Archives

NiMH equipped Prius-II OEM PHEV-6 is a winner. Prius-III w/ NiMH by late 08/early 09 and Li-Ion later. (http://www.cleanmpg.com/forums/showthread.php?p=65408)

http://www.cleanmpg.com/photos/data/590/Prius-II_OEM_PHEV_Drivers_Side_Profile.jpgWayne Gerdes - CleanMPG (www.CleanMPGg.com) - Jan. 16, 2008

Detroit, MI. -- With the advent of GM’s Chevrolet Volt concept at last year's 2007 Detroit Autoshow, the Prius faithful held their collective breath waiting to see what Toyota would offer to counter the uber-capable but paper launched GM PHEV. Toyota did come through -- though with some twists.

Just seven short months after the appearance of what is perceived to be direct competition, Toyota reversed a multi-years long anti-PHEV stance and revealed some of its cards in this high stake automotive poker game.

The Prius nation was introduced to an inspiring current generation Prius-II augmented by an additional NiMH pack, charging port and new SW programming yielding modest AER capabilities. Most in the hybrid community now wonder why this OEM PHEV was not released earlier.

This is Toyota’s first real world PHEV, and it ushers in a new era of clean transportation from the most successful of hybrid manufacturers.

Minor tweaks yield large improvements

Toyota has created a game changing vehicle by adding a second NiMH pack (identical in every way to one currently housed in the standard Prius) to the space normally reserved for the spare tire. New SW/HW programming allows EV mode up to 62 mph (21mph faster than the stock Prius!) and a smart charger can be used for plug-in capability. Although the smallish 1.3kWh pack may not seem like a large addition, two packs connected in parallel reduce current draw and inrush by half, allowing a deeper discharge without harming pack longevity. With more current and a slightly deeper discharge available, more power can be applied to the EV power plant commonly known as MG2.

What these minor additions provide is not only much improved performance in any number of driving scenarios; it adds the ability to travel 6 + miles on electricity from a household outlet. With more current available to MG2, faster accelerations and higher speeds are achievable in EV mode.

While the benefits of a plug-in are numerous, primary among them is the compelling fact that electricity to drive the Prius-II PHEV requires just ¼ the cost of traveling the same 6 + miles using gasoline!

Look and Feel

http://www.cleanmpg.com/photos/data/590/Prius-II_OEM_PHEV_Consumption_Screen.jpghttp://www.cleanmpg.com/photos/data/590/Prius-II_OEM_PHEV_Energy_Screen.jpghttp://www.cleanmpg.com/photos/data/590/Prius-II_OEM_PHEV_Plug-in_Screen.jpg
Energy Screen--------------------------------------------Consumption Screen-------------------------------------------PHEV Screen

The first screen on the left is the standard Energy screen. What is added is the bar graph and EV remaining text. As long as you keep the blue bar from rising into the red, you can stay in EV running off the pack. EV remaining is self explanatory.

The center screenshot is the standard Consumption screen although 1 minute bars like the TCH are included vs. 5-minute bars in the standard Prius. The 33.1 mpg does not make any sense but I suspect Toyota was charging this PHEV off the ICE between driver schedules.

The left screenshot is a new Plug-In screen showing power input into the pack on the last charge and cumulative over the last month. No explanation as to the meaning of the EV/HV bar graph at the bottom was available.

http://www.cleanmpg.com/photos/data/590/Prius-II_OEM_PHEV_46_mph_EV_News_1.jpg
46 mph EV

The screenshot above included both the speedometer and Energy screen showing > 41 mph EV mode in real time. Besides an up to 62 mph EV mode, you have available to you a pure glide below 63 mph as well. I do not know if there is a warp-stealth capability above 62 given we did not travel above 52 mph during the segment.

