I concur with the Dr. This specific retard vehicle is very clever and has a really flash triple/quad battery configuration that switches batteries for startup or so that the instruments are operating off an independent power source and aren't drained or spiked by startup.
I only wish that Cirrus has thought of this which means you wouldn't have to sit on the taxiway waiting for the dreaded 30+ second countdown!
+1 to Jaba for his ingenuity in this area of an otherwise retarded aircraft.