My main big battery does not hold a charge. It can be almost fully charged at night and the next morning its way low. Bad battery possibly? It seems when I am in EV mode it drains pretty rapidly but I don't have anything to compare it to.
I totally agree with GrySql that doesn't sound right at all.
For me my HVB SOC is usually slightly higher in morning than when a shut it off the night before. In afternoon when leaving work the SOC is quite a bit higher it seems the HVB "relaxes" a bit remembering the true SOC while waiting for me to finish work.
How is your 12V battery? Maybe the HVB relay is not getting disconnected after shut down and now draining the HVB.