Warm up?

Agreed.
I've noticed two speed thresholds that seem to fire up the ICE in cold temps- 23mph and mid 30's mph. Once you burn off some initial EV miles from the driveway you can exceed 23mph, burn off a bit more and you can exceed mid 30's mph.

 

You also have to remember that the PIP is first gen Toyota Plug-in Hybrid Electric Vehicle tech (even though the it's in a gen III Prius vehicle).
Maybe Toyota will learn what makes us PIP owners unhappy and address in their next PHEV...

 

Absolutely. Gen1 Prius had belt driven AC. If you turned on AC at stop light, ICE would come on.

It wasn't until Gen2, electric AC was introduced. You can expect incremental improvement from Toyota. Low hanging fruit first then move up higher.

 

euro model may vary.

 

Now it would appear that we have talked around in a circle.
WHY is the threshold 10 MPH ?
What possible reason could there be for that ??

 

The same answer. Battery life.

The higher the speed, the more power and energy it will need from the battery for both accelerating to and maintaining that speed. Plus, regen and cycle repeats.

In another word, more stress on the battery. The deeper the cycle, the lower battery life for NiMh. BMS limits the usable SOC between 40% and 80% but you can potentially cycle all the usable 40% fairly quickly because you want to climb hill at 34 mph on battery. That's why EV speed has a limit.

PiP with much bigger battery was designed to handle speed up to 62 mph with 38kW power available to accelerate and cruise.

 

they had to pick something.

 

Sorry but I don't buy that explanation for two reasons:

The system itself will allow that to happen so it obviously is able to monitor
the actual important parameters and act accordingly.

And the battery is there TO BE USED.
"Saving the battery" is not the primary concern......or it shouldn't be.
Saving gas is the objective.

Speculating about the reasons is often interesting but I think we've about played that out.
My original question was: "I'd like to hear from Toyota why they did that."
That still applies.

 

Perhaps this would help. It is not from Toyota so, you can just ignore it. But I will say this. A typical hybrid cycle on battery is 5% depth of discharge. The way you want to use (EV cycle) is 40% depth of discharge (dod). Prius battery was designed for hybrid, not EV.

40% dod can happen in very heavy traffic and it is reserved for those atypical conditions.

Understanding NiMH hypercycles (to prolong Prius HV battery life) | PriusChat

 

Then why have the button at all ??

 

So you can use it / prevent ICE from starting when conditions allow.

Not sure about c but 95% of the time, I was able to enter EV mode in my Gen2. How often are you able to enter EV mode?

Don't shutdown with 3-4 bars left on the battery. Normal is 6 bars. These bars are not linear.



If the temp is too cold, there is not much you can do about it.

 

I give up.
It appears that you aren't listening.
Your answers are good......but for the wrong question.

My ONLY question/complaint is with the 10 MPH "speed limit".

I have no problem entering EV mode with the button; it only took me one day
to figure out what (most) of the restrictions are .....because it TELLS YOU.

The other restrictions make perfect sense; the 10 MPH one does not.

 

the gen II prius did not have the ev button in the u.s., there had to be a reason for that. there was much complaining and pressure on toyota since they had it in japan and europe. in the meantime, people figured out how to hack the system and add a button. then, many figured out the button was almost useless. then they added the button to the gen III, and many more found out it was (almost) useless. toyota may have been right 10 years ago.

 

I answered it already. EV mode allows more power from battery but limits the speed.

HV mode allows higher speed but limits the power. Remaining power is filled by the gas engine (off load battery stress). When you accelerate to 35 mph, gas engine will likely fire up.

It all comes down to the depth of discharge and battery stress. You discharge it fast, you get lower duration (hence lower speed).

I give up too.

 

if the ev button allowed you to drive X feet under 5 mph, without the ice starting, based on soc so you could move the car from one spot to another, and allowed you to drive upto X mph based on soc and temp, etc., it would be useful. but apparently, that cannot be done. that's how some of us wound up in a pip.

 

An engaging conversation.

 

Your right engaging is the problem!

 

You bet it is...by Toyota.
They are going out of their ways to prevent some reckless driver (not you) from abusing the battery and get a replacement at no charge as a reword.

 

Then why don't you ask them?

 

And we found out the PIP has some very quirky limitations on it's battery use too
We have to assume Toyota knows best here- and without a doubt is being cautious and conservative with it's batteries because of longevity and warranty concerns.