Nissan Engineering Team Visit Dec. 3rd: Recap

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abasile said:
I have repeatedly seen the SOC *decrease* during regenerative braking, immediately following a long mountain ascent. Driving up CA-330 on my way home, I climb almost 5000 feet in about 14 miles (see http://www.mynissanleaf.com/viewtopic.php?f=31&t=3512&start=60#p143277" onclick="window.open(this.href);return false;), then descend about 150 feet in elevation. Almost invariably, I have seen my SOC drop during regen braking on that small descent. Sometimes this even translates into losing a charge bar. After transitioning from continuously discharging the battery to charging, perhaps the car is able to refine/improve its estimate of OCV.

I have seen the same thing. At the beginning of the descent, SOC decreases. Further down, it increases again, and then keeps increasing.

My problems with long descents is that the Leafs off-pedal regen in eco-mode is not sufficient to keep the speed down to acceptable levels (iow at or below speed limits). Thus I have to keep feathering the brake which is really anoying compared to decending on cruise control.

Were there any discussion on putting max regen on pedal lift ? At least in one driving mode ? I would REALLY appreciate having it all there and none on the brake pedal.
 
jkirkebo said:
Were there any discussion on putting max regen on pedal lift ? At least in one driving mode ? I would REALLY appreciate having it all there and none on the brake pedal.
I don't believe there was specific discussion of that but there was a request for multiple driving modes, including a max regen mode. Perhaps you'd like it be how I hear Tesla Roadsters are? ;) IIRC, the regen's so strong that they intentionally have the brake lights come on when you lift off the accelerator.

Side notes: I was amazed by how many people raised their hands in in the room in response to some of the questions.

How many have PV at home? I'd say at least 1/3 to 1/2 the folks in the room raised their hands.
How many have Phil's EVSE upgrade? I'd guess somewhere between 1/2 to 3/4.
For how many is the Leaf their first pure EV? I'm guessing at least 3/4.
 
I was seated near the Chief Engineer and noticed he was so ready to answer Kim's questions about the true kWh amount in the battery pack at one point.

Alas! ... he didn't have a chance amidst the Nissan QC guy kept asking the same 'what do you not like about existing DTE' question in different form. I thought it was a huge opportunity lost that the meeting was hijacked by this issue. He stirred up all the unnecessary frustrations in all the bayleafers. I thought it was already conceded by Nissan that DTE is not up to speed. I wish the Chief engineer had taken the stage and not the Nissan QC guy...

Thank you to Howard, Kim, Phil, Waidy for all the hard work and organization of the event! Thoroughly enjoyed it!
 
TEG said:
Something else I took away - the LEAF is just the first product of a whole line of electric vehicles that will be coming out. So the NISSAN staff that was there are thinking above and way beyond just the LEAF itself.
This is so great to hear. Thanks for relating it.
 
Caracalover said:
TEG said:
Something else I took away - the LEAF is just the first product of a whole line of electric vehicles that will be coming out. So the NISSAN staff that was there are thinking above and way beyond just the LEAF itself.
This is so great to hear. Thanks for relating it.

One of the questions for the Discussion session was about the future EV products such as the Infiniti EV, but we never got that far.
 
jackal said:
I was seated near the Chief Engineer and noticed he was so ready to answer Kim's questions about the true kWh amount in the battery pack at one point.

I kept looking towards Kadota-san to see if you would respond, and I sensed he may want to make a comment. But he was too polite to speak up, and I was too wimpy to cut off the conversation going on.
 
TEG said:
The message was clearly delivered and received that some owners want an SOC meter.
I would characterize the response as "OK, we hear you, and we are working on improvements in this area."
(In other words, no specific commitments, but it is clear that they know it is an area where we want them to make it better.)
Regarding not having specific commitments, I didn't want to take up valuable floor time by attempting to speak for Nissan (esp. since I have no visibility into their resources and processes), but some of us have worked in very large companies before or had business models that involved dealing w/other companies w/their own motivations.

Part of the perceived lack of commitment on certain improvements (broader than just the SOC meter) is perhaps they didn't want to promise something they can't deliver or may not be able to deliver in a timely fashion. It's better to under promise and over deliver than the other way around. Car companies generally are working on the next project years in advance and they may not have the resources to devote to improving a car that will be change significantly/be at the end of its generation (whenever that is). They might've actually fixed some of the issues that were brought up or already have it in the pipeline...

I used to work on mobile devices and we had a problem where the manufacturers didn't have the much motivation to release updates for older devices (because it's integration, dev, test and support work), esp. ones that are no longer sold and thus no longer bring in revenue. This is most visible w/former Windows Mobile devices and can be seen w/Android devices, to some extent.

When I worked in another group, sometimes customers were reporting bugs that were known issues to us, but our hands were tied (due to policy) by saying that it was under investigation (even if I had finished testing the fix for it). The group had a lame policy of not acknowledging bugs. The other part was the sometimes the fix caused new/worse problems and would need to be pulled for the next update cycle. So, if we made a promise and didn't deliver when we said we would...

With the age of updates on certain consumer electronics (but not all), there seems to be some expectation of updates/improvements. There are certainly many counterexamples of devices receive few or no updates. (For instance, there was one firmware update for my now pretty old Samsung TV that IIRC, resolved some power up issues. Samsung hasn't released anything else the improved nor fixed anything. I'm sure they'd much rather sell me a new TV than expend resources on a TV that was discontinued a few years ago.)
 
whoa! I go away for a few hours and find 4 pages worth of posts on all that. Clearly we forum members are a passionate bunch. But I'm wondering if we should take that discussion to another thread?

