Prius Prime Regeneration Braking Efficiency Experiment

welcome, beautiful!

 

Its cool how you calculated this. What is interesting is the prime charged to 100% at the bottom of the hill, so the prime will not accept any more charge and brakes will absorb the excess energy. If you drained the battery at the top you could of potentially gotten an even larger charge increasing the regen efficiency. Great MPG

 

What was you EV to HV ratio?

 

Great information!

 

stickied!

 

If you do not want to use the ICE just switch back to "D" before stopping or accelerating.
For an explanation of "B" mode Go to wiki books and search the following - Toyota Prius/Driving tricks

 

Nice to know that you can regenerate like that. One question is suppose you deplete the battery in EV and switch to HV and start going down a mountain where you can regenerate a lot, say 3kW or enough to be able to gain a good bit of EV range, would you be able to enter EV mode again? I think this was something the Volt cannot do (I watched a video of Volt owner shutting his car off to restart it to be able to use EV mode after regenerating down a mountain).

 

The answer for Prime is that after regenerating awhile the car showes between 1 and 2 miles of EV available and at that time EV driving is available. It may automatically switch to EV driving at that time.

 

will absorb the excess energy. If you drained the battery at the top you could of potentially gotten an even larger charge increasing the regen efficiency. Great MPG

 

Thanks for info))

I fount info what I needed

I would like to know feedback about Toyta Camry LE

 

сool

 

Excellent data. Thank you for posting it.

It is worth keeping in mind that the calculations ignore parasitic losses. When ever a vehicle coasts (uphill, downhill or on level ground), it losses significant energy to aero drag and rolling resistance. That energy is gone and cannot be recaptured by regen.

Actual wheels to battery efficiency is probably close to motor efficiency, so 70-80%?

 

Subscribed! I love this kind of stuff...the nerd in us!

Thank you for sharing this!

 

On my daily return, the car is low on charge, I have on petty good series of upgrades, so I charge to somewhere between 15-20 mpg, use most of that until the last peak. At the light I start charging again, conservatively until the actual downhill roll starts. At that point I use either drive or Brake. Both positions
provide very small, even non existent ICE usage and gravity charges most of that portion until the bottom of the American River canyon. All basically Brake charging. The EV use is generally 65-69% Now the uphill starts, a more dangerous portion so my average speed is definite less than 30 MPH. Until the next peak, then it’s EV for the rest of the commute. I generally make it home with 5-9 miles left. I consider that a failure, I’d rather run out at my driveway. Well, next time ... maybe.

 

I can take a rough cut at showing that, based on amperage required to drive a steady 55 MPH on level highway. I estimate that to be 35 amps, using a Scangauge, Presumably, that's the frictional losses when driving at 55 MPH, plus motor/inverter losses.

From that, I can adjust out the friction losses, like so, for an assumed 55 MPH or (guesstimated) 65 MPH 8 mile trip:



And it's exactly as you said. If the motors are about 80% efficient, and you lose about 10% of the energy when you charge the battery (per https://fueleconomy.gov/feg/atv-ev.shtml), you ought to see about 70% of potentially recoverable energy end up in the battery. And that's just about how it all works out, starting from an observed 35 amps to keep the car moving along steadily at 55 MPH.