How much energy is actually regenerated?

2013 model here. I recently drove a 400 mile trip where I 'saved' most of my EV miles for the end of the trip where I expected to hit traffic. This meant I had about 8 miles rated EV displayed for most of the trip. With much of the trip rolling hills, I was able to regularly regen to 10 miles or so. If I switched to EV while at 10 miles, then back to HV, it did not use 10 miles as the new set point. It always used up those miles in HV mode and I arrived in the destination city with about 8 miles of EV.

Was this above the 75% magic number or something?

 

This is how I "trick" the PiP into getting over 100 mpg on a 45 mile commute with only one charge (and why my estimated EV range when starting is at 21.4 miles). I always switch to EV mode when going downhill or braking. I accumulate the EV range and use it on parts of the commute where there's slow, but steady traffic. I can build up an extra 5 - 7 miles of range this way. If I just drive it without thinking about anything I can only get about 80 mpg on the same commute.

 

And I did check. Going downhill at 50 mph, the regen area of the HSI 80% full, there was no friction braking but lots of nice regen.

 

The 80% is about the HSI display not anything to do with efficiency. The "experiment" was to see if the friction brakes came on which they didn't. They only seem to be engaged in a near panic stop, like the gas guzzlers use most of the time.

 

And the regeneration on the PiP can absorb more power than the standard Prius, due to higher capacity components and the LiIon battery chemistry.

 

But it could be converted to mirowave to powerup the photon torpedoes.
A few weeks ago I noticed while going across a millon year old dried up river bed that is about a mile wide I guess, that in ev, coasting down one side I gain 1/10 mi ev range. Getting up the other side I loose 1 mi ev range
Not sure if that helps or complicates things more.