All in all, with temperatures in the lower 30’s and 5.4 miles of EV capability per the Energy screen when first driving off, we drove 5.x miles with .5 miles of ICE-On time. Arriving back at the initial start point showed a spare 1.8 miles of EV left in an OEM setup vehicle. For a hypermiler in a well setup PHEV, I suspect the OEM PHEV-6 (PHEV-8 on the Japan 10/15) could be taken out beyond 10 miles from a topped off pack to a completely depleted one without much effort other than knowing how to handle a Prius in various traffic conditions with the various standard modes available.

The subheading for this thread is: NiMH equipped Prius-II OEM PHEV-6 is a winner. Prius-III w/ NiMH by late 08/early 09 and Li-Ion later.

Any details on the second half of that, or is it just a teaser? :-)

Thanks for the detailed description of the PHEV. That's great!

http://www.popwink.com/wp-content/uploads/2007/08/homer%20drooling.jpg

Wayne,

When will they be available and will they retrofit existing cars.

If they can retrofit, double my previous post. :D

Forgive my ignorance, but what is the "6" in PHEV-6?

Any hint of a price tage?

My commute would be all EV round trip instead of just getting the engine warm twice a day! And it is off the charts running errands. What sort of highway improvement might one expect? I'm thinking not much highway improvement, since carrying more weight and still getting all the energy from gas. Also, they'll have to beef it up a bit to maintain a reasonable cargo capacity, yes?

Great news!

Jim, the "6" is for 6mi AER. A good hypermiler should get around 10mi out of the pack according to Wayne. Based on prices, we are guessing maybe a $2.5K upcharge for this? WAY WAY WAY cheaper than any conversion currently out there and though the range will be less than other offerings with the NiMH, as soon as they switch to LiON the benefits are multiplied by a large margin. :D

Wayne and Blake actually drove it at lower highway speeds -- no issues! I expect you'd use the pack a bit faster at high speeds but you have full EV at higher speeds with more tolerance for heavier acceleration rates. VERY nice improvements all the way around!

Anyone have an idea what happens when the AER is gone in terms of the SoC range the computer operates in? Or what percent charge it tries to maintain?

Great article guys, thank you!

I have a question.

Are the glide capabilities extended to 62mph? This may have been mentioned before, but I missed it. Can I take her on the highway and "IGN18" up to 62, then GLIDE down to 55, for example? If the answer is yes, then insert my own Skwyre7 Homer photo here. :)

So let's see. My 23 mile RT commute means ~5750 miles a year. If I average 75mpg, that's ~77 gallons a year commuting. @$3.50/gallon, that's about $268/year.

Let's say I can avoid gas on my commute (11.5 each way......pretty close to 10.....we'll see). At 1/4th the cost of gas, I'll be paying ~$67/year in kWh for commuting. That's a net savings of $201/year. I'll recoup the full $2500 in year 12. And commuting is only about 1/3rd of my annual driving.

Sign me up. :)

Marc, according to Wayne the standard capabilities available on the stock Prius for gliding under 41mph are all available up to 62mph in this implementation. Plus, you can accelerate harder without pulling the gas engine online. :D

I guess you are getting signed up, huh? ;)

OOOooooh BOY! HERE COME THE JUDGE!!

I really like the EV bar graph and EV remaining display. They should put that in all their hybrids. I have tried driving my parents' Highlander Hybrid and it is much harder to stay in EV than I ever imagined it would be. That display would be incredibly helpful.

I want one too! Hopefully existing vehicles can be upgraded.

oh man, I want one so bad... anyone want to by an only slightly used Altima?

-Gren

Wayne,

Can you setup a group buy for us???????????

If they ever release those that's when I trade in my car.

I don't even need the battery. Just give me the 100kph glide.

I don't even need the battery. Just give me the 100kph glide.

Interesting perspective. I need the battery for in-town driving. Would highway mileage be better if some or all of the extra battery could be removed for longer and/or higher speed freeway trips? There is still conversion loss to get power in the pack...

