Hello,
can you advise me on the correct settings for the BMV-700, because with these settings it always shows 100%, it doesn't matter if the batteries are at 14V, or at 12V during the winter, when I only have only 2 hours of sun a day.
BMV-700 settings 
Battery specifications
MPPT settings
MPPT settings 
Have you got everything electrically connected correctly? As in nothing on the negative side of the battery?
And then on the communication between components? Is it all through the Pi?
Yes i have correct connection, before shunt i have connected just 3 pir sensors. DC loads on raspberry pi show true current.
You have set battery capacity to 1800ah. The discharge recorded is too small to register in the % read out of the BMV.
Maybe check the battery size setting. 1800ah is a very big bank, especially at 12V.
But actual voltage is too low. It suggests the BMV is not correctly synchronising.
Also that the battery is not charging correctly.
I suggest you
Check/correct battery capacity in the BMV
Fully charge the battery
For safety, set equalisation voltage to the same as float.
