I have noticed on my EC-130 that if I for example turn on Direct Battery before I turn on External Batt/Pwr in the start up sequence I will, upon shut down, get a failure detected. It spits out some erroneous reason similar to what you are finding. The only reason why I would turn Direct Battery on before External Batt/Pwr as called for in the start up check list would be for a night flight where I am turning on the Dome lights of the cabin for loading pax. The VEMD's are famous for showing goofy failures sometimes. Although mine is flawless when the checklist is followed...I bet you will find a reason as to why it does what it does.
Good luck.