Since the voltage required to bridge the gap between the central electrode and the ground electrode of a spark plug can reach up to 40 000V and even more, my question is, how does the battery not die since the spark plug is grounded to it. Is all that energy lost in the ionization of the gas and thus the voltage reduced to ~12V?
- All current flows in a closed loop circuit.
- The ignition coil primary current flows from the battery through the coil and returns to the battery through the chassis circuit.
- The ignition coil secondary current flows from the ignition HT terminal through the spark plug, across the gap and returns to the ignition coil through the chassis circuit.