I do not own an RXV, maybe someday when RXV folks buy new ones I can get an older one to work on

.
It is interesting about the brake, never thought of that. Makes me wonder how they push them around the factory before batteries are put in....
My Dad owns a IQ Club Car with tow mode. We did not just leave it in tow mode, we disconnected the pack completly from any components to remove any parasite drain.
I assume the same could be done to the RXV (assume being the operative word).
That said, the more we read, the more we know that batteries begin to sulfate when left uncharged. If you want to extend the life of the pack it is highly recommend getting a Battery Minder or some other product for the times you are away.
Just one article about battery care, see #8. There are many many more...
BatteryStuff Articles | Guide to Understanding Flooded, AGM, and Gel Batteries