Regen/Acceleration/Braking Paradox?

doesn't yours have hill stop assist? try pressing hard on the brake until it beeps, then let go.

 

Even before the erroneous (to deceptive) Unintended Acceleration reports several years ago, Prius brakes suppressed accelerator activity.
I have never wanted to depress the brakes and the accelerator, so I have no first hand experience. (for as far as 150 miles, there is no elevation change near me)

 

Seeing that the accelerator/throttle control is all "by wire" anyway, it's not even really that the car "overrides" your accelerator input ... it's just a matter of the designers sort of deciding what an input combination like that ought to even mean, so that it would be useful without being very surprising to anyone, and what they chose (at least in Gen 1, and I think it's still true later) was to make that a "force charge" mode.

You've probably noticed any time you play with the accelerator pedal in a state (like Park or Neutral) when the car doesn't have any use for more power, pushing the pedal doesn't directly rev the engine, but it does act as if you're gently hinting to the Prius that for some reason of your own you wouldn't mind the RPMs going up slightly if it's not too much trouble, and the car will sort of humor your suggestion up to 2 or 3,000 rpm or so. If you happen to do that while in Drive and with your foot on the brake, the car will raise the engine power output slightly and send the excess to the battery, as long as the battery has capacity for it. It's like what they say about hypnosis: you won't ever really force the car to do anything it strongly objects to, but if all you're asking is something the car hadn't planned to do on its own but doesn't otherwise object to, then it will.

Right - you never fool physics, so the total kWh added to the battery during a force-charge will always be strictly less than the kWh of fuel burned to do it.

-Chap