Hi Joerg,
I don't want to annoy you but how long is the warranty on your installation? This whole "do leave the batteries at 100% for extended periods" is to preserve the batteries in 5-8 years time, not next year. So unless you get 10 years of warranty for more then 80% of the original capacity, they can say whatever they want.
My point is that I have a hard time believing these batteries will last for such a long time. And even Tesla with their 8 year warranty tells you to refrain from keeping the batteries at 100% SOC. They do have some experience in this field, more then Mastervolt for sure.
Regards,
Arno Luijten
SV Luna,
A54-121