Meeting with Nissan, Phoenix, Jan 8, 2013, 6pm, drinks prior

[TonyWilliams]

... Tony's range chant...

Freud?

I do that, but only late at night.

 

[edatoakrun]

I wish you could have written that six months ago, Phil.

Am I wrong to suspect you wouldn't have said "...it's a combination of a small amount of degradation combined with instrumentation errors..." without LEAFSCAN results tending to support it?

Personally, and as an experienced EV Engineer, I agree with Nissan for choosing passive cooling. I do not think in the future we will see much active cooling for EV battery systems.

The chemistry will improve so as to be more heat tolerant, and the problems we have now will disappear!

If Nissan had installed active cooling, the Leaf would be heavier, have less range, and be significantly more costly. In addition, Active cooling requires power, which means it must be plugged in most of the time or even more drastic range reduction will occur.

Keep in mind, it's not actually proven there is much actual degradation! I believe it's a combination of a small amount of degradation combined with instrumentation errors (failures), and that once Nissan corrects the software in the LBC (Battery ECU), apparent "lost" capacity will return. Let's at least give them time to fix this before condemning them!

Just because a Leaf owner cannot drive as far, doesn't mean the battery has a fault. The LBC determines all charging and discharging limits, and if it's being "overprotective" like I suspect, once they correct this, range will magically return. If it doesn't, Nissan will fix it. Regardless, I'm convinced Andy was sincere and Nissan is going to make this right.

-Phil

 

[Stanton]

Personally, and as an experienced EV Engineer, I agree with Nissan for choosing passive cooling. I do not think in the future we will see much active cooling for EV battery systems.

Well said (as usual). Back in 2010, when I realized the Leaf would be the only "new generation" EV to have a passive cooling system, I decided to buy. The test drive tour may have sealed the deal, but that one design decision told me this was going to be the best "bang for the buck" EV I would be able to buy for the foreseeable future.

 

[LTLFTcomposite]

Wow these recent posts really open up a lot of questions in my mind. For one thing, I've always wondered if the solution to lost bars couldn't just be to update the SW to show more bars:

"Oh you're down to 8 bars? No problem, here, we fixed your car, you have 12 bars again! What's that? You say you can only go 15 miles from full SOC to turtle? You must be using the heat too much, or driving uphill both ways to and from work."

But "eating into" the reserve percentage is an angle I hadn't considered. So let's say you're at the four year mark with 50,000 miles, and you drop to 8 bars. Are you saying the software "fix" could be to reduce the reserve, so 100% SOC is stuffing more in, and turtle is wringing more out? Maybe that would restore the range, but aren't you on a death spiral at that point, pushing the aging battery to greater extremes? It gets you (and Nissan) through the next 13 months and 13,000 miles, but then the capacity warranty is up.

 

[Volusiano]

Personally, and as an experienced EV Engineer, I agree with Nissan for choosing passive cooling. I do not think in the future we will see much active cooling for EV battery systems.

The chemistry will improve so as to be more heat tolerant, and the problems we have now will disappear!

If Nissan had installed active cooling, the Leaf would be heavier, have less range, and be significantly more costly. In addition, Active cooling requires power, which means it must be plugged in most of the time or even more drastic range reduction will occur.

Keep in mind, it's not actually proven there is much actual degradation! I believe it's a combination of a small amount of degradation combined with instrumentation errors (failures), and that once Nissan corrects the software in the LBC (Battery ECU), apparent "lost" capacity will return. Let's at least give them time to fix this before condemning them!

Just because a Leaf owner cannot drive as far, doesn't mean the battery has a fault. The LBC determines all charging and discharging limits, and if it's being "overprotective" like I suspect, once they correct this, range will magically return. If it doesn't, Nissan will fix it. Regardless, I'm convinced Andy was sincere and Nissan is going to make this right.

-Phil

I agree with what you said here, Phil, from the technical perspective that the lack of TMS may not necessarily be a bad thing.

