What does the value 0 mean? The same as unknown?
I have also received 9 and 10, but they are not documented.
I assume that such values as 9,10 and 12 can also "appear" as
combinations with 1+8 / 2+8 / 4+8,
i.e. state high + charging, low + charging and critical + charging.
If so, You should mentioned it in the manual.