As the new owner of a 2012 Fusion Hybrid in Michigan, I have been noticing the ICE running for increasing periods of time after I start the car in the morning, presumably in order to heat itself (as well as the catalyst, O2 sensor(s), etc) up. I have also noticed on a couple trips that the HVB state-of-charge as indicated on the dashboard has gotten very close (but not quite) to the "full" mark during this type of operation, and this makes me wonder: What happens if the HVB reaches 100% SoC (as shown on the dashboard) but the engine (or catalytic converter/etc) is still too cold?
In a conventional car with an automatic transmission, the excess energy produced by the engine when it is at idle and the car is stopped gets dissipated as heat in the torque converter of the transmission. But what happens to this energy in the FFH? I can't, at least off the top of my head, think of where it could go if not into the HVB.
Am I correct about that? If so, would the ICE stop running under such conditions? Or, would it keep running and continue to charge the HVB above "100%-as-indicated-on-the-dash" SoC?
Just curious, but I'm sure someone here will know.