I assume when you said "Let's at least give them time to fix this before condemning them", you're talking about some kind of software solution to 1. Fix the instrumentation accuracy, and 2. Maybe loosen up "conservative" margins a bit to give back some more range that's been blocked off by being maybe a little too conservative.

That's all fine and dandy. I just want to clarify that the angle I'm coming from is not to criticize Nissan on the merit of their technical choice of whether to implement TMS or not. They are justified to consider the pros and cons on this and choose what they believe to be the best solution -> no TMS.

My real criticism is from the customer service angle. My criticism is about Nissan's choice to over-advertise (whether deliberately or not) and downplay the effect that heat may have on their battery capacity and not sufficiently warn AZ drivers up front at the point of sale about the caviat of buying their LEAF in hot climate. This is a very KEY factor that would affect someone's purchase decision of a LEAF in AZ.

So I want Nissan to have a special remedy for hot climate owners not because they chose not to have TMS, but because they chose to tell AZ owners that these buyers should have no worry about buying a LEAF in AZ because they have already extensively tested the LEAF in AZ and found no problem.

 

[DarkDave]

I'm not even talking about dipping into the reserve percentage here. When I charge my car to 80% and the gauge says I have 74 miles of range in ECO mode, that's a total lie. The calculations the software uses for determining remaining range have no basis in reality or even previous driving history to calculate an accurate miles/kWh value. That should most definitely be fixed. Andy's response suggested that it's not resolved in 2013 cars, and there would be more work required to resolve it.

 

[Ingineer]

I wish you could have written that six months ago, Phil.

Am I wrong to suspect you wouldn't have said "...it's a combination of a small amount of degradation combined with instrumentation errors..." without LEAFSCAN results tending to support it?

I think I did say essentially this many months ago in another thread!

Unfortunately I haven't been able to get LEAFSCAN™ on any Phoenix cars, so that's not any source of information for me. Clearly, if you just look at all the results and what people are actually seeing, there are a lot of discrepancies. Nissan has even somewhat hinted that there are instrumentation issues, which is what I originally suspected.

In any event, To confirm my theories, I'd have to actually do some lab tests on the battery pack, not just take LEAFSCAN™ readings, as they are only as good as the data the LBC reports. I think the LBC definitely needs some software changes, and I bet Nissan is working on this right now. Keep in mind it takes a while to do this kind of work, test it thoroughly, then get it out to the dealers and issue the service campaign. They've told us this spring. Sounds about right to me!

-Phil

 

[LEAFfan]

Personally, and as an experienced EV Engineer, I agree with Nissan for choosing passive cooling. I do not think in the future we will see much active cooling for EV battery systems.

The chemistry will improve so as to be more heat tolerant, and the problems we have now will disappear!


-Phil

I agree, active cooling always seemed like a bandaid to me.

But from the town hall meeting it seems that heat tolerant battery chemistries will not be available (at Nissan) in the near future

There will be a much different BC for the LEAF MY 2015.

 

[dgpcolorado]

There will be a much different BC for the LEAF MY 2015.

While I'd like to believe that because I want the LEAF to succeed, it remains to be seen whether or not Nissan will actually have a more heat resistant chemistry for MY 2015. I hope that you turn out to be correct.

Might not do those of us with older cars much good since a new chemistry would mean a new BMS, even if the format of the new cells was compatible with the current pack layout, and that might be impractical. Sure would be nice though.

 

[Volusiano]

I wish you could have written that six months ago, Phil.

Am I wrong to suspect you wouldn't have said "...it's a combination of a small amount of degradation combined with instrumentation errors..." without LEAFSCAN results tending to support it?

I think I did say essentially this many months ago in another thread!

Unfortunately I haven't been able to get LEAFSCAN™ on any Phoenix cars, so that's not any source of information for me. Clearly, if you just look at all the results and what people are actually seeing, there are a lot of discrepancies. Nissan has even somewhat hinted that there are instrumentation issues, which is what I originally suspected.

