the battery is currently capable of at full charge, which will slowly degrade over time.