Leisure battery charge level

[Lequimper]

It looks like when you are trying to check how much charge you have in your leisure batteries on the overhead screen the most accurate information is the number in volts to the right of the van picture rather than what the blue bars show? On my 6.1 the blue bars aren’t really consistent with the number so appear to give only a rough estimate which rather makes me wonder what the point of them is apart from a colourful picture??

Or is there a different explanation? TIA.