In any event, To confirm my theories, I'd have to actually do some lab tests on the battery pack, not just take LEAFSCAN™ readings, as they are only as good as the data the LBC reports. I think the LBC definitely needs some software changes, and I bet Nissan is working on this right now. Keep in mind it takes a while to do this kind of work, test it thoroughly, then get it out to the dealers and issue the service campaign. They've told us this spring. Sounds about right to me!

-Phil

Based on what's being discussed, it looks like we can break it down into 3 areas of capacity loss:

1. True capacity loss due to heat exposure.
2. Perceived capacity loss due to instrumentation error.
3. Upfront capacity loss (more like untapped built-in capacity) due to conservative margins set by Nissan.

While 2 and 3 can be fixed with better software by Nissan, 1 is real, permanent, and can't be fixed by Nissan using software. 1 is also not by a "small" amount, as evident by Tony's Phoenix range test showing that it's real and it's significant enough.

 

[Stanton]

Might not do those of us with older cars much good since a new chemistry would mean a new BMS, even if the format of the new cells was compatible with the current pack layout, and that might be impractical. Sure would be nice though.

I don't assume this to be true. In fact, I'm COUNTING on Nissan being able to adapt/modify the existing BMS to sell us "old timers" a new battery technology down the road!

 

[LEAFfan]

Yes, but I think Phil is saying that because of the high heat, it affected / damaged the BMS electronics and doesn't allow us to use all the capacity which would cause less range.

 

[Stoaty]

Keep in mind, it's not actually proven there is much actual degradation! I believe it's a combination of a small amount of degradation combined with instrumentation errors (failures), and that once Nissan corrects the software in the LBC (Battery ECU), apparent "lost" capacity will return. Let's at least give them time to fix this before condemning them!

That depends on what you consider "much", since Nissan's own testing of some of the Phoenix Leafs found remaining capacities of 85% and lower. For such a short period of time, and without proper disclosure up front by Nissan, I would say that is quite a bit. However, in all but the hottest areas you are probably correct.

 

[surfingslovak]

Keep in mind, it's not actually proven there is much actual degradation! I believe it's a combination of a small amount of degradation combined with instrumentation errors (failures), and that once Nissan corrects the software in the LBC (Battery ECU), apparent "lost" capacity will return. Let's at least give them time to fix this before condemning them!

That depends on what you consider "much", since Nissan's own testing of some of the Phoenix Leafs found remaining capacities of 85% and lower. For such a short period of time, and without proper disclosure up front by Nissan, I would say that is quite a bit. However, in all but the hottest areas you are probably correct.

Thank you, that's exactly the point I wanted to raise. Nissan performed a battery bench test in Casa Grande in July, and shared the results with affected owners. I wouldn't necessarily call 14 or 15% capacity loss in 1 1/2 years minimal, but that's a question of semantics. It would be good to keep things in perspective though. While a lot of attention has been given to capacity loss, local climate, and the inherent properties of the battery chemistry used in the LEAF, I believe that Nissan has not acknowledged how inadequate instrumentation can compound the problem and rob owners of even more range. Note that some of them reported a subjective loss of autonomy between 20% to 30%. That's significantly more than could be expected based on battery degradation alone. I think this is one of the reasons why owners might feel that a warranty based on capacity bars alone is not enough to remedy the situation.

As to the question of battery chemistry: I have to agree that a TMS could represent a large overhead in a vehicle like the LEAF. But you don't have to go far to see what other approaches could be considered. Look at Honda or even CODA, and their chemistry and design choices. I think these are valid reference points, since both manufacturers were aiming at the same market segment.

While it can be educational and perhaps even entertaining, I don't think that Nissan wants us to help re-engineer their battery. As consumers, we should be able to rely on the manufacturer, its expertise, its testing, and ultimately, performance projections. In this context, a capacity warranty is a step in the right direction. While the implementation details are certainly debatable, the consumer should not need to worry about the battery, if Nissan is underwriting its performance.

