Ignition switch power interruption from run to start

Bosch cube relay relay current is typically 0.11A at 12V that's about 1.3W. A Joule is a Watt second. A guess for required hold time is likely 50 to 150 ms. Using 100ms, requires at least 0.13J. Calculated number above in post 9 is much smaller.

Joule calculation is energy based, assuming discharge to 0V, but more is required to hold relay, perhaps 7V.