Nissan Engineering Team Visit Dec. 3rd: Recap

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gascant said:
...they have stepped up their efforts on the home interface unit for the LEAF, (vehicle to home, or V2H) and are deploying it there. We lobbied to get them to set some up in members homes over here as well...

If there was any one thing that I would think of as almost an "announcement" was the suggestion that they are very serious about deploying that soon. Prior to the meeting, I just thought of it as another "me too" research project that might not go anywhere anytime soon. V2G / V2H is one of those things stuck in a long R&D cycle with standards needing to get worked out, and a huge uphill with the utilities to actually get them to customers. Hopefully Nissan is able to push this technology forward, but I don't want to see them spread themselves too thin. (For instance, hopefully pushing V2H doesn't slow down the CHAdeMO rollout effort.)
 
garygid said:
I suggest that PERHAPS the GID/2 (0 to 140.5) is an estimate of the remaining USABLE pack voltage (about 394v full and 254v "exhausted").
I will have to do some graphing of some logs to see if that scaling and "meaning" works.

However, I believe that the TRUE low limit for the Pack really should be based upon the voltage of the lowest cell-pair, NOT on the Pack Voltage (to avoid damage to that lowest cell-pair).

Yes, the chief engineer did mention that they measure 96 voltages, and that the lowest / highest was part of the equation, as we know it has to be.

Much of this conversation, as previously posted, then centered around how many variables that they monitored to come up with DTE. To that end, Nissan IT folks were working on including elevation with the mapping and navigation equation. I think they are working toward the only possible solution that is possible to determine the most pertinent variables to calculate range.
 
linkim said:
Also, one of our local LEAF owners generously provided the Nissan Japan visitors a gift from California that will require them to check their luggage at the airport (assuming it is not gone before they leave).

That was me Kim.

Judging from what the younger engineers said, I don't think it was going to make it through the night without being consumed. I gave them 8 bottles of wine. In my dealings with Japanese folks (in my first job), it is very important to exchange gifts. Notice that they gave us all LEAF hot wheels.

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TonyWilliams said:
garygid said:
I suggest that PERHAPS the GID/2 (0 to 140.5) is an estimate of the remaining USABLE pack voltage (about 394v full and 254v "exhausted").
I will have to do some graphing of some logs to see if that scaling and "meaning" works.

However, I believe that the TRUE low limit for the Pack really should be based upon the voltage of the lowest cell-pair, NOT on the Pack Voltage (to avoid damage to that lowest cell-pair).

Yes, the chief engineer did mention that they measure 96 voltages, and that the lowest / highest was part of the equation, as we know it has to be.

Much of this conversation, as previously posted, then centered around how many variables that they monitored to come up with DTE. To that end, Nissan IT folks were working on including elevation with the mapping and navigation equation. I think they are working toward the only possible solution that is possible to determine the most pertinent variables to calculate range.

Here is a crack at the complexity of challenges the Nissan algorithm programmers have to rise to.
Here are my notes on the Leaf SOC as presented, plaease excuse my lose interpetation of the information.
Seems more like a dark art than math based on quantifiable scientific information.
Waring read at your own risk of being even more confused when you get to the last part.

Basic process of Nissan on how they estimate SOC.
Load on the Lithium Battery pack Voltgae V & Current i
At start up can measure Open Circuit Voltage (OCV)
Graph OCV over driving distance along with varying current and voltage estimate using V and i convet to SOC
Difficult to estimate during charging/discharging. Cannot measure OCV with load. Estimate OCV from V and i during driving time line.
End of driving again difficult to estimate. Just after charging/discharging. cannot measure OCV with influence of chemical reaction in battery.
Adjustment of estimate SOC value is adjusted to match vehicle behavior "Mysterious moves" occures in some scene.
Full charging stops at MAX SOC 192 Cells.
Decend Cell of max tolerance. Estimate value (Si) cells Real Value
Decending Cell of average estimated value (2*) Correction of estimate tolerances cause by sensore, cell tolerance etc.
Decending Cell of minimum tolerance.
(1) Shift SOC by area e.g. drop at shift timing
Estimate e.g.(2*) this decends but then assends briefly then desends back down to empty.
Empty___________________________Judge empty at Min SOC.
Here I give extremly brief notes about the 12 segment SOC meter.
SOC sharp drop cannot be recognized between the 6th & 4th segments (example shows). Basically a series of calculated corrections are done so in summary to prevent an overestimate SOC.
Increase risk of empty. SOC becomes "0" (I believe its below the segment) with some energy.
This is to Reduce risk of empty.
Estimated Distance to Empty (DTE)
Energy consumption ratio could be more varible factor than SOC.
DTE would be better indicator - carefule drivers
DTE(km)=SOC(KWH) x Energy consumption rate (km/KWH)
Changed by Acceleration, Regen, Climae Ctrl, Gradient etc.