Based on anecdotal data from owners in different locales, I think it's well-accepted now that the LEAF performs great in Seattle, and it appears to be doing significantly worse in Phoenix. Regardless of the underlying reasons, I have to agree with Volusiano's earlier comment that the relative difference in performance was not clearly communicated at the time of purchase. Yes, there were some references in the owner's manual, but I believe that they were simply too vague to allow the majority of prospective owners to come to the right conclusions. I certainly did not know enough to say how much range loss I should see in my location after a year and half.

Based on owner sentiment, I think it's also safe to say that the level of customer service extended by local dealers and by Nissan North America was not satisfactory in many cases.

 

[Ingineer]

Based on what's being discussed, it looks like we can break it down into 3 areas of capacity loss:

1. True capacity loss due to heat exposure.
2. Perceived capacity loss due to instrumentation error.
3. Upfront capacity loss (more like untapped built-in capacity) due to conservative margins set by Nissan.

While 2 and 3 can be fixed with better software by Nissan, 1 is real, permanent, and can't be fixed by Nissan using software. 1 is also not by a "small" amount, as evident by Tony's Phoenix range test showing that it's real and it's significant enough.

A range test is NOT conclusive, since range depends on the LBC (battery ECU) allowing a full normal charge, and then allowing a full normal discharge. It may very well not being allowing full access to the "ends", which I have seen supporting evidence for. For instance if it erroneously "thinks" the battery is somehow degraded, it may limit charging/discharging, or both resulting in artificially reduced range.

Again, (I keep saying this) I don't truly know what's going on, but I've definitely seen enough weird numbers to be convinced there's a good possibility that there is some problem with the LBC not allowing access to the whole capacity. This may well be due to SOME real degradation, but it may also be "over-reacting" and restricting a lot of still real usable capacity because of these errors.

-Phil

 

[EdmondLeaf]

Again, (I keep saying this) I don't truly know what's going on, but I've definitely seen enough weird numbers to be convinced there's a good possibility that there is some problem with the LBC not allowing access to the whole capacity. This may well be due to SOME real degradation, but it may also be "over-reacting" and restricting a lot of still real usable capacity because of these errors.

-Phil

So I think is fair to say, that it can be one way or the other

 

[surfingslovak]

If the LBC, related software or instrumentation can have such a profound effect on the autonomy, wouldn't this give more credence to calls for a true range warranty? You see, from an owner perspective, it matters little, if it's battery degradation or perhaps some other defect, that's restricting the range of the vehicle. I believe Tony made that point earlier last year, and this was one of the motivations for the range test on September 15.

 

[palmermd]

If the LBC, related software or instrumentation can have such a profound effect on the autonomy, wouldn't this give more credence to calls for a true range warranty? From an owner perspective, it does not really matter, if it's battery degradation or perhaps some other defect, which is restricting the range of the vehicle.

+1. My thoughts exactly.

 

[Ingineer]

If the LBC, related software or instrumentation can have such a profound effect on the autonomy, wouldn't this give more credence to calls for a true range warranty? You see, from an owner perspective, it matters little, if it's battery degradation or perhaps some other defect, that's restricting the range of the vehicle. I believe Tony made that point earlier last year, and this was one of the motivations for the range test on September 15.

I would agree, except this is hard to test for because of the time involved and the wide variance. You'd pretty much need to transport the car to a specific test track (or duplicate them all over the country) and drive it with a fixed profile. Really hard to quantify!

I believe the LBC can be fixed to work properly, and since it records all energy in/out, as well as knowing the health of each cell block, it will be able to accurately calculate any degradation. Right now there are clearly some issues Nissan must fix. Hopefully this will also give us a more accurate SoC, and thus the GoM will even benefit.

-Phil

 

[downeykp]

Would Leafscan help with this?