Curious if anyone cares to guess what the city and highway EPA ratings for this -6 configuration might be. EPA won't be hypermiling or plugging in to re-charge, so won't the highway mileage be slightly less than Prius-II due to weight, but maybe they get a little more out of the city tests? Steady-state freeway mileage has to go down, right?

Also, what sort of hypermiled city and highway mileage might this setup allow? 100+ in town? 80+ highway at 62mph and below?

I don't even need the battery. Just give me the 100kph glide.

That would be great also. Maybe some of us could be a test bed for the new screen. We could give them feedback.

I should clarify: When I said "battery" I really meant "plug-in battery." I'd like to keep the battery that's already there.

Interesting perspective. I need the battery for in-town driving. Would highway mileage be better if some or all of the extra battery could be removed for longer and/or higher speed freeway trips? There is still conversion loss to get power in the pack...

Curious if anyone cares to guess what the city and highway EPA ratings for this -6 configuration might be. EPA won't be hypermiling or plugging in to re-charge, so won't the highway mileage be slightly less than Prius-II due to weight, but maybe they get a little more out of the city tests? Steady-state freeway mileage has to go down, right?

Also, what sort of hypermiled city and highway mileage might this setup allow? 100+ in town? 80+ highway at 62mph and below?

My thoughts were the same as Brick's initially. Just give me that glide. But then I started thinking about all of those Prius purchasers who get on Priuschat and say "I only get 35mpg, and yes all my driving is short trips". A mere PHEV-6 might not end gas entirely for most commutes, but boy will it help the short trip syndrome a lot.

My guess is that highway EPA would be better at all speeds, and not worse at any. If I were designing the thing, I would leave the "mimic" exactly where it is (around 65% SOC currently, much lower with two packs), and program the computer to bleed (assist) any excess charge until that mimic level is reached. What that means in practical terms is that you'd have two full packs in the morning, you'd get on the highway, and you'd have 6 miles of grid-generated pack assist of the ICE on the highway, which would get you iMPG in Insight territory for a while.

When you reached the current mimic level, assist would end and the computer would maintain that level on the highway (65% SOC) with the arrows flashing back and forth between assist and powering up the pack. Then iMPG would fall back down to more Prius like levels.

If you didn't keep the mimic where it currently is, then a long highway trip without an overnight grid charge would fill, and fill, and fill, and fill up that pack. And that's no good. I don't want gas filling up two packs. I'd rather fill it up from the grid when I get to my destination.

If this doesn't make a lick of sense, let me know and I'll take another stab at it.

Thanks mparrish.

Won't the EPA conduct it's tests such that SoC is the same at beginning and end? If so, where does the mpg bump come from in steady mph above 62? Or even steady mph below 62? I know the folks here will drive smarter, but where will the EPA get better highway results? We know the extra weight pulls it down, but where is the offset for them? Certainly they get some back from regen at exits and stops, but I'm thinking that can't offset the extra weight in longer trips.

Also, wouldn't you want to have the pack just get enough recharge to assist on climbs and to run AC and other accessories in steady state highway driving? (I'm ignoring the initial 6-10 miles of pack benefit from charging in the garage, like I'm starting from the hotel parking lot on vacation.) I'd think you want the gas going straight to the highway to minimize conversion losses.

I just think the world at large may yawn because it cannot beat the P-II under highway cruise control. (I'll buy mine before they "get it.") But man, in town and stop and go this thing ought to be spectacular.

ksstathead, these are great questions. And the most important thing for me to point out is that I don't know the answers :). I honestly don't know much about the details of the EPA tests themselves. I bet others here do. But it's worthwhile and fun to talk them out.


Won't the EPA conduct it's tests such that SoC is the same at beginning and end? If so, where does the mpg bump come from in steady mph above 62? Or even steady mph below 62? I know the folks here will drive smarter, but where will the EPA get better highway results? We know the extra weight pulls it down, but where is the offset for them? Certainly they get some back from regen at exits and stops, but I'm thinking that can't offset the extra weight in longer trips.