If it sounds confusing that's because it is, we do not have the complete picture.
Danny
 
DannyAmes said:
Here is a crack at the complexity of challenges the Nissan algorithm programmers have to rise to. ...

Interesting. It's easy to fall into thinking of the battery as some idealized "energy balloon" that simply inflates and deflates, rather than what it really is -- dozens of cans of highly reactive chemicals that do what we want only to a certain degree, and then only within certain parameters.

It's good to appreciate the strides in the state of the art that have made a car like LEAF possible. And good to know that there's still significant room for improvement. While a lot of this has been driven by portable electronics market in the last 20 years, there is nothing on earth to compare to the automotive market in driving practical improvements. Now that EVs are becoming part of that stream, the next decade is going to be very interesting.
 
JohnOver said:
That was me Kim.

Judging from what the younger engineers said, I don't think it was going to make it through the night without being consumed. I gave them 8 bottles of wine. In my dealings with Japanese folks (in my first job), it is very important to exchange gifts. Notice that they gave us all LEAF hot wheels.

Thanks JohnOver for your generous contribution to the meeting with the 8 bottles of wine for our Japanese visitors. We had several discussions over what to give to the Japanese. I think the wine is an excellent choice - a truly California product, and produced by a LEAF owner. We intentionally played down the presentation of the wine (sorry JohnOver) at the end of the meeting because the Nissan visitors from the US/UK did not receive any gift from us.

The gifts may not make it to Japan, but the spirit will.

Thanks JohnOver
 
oakwcj said:
...The Chief Vehicle Engineer called it a great first birthday party for the LEAF...

On the same day, LEAF was also getting flowers and honors at the Tokyo motor show:


Chief Operating Officer Toshiyuki Shiga, Nissan Car of the Year trophy...
 
For those who are following this thread but haven't yet seen the "Towable Turbine Powered [30KW] CHAdeMO Charger" threads, check this out:
http://www.mynissanleaf.com/viewtopic.php?f=37&t=7104" onclick="window.open(this.href);return false;

Excellent picture of Hidetoshi Kadota, Nissan's Chief Vehicle Engineer for the Leaf, and Phil (Ingineer):
http://www.mynissanleaf.com/viewtopic.php?p=155957#p155957" onclick="window.open(this.href);return false;

Another related thread (with posts from Phil) is here ("The “range–extended” EV considered"):
http://www.mynissanleaf.com/viewtopic.php?p=155656#p155656" onclick="window.open(this.href);return false;
 
TEG said:
gascant said:
...they have stepped up their efforts on the home interface unit for the LEAF, (vehicle to home, or V2H) and are deploying it there. We lobbied to get them to set some up in members homes over here as well...

If there was any one thing that I would think of as almost an "announcement" was the suggestion that they are very serious about deploying that soon. Prior to the meeting, I just thought of it as another "me too" research project that might not go anywhere anytime soon. V2G / V2H is one of those things stuck in a long R&D cycle with standards needing to get worked out, and a huge uphill with the utilities to actually get them to customers. Hopefully Nissan is able to push this technology forward, but I don't want to see them spread themselves too thin. (For instance, hopefully pushing V2H doesn't slow down the CHAdeMO rollout effort.)
My house was without power for several days recently, and my Leaf had plenty of charge. I sure do wish I could have used it to have some lights. I drove it every day anyway, as Burbank just opened some L2 chargers and I was headed there anyway. I assume that is what you mean by V2H. Really would have made me the envy of the neighborhood if that was an option.
 
I've put together the presentations we delivered on Saturday into a single PDF file. I'll post a link to that as soon as I get all the contributors' permissions to do so (or will edit them out if preferred). In the meantime, here is an Appendix that we gave them showing typical LEAF mods. Many thanks to linkim for putting it together.
SEE BELOW FOR LINKS TO BOTH FILES
 
Given that some did not want their names or presentations posted, I have sanitized both files and posted them where they can be downloaded as PDF files. Here is the link to the main presentations:
http://www.mediafire.com/?g3mzpshd2pfuulm" onclick="window.open(this.href);return false;

And here is the link to the appendix containing the LEAF owner modifications:
http://www.mediafire.com/?3dsou4uiyc5bmu8" onclick="window.open(this.href);return false;
 
Something else that occurred to me...

Kadota-san talked of the wind splitting headlight design we all find so...umm... "charming"...
He said something like "it is a new design for EVs". And we may see it on other EVs.
Perhaps the Infiniti EV, or some other Nissan models will come with those "bug-eye" lights.
 
gasmiser1 said:
Howard-

Very helpful to have the slides to share with people that couldn't make the meeting.

Thanks
In looking over the published slides, keep in mind that not everything was covered (some was skipped), partly due to lack of time and due to other more important discussions. Also, not everything was covered in equal depth. I didn't even know about the questions on page 49.

I don't believe any of the appendix was covered but Nissan should have all the slides/materials.