I'm not sure if we mentioned it above (in the previous 8 pages) but Mark Perry did say that they want to meet with LEAF owners all over North America in a similar Town Hall format.
 
garygid said:
What DTE does a typical ICE require to be "mainstream"?
Because they have much longer range - not to speak of 5 minute refueling in every nook & corner of the country.

For widespread adoption of EVs, we need
- Better DTE or
- Much higher range at same price
 
evnow said:
garygid said:
What DTE does a typical ICE require to be "mainstream"?
Because they have much longer range - not to speak of 5 minute refueling in every nook & corner of the country.

For widespread adoption of EVs, we need
- Better DTE or
- Much higher range at same price

we covered this as well in a couple of bullets. I took a day (today) to decompress but tomorrow I'll combine the presentations into 1 or 2 Google docs and post the link. The example we gave was the Nissan Altima Hybrid, which refuels in about 7 minutes and goes 700 miles. You really don't need an accurate fuel gauge in this scenario.
 
I specifically asked Mark about Chademo vs. SAE L3. He said Nissan is staying with Chademo.

In a separate thread it looks like they will be adding inductive charging under the vehicle in 2014.
 
highcountryrider said:
Sorry, what is OCV in this context? :?:

open circuit voltage. The only time this used is when the car has been at rest for some time (length?). Once you start driving, The car does not know the OCV, but can make an approximation by counting amp hours consumed among other calculations to provide the current state of charge for the battery while in use. Once you turn the car off and let it rest, the computer can then get another reading of the OCV when you start your next trip.
 
palmermd said:
highcountryrider said:
Sorry, what is OCV in this context? :?:
open circuit voltage. The only time this used is when the car has been at rest for some time (length?). Once you start driving, The car does not know the OCV, but can make an approximation by counting amp hours consumed among other calculations to provide the current state of charge for the battery while in use. Once you turn the car off and let it rest, the computer can then get another reading of the OCV when you start your next trip.
Would this imply that if you've been driving for a (long) while and/or the battery is low and you want to get a more accurate estimate of DTE, that you might (pay attention to your driving speed for a few miles to smooth your average consumption, then pull over and) shut the car off and "reboot" it?

Would that be sufficient to get a good, new OCV (and thus DTE) reading, or does the car really does have to be "at rest for some time"...?
 
palmermd said:
highcountryrider said:
Sorry, what is OCV in this context? :?:

open circuit voltage. The only time this used is when the car has been at rest for some time (length?). Once you start driving, The car does not know the OCV, but can make an approximation by counting amp hours consumed among other calculations to provide the current state of charge for the battery while in use. Once you turn the car off and let it rest, the computer can then get another reading of the OCV when you start your next trip.
I find this particularly interesting in that I sometimes will come back out to the car after stopping somewhere briefly on the way home to discover that I suddenly have noticeably less charge remaining than I had when I parked it a half hour earlier. It is of course particularly noticeable when I stop with just a bar or two of charge left because I come back out and discover the remaining bars entirely gone and immediately get the out-of-charge warnings. I had wondered if turning the car off and on *caused* a loss of charge (to fill the brake backup power capacitor or something) -- and that perhaps it was safer to head straight home rather than trying to squeeze in another errand if my charge was getting low. Interesting to think that perhaps part of what I'm seeing is just a correction of the previously estimated state-of-charge.
 
Yes, I think they were suggesting that we don't put ultimate faith in "GIDs" as the system may periodically make "corrections" based on new measurements it is able to make, particularly when you are stopped.
 
i have noticed that the DTE does change after powering down and back up again, but usually the car has sat for a while between the power-off event and power-on event. in light of what Kadota-san said, this makes sense. as for how long the battery has to be at rest, i suppose we'd just have to experiment with power cycling the car over longer and longer periods to try to figure out at what point the computer starts trusting the OCV. of course this could be dependent on battery temperature so the length of the trip and the ambient temperature could have an effect on the interval.
 
Thanks. :)

So the Gid is computed OCV then, based on what has been withdrawn from the battery, load,
temperature, etc.?

palmermd said:
highcountryrider said:
Sorry, what is OCV in this context? :?:

open circuit voltage. The only time this used is when the car has been at rest for some time (length?). Once you start driving, The car does not know the OCV, but can make an approximation by counting amp hours consumed among other calculations to provide the current state of charge for the battery while in use. Once you turn the car off and let it rest, the computer can then get another reading of the OCV when you start your next trip.
 
edatoakrun said:
Any discussion of how Nissan can assist in US DC Charge infrastructure development?

They have helped by making less expensive hardware, and CHAdeMO chargers are finally getting their UL approvals.
*but* the costs to install and operate them is proving prohibitive for many attempts. Basically I was told that the USA situation is very frustrating since the power infrastructure is controlled by lots of little power companies each with their own ideas of how to bill and control hook up to "their" grid.

The point was made that Oregon & Washington have generally been more reasonable and roll-outs are underway there, but California is a bit of a mess right now.
 
TonyWilliams said:
EVDRIVER said:
Great meeting and a definitive no answer regarding an upgrade for a 6.6kw leaf charger on existing LEAFs. But we knew that:)
Oh, they had an answer... no. They mentioned all the wiring harness changes, etc.

I think I heard that the 6.6kW will actually be in the front of the vehicle, with the layout of the components under the front hood being somewhat redone for the next model refresh.

BAYLEAFs made the point that one of our primary interests in this dialog is to do what we can to help them sell more cars. In that regard, I think we don't really know what we are doing, so hopefully Nissan can "steer us" if they think there is some way we can help. So with that said, I am mindful of the concern that "talking up" a future model too much could hurt short term sales as we don't want to make someone go into "wait and see" mode.
So, for anyone on the fence, little future improvements might be accompanied by a price increase (but hopefully not), so waiting could be a mistake!

6.6kW will be a nice little improvement, but many people are doing just fine even with only 3.3kW
 
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