HV using EV capacity

John,
EV mode limits us to 62 mph before the PIP switched to HV mode because of high speed. Below 62, you can drive in EV as long as you don't go up to Power, where the ICE will start. And you can use EV until it goes to HV because of Low Battery.

In your test, you used the HV switch to go to HV Mode even though you had a Full Charge. With HV you get the Green/White HSI screen and you say the line is about 46 mph, above which the ICE starts.

What is the advantage of what you found in your test verses just leaving it in EV?

 

actually this morning while going down a hill i noticed that my speed had exceeded 62mph and yet RPM = 0, according to my scangauge. i guess if there is no power demand it will let you coast faster than 62mph. i thought that 62mph was the limit at which they had to start spinning the ICE due to the way the planetary gears are set up, but apparently not.

 

So the advantage is an Increase the total distance on a Full charge.

Depleting the battery in EV mode, THEN using the ICE as it switches to HV, can get us only so far. By using the ICE, and allowing it's initial Warmup, for an early level drive, instead of using EV, will save the battery when EV can be used and ready the ICE for when it's needed.

Is that it?

 

Presumably you want to avoid warming up the ICE, only to have it cool down before it is called on.

People will play their HV/EV games, and sometimes they will actually make a difference, but for most of the time I suggest a simple rule:

If the drive is > 13 miles then drive HV the entire way
If the drive is < 12 miles then shoot for EV the entire way; if the ICE is needed for acceleration or hill climbing then warm it up a mile or two earlier, during a moderate power demand phase.

 

Doesn't HV mode hold the SOC? If yes, then what is the point of the battery charge if you don't use it?

 

That would be news to me, but I do not have a PiP to say for sure either way.

 

I would say HV mode doesn't necessarily hold charge. It simply just isn't pure EV. So as John points out, in the green range, under 46 MPH, it behaves just like a no-plug Prius (please correct me if I'm wrong).

 

In effect, it's the same as having it in the EV mode (if driving under 46mph), right?

But if that speed is exceeded, then it runs with ICE (like regular Prius), but holding the traction battery charge.

I think, what you're all missing is a mode, which is configurable, where the blending starts. Now it starts at 62+mph, but you would want it to start at, let's say, 50mph. Am I right?

I think that EU version of PiP is like that. Normal EV mode works only to 51mpg. Above that, it starts to blend. But if EV City mode is selected, then blending start above 62mph.
At least that's how I understand this explanation:

Toyota Prius Plug-In | Toyota UK

Select Driving Modes.

 

This thread doesn't imply that anyone wants to change anything. John is simply pointing out his observation of how the PiP functions, and how it can operate like a regular Prius, when in HV mode. Long time Prius onwners like to exploit what the car can do, but have to understand how it is programmed to operate in order to do that.
The PiP brings the whole new concept of Charge Deplete and Charge Sustain, which is really the point here.
And how/when the PiP does it . These post are the documentation of that understanding.

 

Morning,

Never owning a Prius, and anticipating mine shortly, I find this thread and Paradox's methods completely fascinating.

I never had a car that allows such flexability and am looking forward to this.

I appreciate everyones input

Mike

 

A regular GenII Prius in HV mode start the gas engine for power demands more than ~11kW (~15hp). I assume it is still the same in GenIII and the PHV. PHV's EV mode raised the threshold to ~38kW (~50hp) before the gas engine is fired up.

So in HV mode, as long as the traffic/speed require less than 15hp, you can keep the gas engine off and it'll operate on the PHV battery using the EV miles. The reason is simple. The 1.8L Atkinson cycle ICE is not efficient when making less than 15hp (below ~1,000 rpm).

Here is what I think of the design. The 15hp battery threshold in HV mode was set to filter out inefficient gas engine operation. Likewise, the 50hp battery threshold in EV mode was set to filter out inefficient battery operation.

 

So then on the PiP, HV does nothing to change the parameters of heretical mode?

.

 

OK - please keep in mind that 1. I am NOT a rocket scientist or engineer; 2. I have NOT yet read the owner's manual (too busy having fun with my PiP); 3. I am on my 3rd Prius, although I never paid that much attention to the intricacies of my driving patterns in the other two: with that in mind, we took the PiP out this weekend and I have these observations:

when we are on the freeway and willing or compelled to drive below 62 mph, and I am in EV mode, I stay in ev and use the ev battery up at a fairly rapid pace;

when speeding up above 62, and reaching 65 to 70 mph, if I stayed in EV mode, the ICE kicks in, but the ev battery continued to deplete, only at an even faster rate;

if I turn off EV mode at 62 mph and switch to POWER mode at freeway speed, the ev battery held its charge and did not deplete until I returned to EV mode and took it out of POWER mode.

Does this make sense? Am I doing something wrong? I was trying to save the ev battery as much as possible for my <62 mph, street driving, where I could get the most bang for my buck.

 

In heretical mode, MG1 becomes the motor and MG2 the generator. This was done to keep the ICE at lower rpm. If the ICE is running, it should be the same as PSD gearing is the same.

The only difference would be that, ICE will run much less often below 62mph due to much higher battery power.

Above 62mph when ICE is running, it'll be mostly be in heretical mode (>15hp and higher speed), unless you are climbing hills.

 

I am not sure you can deduct this from the description given in the site (that in EV City mode blendig starts above 62 mph)

However, there are other interesting points in the description of EV City mode for the EU version:

1. Uses the HV and EV charge in the battery. Does this means it allows deeper DOD in EV City mode as compared to EV mode for the sake of longer EV distance?
2. Limited EV power to ensure maximum EV range.
3. Petrol engine engages only under hard acceleration.
These two are contradicting to each other. Maybe they simply mean different pedal mapping in EV City as compared to EV?
4. When battery depletes, the car automatically switches to HV mode. If point 1 above is as I understand it (deeper DOD) then you will pay now for the extra EV range, as the ICE will charge the battery up to the desired level for HV.

 

What is the 'typical' first minute MPG when the ICE comes on first time?

Does the PiP elminate the dreaded 'first minute blues' of the 3rd gen?

Example of first minute blues - 3rd gen 2011 Prius, 52 MPG on gage, 57F, light rain, residential area, 50 miles into the tankload ....

First minute MPG - about 10 to 15 MPG, brings average from 52 to 51.6 MPG in one minute ...

takes 10 more minutes to build MPG back up from 51.6 to 52 MPG.

Note - Engine block heater said to minimize above issue.

 

There are many different ways to drive the Prius. I had a 2006 and averaged as igh as 64.2 on one tank. My average in the Summer rarely dropped below 60 and in the winter never dropped below 55.
I got my pip 3 weeks ago. I'm still on my first tank with 800 miles so far and showing 109mpg. My commute is 31 miles each way and I'm currently only able to get a partial charge at work (typically 9 miles) due to timing. I typically drive for the first 5-6 miles in EV at just under 60, depending on traffic (I just got my stickers last night) and then switch to HV. While in HV at 65, my range goes up until I switch back to EV when I get closer to work. I have done a test twice to see how far I could get on the freeway from home with a full charge. I leave at 5:00 am so there is no traffic. I travel 1 mile on surface streets and then get on the freeway. I set the cruise control at 55 (to keep away from the 62 limit and for consistency with testing. It is very slightly up hill (about 1%) for the first 10 miles and then very slightly downhill. Without any regen, I've been able to travel 12.4 miles until the ICE kicks in. I still have full HV mode (the solid changes to bars) so if I slowed to 42, I'd be able to get another mile or so out of batteries. By the time I get to work, I've got about 2 miles showing of EV power so I use that once off the freeway.