The smartphone* only displays the battery level of connected Bluetooth devices in the following steps: Full, Half Full or Empty. The "Full" display appears between 100% and 95% of the actual charge level. If the charge level falls below 95%, the battery is already displayed as "Half-Full". (As of April 2019)
*Only for smartphones that support the function.
Tip: If you want to read out the battery level of a connected smartphone more precisely, you can use additional apps or widgets.