It would be great if you could plug in before your return to the summit. However, because you make this same journey frequently, you'll learn how much charge is needed for a comfortable return to the top.
Now to my personal quest: I've been very interested in what happens when someone who lives near the summit of a mountain descends in their fully charged Clarity PHEV while applying the car's pseudo engine braking. You, jpkik96, are the Clarity driver I've been hoping would join this forum because you can begin a descent with a fully charged battery.
Pseudo engine braking occurs when the Clarity uses its traction motor as a generator to decelerate (or resist gravity-induced acceleration). Normally, the electricity generated by the traction motor functioning as a generator goes to the battery pack. However, if the battery pack is fully charged, the Clarity must find some way to "burn off" the electricity generated by the traction motor. The Accord Hybrid burns off excess electricity by using the starter motor/generator as a motor to spin the engine, but the engine does not receive fuel so it does not start up. The pumping of air through the unfueled engine provides the resistance to use up the excess electricity. It's unclear if this is what happens in the Clarity PHEV.
When you descend from the summit with a fully charged battery and let off the accelerator pedal, what happens? Does the engine start up and continue running all the way down? You could detect this by the illumination of the engine icon at the top of the Vehicle Energy display. I don't understand how a running engine could produce much resistance to the starter motor/generator.
Or does the engine start up and run just part-way down the mountain? While I don't understand how the running engine helps burn up excess electricity, it could be that the engineers want to run the engine to warm up the oil before cutting off the fuel to the engine for the remainder of the descent.
Or does the engine NOT start up at all as you descend from the summit? What does the animated energy flow diagram on the Vehicle Energy display show you? It shouldn't be showing energy going from engine to the battery or to the wheels. Does it instead show energy going from the wheels TO the engine?
jpkik96, only you of all the people on this forum are in a position to answer my burning questions. Your findings may provide a repeatable way to explain why some Clarity drivers on this forum experience unexpected engine activation shortly after setting out with a fully charged battery--usually when applying the brakes.