LOL re: the "charming" lights! I remember something else came up that was "charming", but I forget what.
 
cwerdna said:
LOL re: the "charming" lights! I remember something else came up that was "charming", but I forget what.
The horn. The presenter characterized it, initially, as polite, but either Kadota-san or someone in the audience said it was charming.
 
gascant said:
cwerdna said:
LOL re: the "charming" lights! I remember something else came up that was "charming", but I forget what.
The horn. The presenter characterized it, initially, as polite, but either Kadota-san or someone in the audience said it was charming.
Guilty. :D
 
gascant said:
Given that some did not want their names or presentations posted, I have sanitized both files and posted them where they can be downloaded as PDF files. Here is the link to the main presentations:
http://www.mediafire.com/?g3mzpshd2pfuulm" onclick="window.open(this.href);return false;

And here is the link to the appendix containing the LEAF owner modifications:
http://www.mediafire.com/?3dsou4uiyc5bmu8" onclick="window.open(this.href);return false;

If some mods/upgrades were not found in the appendix, my apologies. You guys are too creative to keep up so I may have overlooked your good work. I was trying to coordinate my powerpoint information with that of gascant's so sometimes things may have fallen through the cracks. In the end, gascant came through and put everything together.

Kudos to gascant.
 
I was very impressed with the organization of the meeting. All my key questions were given plenty of exposure during the presentation. Thanks to gascant and all the others.

oakwcj said:
The most impressive visual in the CVE's presentation showed the LEAF driving on water. Or, more precisely, through a road flooded by 750 mm [30"] of water. It was astonishing to see the water level rise above the top of the charging port while the car plowed blithely through the waves, seemingly unaffected by the deluge.
Small correction: my notes say the water depth was 700mm (27.6") not 750mm. Still very impressive, and graphics showed how the water line was above the battery and other drive electrical components.

Kadota-san also showed a dramatic artificial lightning bolt test onto the roof of the Leaf with no apparent damage, and several severe simulated crash tests with an impact ram. I believe the simulated speed was 80 km/hr. He stated that these crash tests did not compromise the integrity of the battery case. Impressive considering the recent news about the Volt fires following crash tests.

He presented graphics showing how the battery's placement near the Leaf's center of mass reduced the moment of inertia about a vertical axis, and thereby improved its handling on curves.

The Nissan team included 2 persons from Europe. In addition to Mark Perry, the US contingent included a QC fellow and several IT folks. Perry, who had a good sense of humor, admitting he liked to talk, came across as very knowledgeable about the technology as well as the market. In a private conversation with me he stated that his frequently-quoted statement that
"Car Wings data from the Leaf shows that there is no market need for more range or a faster charger"
was taken out of context. The added context was at the given price point. My understanding is that he meant that the technology they delivered for $34K was sufficient to find a market.

I asked Perry about whether we could possibly see future improved battery modules backward compatible with the 2011 and 2012 Leafs. He did not rule out that possibility as forcefully as he ruled out the 6.6kw charger upgrade, but he was not real hopeful. I asked about the recently-announced Argonne National Labs battery license, which promised an 80% improvement in capacity of Li-Mn batteries. He said the current Nissan battery is already better than the Argonne battery.

The last 20 minutes of the meeting were the most dramatic. There had been a very thorough discussion of the value of the SOC meter, the need for that to be standard, and the serious shortcomings of the present DTE (Guessometer). The American QC guy got up and said he understood what we wanted but he didn't understand why we wanted it. That almost caused an uproar.

Here is my answer to his question.
gascant had told me that only about half a dozen BayLeafers had Gary's SOC meter. I wish there had been time for me to get up and say the following:
Q1: Raise your hand if you have ever driven at least 75 miles on one charge.
Q2: Raise your hand if you have even driven a route with at least 1K ft altitude change.
Q3: Raise your hand if you have ever used public charging to extend your range, and wished to minimize the time you spent for that charging.

All those who raised their hand at least once would find the SOC meter very helpful in getting longer range and minimum in-route charging, with much less range anxiety. We should have offered to send a SOC meter to one of the Nissan engineers who drove a Leaf. More BayLeafers should order Gary's meter in kit form, or build their own. More to come about SOC and DTE.

Below I show a few pictures of the Google venue. I refrained from taking pictures in the meeting in order to adhere to the "no recording" direction.
IMG9711-S.jpg


IMG9721-M.jpg


IMG9724-S.jpg


IMG9726-S.jpg


Here is another picture of Phil's next project (one-off so far). The generator is an aircraft APU. While he show a Chademo connector, he has not yet used it. He has charged the Leaf battery at 5 KW using this generator and the charger electronics with a direct connection to the Leaf's battery. Do NOT try this at home.

IMG9712-M.jpg


The Google bowling alley

IMG9729-S.jpg


Finally, some nice visitors flew over.

IMG9722-L.jpg
 
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