You are most likely right. If you bought this plug-in Prius and never plugged it in, your highway MPG at any speed would be slightly lower because of additional weight. It leads to all kinda of interesting questions. How does the EPA account for a second, additional fuel source that is both cheaper and optional? Do they publish two sets of ratings? One assuming no use of the optional source, and one assuming daily use? That seems like a good "truth in advertising" solution to me. So maybe the Prius on the highway goes from 45mpg to 43mpg (no charge) / 60mpg (daily charge) assuming a fixed number of highway miles driven. Also, charging ain't free. Should daily use kWh be converted into a mpg-equivalent? I'd say yes. Either that, or your new EPA ratings are 43mpg/0mpkWh (no charge) / 43mpg/17mpkWh or something. Now my head hurts. Those EPA ratings are completely unhelpful to the typical consumer.


Also, wouldn't you want to have the pack just get enough recharge to assist on climbs and to run AC and other accessories in steady state highway driving? (I'm ignoring the initial 6-10 miles of pack benefit from charging in the garage, like I'm starting from the hotel parking lot on vacation.) I'd think you want the gas going straight to the highway to minimize conversion losses.

Yes. Once the initial 6-10 miles of grid charging is exhausted, I'm assuming the plug-in would operate just as any Prius today...maintaining (bleeding & charging) a steady SOC as needed for climbs and electronics and such.


I just think the world at large may yawn because it cannot beat the P-II under highway cruise control. (I'll buy mine before they "get it.") But man, in town and stop and go this thing ought to be spectacular.

I think in the end the EPA has to at least publicize a likely improvement in "miles per fuel cost" in some easy to understand manner assuming one plug-in per day and a typical number of highway miles driven. That may not be all that should be publicized, and I bet there's a lot of debate how it's done. But I kinda like converting kWh to an mpg-equivalent and then advertising "60mpg-equivalent highway assuming one full daily charge". For the EPA to not take it into account seems almost deceitful.

Yeah, she would be absolutely awesome in the city. At the same time though, as a hypermiler it's the highway that has me excited about these developments. Gliding up to 62mph will of course kick butt. But in addition to that most of us have our 10 mile highway trips from time to time and like many I know I can stretch that 6 miles of charge out to maintain Insight-like highway performance for most of my highway driving needs within the city.

If you didn't keep the mimic where it currently is, then a long highway trip without an overnight grid charge would fill, and fill, and fill, and fill up that pack. And that's no good. I don't want gas filling up two packs. I'd rather fill it up from the grid when I get to my destination.


My thought would be you would change the 40-80% range to the lower bound of the 2 pack SoC range + 20% when the pack is depleted.

So if the double pack SoC range is 10-90%, once the pack reached 10% it goes into normal operation between 10-30%, trying to hold ~22% until you plug in. Or have it go into normal at 22%. I think we're saying the same thing, but I'm thinking a lower mimic level with a smaller range.

Hi Ron3Kl:

___2009 is when the Prius-III w/ NiMH’s arrive. It will have all the capabilities of the Prius-II PHEV-6 minus the plug-in and larger pack. 2010 comes a Li-Ion HEV. 2010/2011 comes the plug-in. Engineers and managers on the ground hinted at complete swap ability between the NiMH’s and later Li-Ion’s but like anything else, plans do in fact change.

___Bestmapman, only if you can get a hold of that flash and SW upgrades to the new screen additions by all appearances :(

___JimboK, PHEV-6 means 6 miles or AER on the EPA’s city/highway tests. Real world for us, a lot more ;)

___Ksstathead, the warm-up hit for those really short commutes disappear altogether! If your speeds are under 34 mph, any conversion would allow no fuel use up to the packs cap. About the highway FE. Because you can now glide from 62 on down, you bet their would be a benefit on the highway. You have to come to a stop or are coming down hill at some point and when you do, the newly added capability would really help. Add the ability to really P&G at highway speeds and this thing could really kick @$$!

