Low battery - the number of keys that have a battery charge below 30%. The battery charge is updated when the key is connected to the server. If there has been no connection for a long time, then the charge data will not be relevant.
Device error - the number of HK that went into the error state.
License expired - number of HKs whose license has expired.
Registered - the number of HKs that are registered on the server.
In reserve - the number of HKs that are registered on the server, but are not tied to specific users.