___WRT the FE tests, both Toyota and Honda are way ahead of most when it comes to the EPA PHEV and FCV testing and are helping write the FE rules for a future PHEV mpg equivalent.

___Sup’d, it appears that there is more range of SoC given the miles of AER added with a doubling of the pack. Once the bottom has been reached, it does everything a standard Prius is capable of. I am not sure of exact SoC but was simply told it will act similar to a regular Prius once the pack has been depleted. I doubt 10% on the boom is the target but I suspect maybe 25 to 30% is?

___Mparrish, yup :D

___Ed, if there is ever a Group Buy capability, you bet :)

___Good Luck

___Wayne

Hi Ron3Kl:

___2009 is when the Prius-III w/ NiMH’s arrive. It will have all the capabilities of the Prius-II PHEV-6 minus the plug-in and larger pack. 2010 comes a Li-Ion HEV. 2010/2011 comes the plug-in.

Wayne,

Thanks for the update. So what does the 2009 Prius-III add? The extra MFD displays? An EV button? (It's not PHEV and has the same pack...) EDIT: AHHH! HIGH SPEED GLIDE, now I get it...

thx,
ksstathead

Hi Ksstathead:

___The engineers and managers that were at the Press-Preview drive were are under very strict confidentiality so nothing exact was given out. Some of the individuals hinted that the 62 mph EV (I prefer to call it the glide capability ;)) will be standard fare in the 09 Prius-III. They would not even hint if the updated display will be available or not :( Everything else is just a few paraphrases of what was previously posted.

___I would suspect the EV button will make it given it is now on the new 08 HiHy. If they got that vehicle past the EPA, I see no reason why the PHEV version minus the P would not make it as driven?

___Having said all of that, the PHEV-6 makes the Prius-II a completely different animal in terms of what any of us could do with it. I believe the range is way too short for the everyday consumer and who would not want a 20 – 40 miles range but with a < $1.5K OEM upgrade, who here would not purchase this short range plug-in w/ the seriously upgraded capability today if it were available on the lot :D

___With Toyota’s recent announcement of up to 400 of these babies hitting American roads (for testing and acceptance purposes only ;)) I have a feeling Toyota wants that ECU and MFD programming to make it into the wild so as to make the American PHEV conversions worth so much more then they are today. We are talking about real world speed no fuel use PHEV’s when this thing gets out and that in and of itself is enough to say, “I am buying a Prius” for many!

___I should have done this in the first post but I want to personally thank Bill Reinert for making the Press-Drive possible for Blake and I. It is one thing to speak with the engineers and such but another to be speaking with a media person and turn around for a 5-minute conversation with one of my real-life heroes working deep inside of Toyota! He is just as funny and engaging as he is in film and was one of the many highlights we experienced at the NAIAS 2008 :D

___Good Luck

___Wayne

Wayne,

Any ideas on how I could "volunteer" to be one of the 400 testers? :p

What Skwyre7 said!

So these 09 Prii would be out this fall as an 09 model?

Hi Ksstathead:

___The release date was very sketchy and probably because the guys on the ground did not know? I thought for sure it would be an October 08 release as an 09 but according to the Autoshow Press event schedule, Watanabe (Toyota’s CEO) is supposed to do a major release in Jan. of 2009 and it may be the Prius-III? Why the delay if there is a delay? I have no idea. Some have said they have seen the Prius-III on a “special” factory tour in Japan with confidentially agreements signed and no cels or cameras in the room but that means little either. I hope the release is this fall myself given my parents want one in the worst way now :)

___Good Luck

___Wayne

I'd be thrilled to be one of the 400 testers, but I'd bet Toyota would prefer a more typical "end user". When Tom Brady is testing a new football, and the public begins to believe that the new football allows ANYONE to throw like Tom Brady, then it's best not to let Tom Brady test it. ;)

Not that I'm Tom Brady. That's Jerad. I'm more like Eli. :)