Possible Widespread 2018-19 Traction Battery Quick Charge Problems

[DaveinOlyWA]

Yeah, I don't see this either. I also don't see how the battery will retain heat any differently than the current battery if the thermal resistance and capacitance are the same. Truthfully, given the greater capacity, the new battery should perform better from a heat generation standpoint given equivalent loads.

The 24kwh battery only accepts the full charge rate (~45kw I think?) for a limited time (until 80%?), after that tapering begins.

The 30kwh battery (and likewise the 40kwh) can accept the full charge rate for a longer period of time. So the loads (and power delivery) are NOT equivalent.

Do you have data to support this? I have several charge curves showing the knee at 35-45%. Nothing remotely close to what you are saying. In fact, I spent over an hour looking for a curve that did not start until after 50% and could not find one...

Let me add that you can charge at whatever to whatever for however long but the only thing I see as important is how much charge you got.

On average, only using 2nd, 3rd and 4th QC data on my 2018, my 2011 and 2013 got more charge in 30 mins less than half the time...

You might be mistaking the 30 kwh pack which had a MUCH steeper charge profile and I would see the knee at 74 to 83 %.

 

[Oils4AsphaultOnly]

The 24kwh battery only accepts the full charge rate (~45kw I think?) for a limited time (until 80%?), after that tapering begins.

The 30kwh battery (and likewise the 40kwh) can accept the full charge rate for a longer period of time. So the loads (and power delivery) are NOT equivalent.

Do you have data to support this? I have several charge curves showing the knee at 35-45%. Nothing remotely close to what you are saying. In fact, I spent over an hour looking for a curve that did not start until after 50% and could not find one...

Let me add that you can charge at whatever to whatever for however long but the only thing I see as important is how much charge you got.

On average, only using 2nd, 3rd and 4th QC data on my 2018, my 2011 and 2013 got more charge in 30 mins less than half the time...

You might be mistaking the 30 kwh pack which had a MUCH steeper charge profile and I would see the knee at 74 to 83 %.

Anecdotal. I probably have the details wrong, but the gist of it remains. The 24kwh starts throttling sooner (time-wise) than the 30kwh. My last collection (of admittedly bad data) showed peak current draw of 106A's from 11% all the way until 86%.

written another way. With the same internal resistance, If you start charging a 24kwh and 30kwh battery at the same time, at the same point (~25% SOC), the 30kwh will continue receiving the full charging power for a longer period of time - and thus receive more heat. You don't need math and detailed data to conclude this do you?

Edit: Upon re-reading your reply, I think I addressed the wrong question. So let me say that, "yes", my 30kwh battery receives more charge in 30 minutes than my 2013 did (sample size of only 3 though). I never QC'd for less than 20 minutes so I don't know if that still holds for the shorter-durations.

 

[DaveinOlyWA]

The 24kwh battery only accepts the full charge rate (~45kw I think?) for a limited time (until 80%?), after that tapering begins.

The 30kwh battery (and likewise the 40kwh) can accept the full charge rate for a longer period of time. So the loads (and power delivery) are NOT equivalent.

Do you have data to support this? I have several charge curves showing the knee at 35-45%. Nothing remotely close to what you are saying. In fact, I spent over an hour looking for a curve that did not start until after 50% and could not find one...

Let me add that you can charge at whatever to whatever for however long but the only thing I see as important is how much charge you got.

On average, only using 2nd, 3rd and 4th QC data on my 2018, my 2011 and 2013 got more charge in 30 mins less than half the time...

You might be mistaking the 30 kwh pack which had a MUCH steeper charge profile and I would see the knee at 74 to 83 %.

Anecdotal. I probably have the details wrong, but the gist of it remains. The 24kwh starts throttling sooner (time-wise) than the 30kwh. My last collection (of admittedly bad data) showed peak current draw of 106A's from 11% all the way until 86%.

written another way. With the same internal resistance, If you start charging a 24kwh and 30kwh battery at the same time, at the same point (~25% SOC), the 30kwh will continue receiving the full charging power for a longer period of time - and thus receive more heat. You don't need math and detailed data to conclude this do you?

Edit: Upon re-reading your reply, I think I addressed the wrong question. So let me say that, "yes", my 30kwh battery receives more charge in 30 minutes than my 2013 did (sample size of only 3 though). I never QC'd for less than 20 minutes so I don't know if that still holds for the shorter-durations.

Yeah, MUCH sooner. The 2018 starts its knee between 58 to 64% and seems to be somewhat "cold pack affected". This I am not sure about because I have yet to see any confirming data other than a few instances the knee started early in absence of high temps. So in a nutshell;

24 kwh Pack; QC charge profile MUCH too conservative.

30 kwh Pack; Just right! (for me as I did over 275 QCs in nearly 30,000 miles with minimal range loss) but there was a HUGE outcry on fast degrading packs. Nissan seems to have assumed (incorrectly) that heat was the culprit. It doesn't help but that is not the main cause so...

40 kwh Pack; Back to TOO conservative although not at the ridiculously low rate of the 24 kwh pack. Summer is coming and I can already hears echos of the screams coming over the horizon.

 

[Joe6pack]

We're really beating this to death and only time will tell. I don't expect much of a difference in thermal behavior between the various sizes. Heck, if nothing else, quick charging will become even more unnecessary with the larger pack.

 

[kennethbokor]

We're really beating this to death and only time will tell. I don't expect much of a difference in thermal behavior between the various sizes. Heck, if nothing else, quick charging will become even more unnecessary with the larger pack.

Agreed, this really is a non-issue.

 

[lorenfb]

It's starting to look very much like Nissan already knows that the 40kwh packs have the same design and/or build flaw as the 30kwh units. It is puzzling, though, that the QC speed restriction occurs regardless of pack temperature...

Have some forgotten the early posts, i.e. as the above?

 

[Evoforce]

We're really beating this to death and only time will tell. I don't expect much of a difference in thermal behavior between the various sizes. Heck, if nothing else, quick charging will become even more unnecessary with the larger pack.

Agreed, this really is a non-issue.

It is an issue for people who are interested in buying the vehicle or who have already purchased. Especially if these issues affect whether it meets their needs or if it may not meet their needs or expectations. For a lot of people, I would take a guess that it may not meet their needs or expectations. This forum has never been shy at rooting out the good, the bad, and the ugly.

 

[SageBrush]

It's starting to look very much like Nissan already knows that the 40kwh packs have the same design and/or build flaw as the 30kwh units. It is puzzling, though, that the QC speed restriction occurs regardless of pack temperature...

Social engineering ? As in, get the person off the QC before the pack heats up. Since heat appears to dissipate slowly in these packs the strategy makes sense.

 

[EVDRIVER]

We're really beating this to death and only time will tell. I don't expect much of a difference in thermal behavior between the various sizes. Heck, if nothing else, quick charging will become even more unnecessary with the larger pack.

Agreed, this really is a non-issue.

It is an issue for people who are interested in buying the vehicle or who have already purchased. Especially if these issues affect whether it meets their needs or if it may not meet their needs or expectations. For a lot of people, I would take a guess that it may not meet their needs or expectations. This forum has never been shy at rooting out the good, the bad, and the ugly.

This is true. Nissan misleads stated QC times as they do not show the high and low ranges. I see a generic statement that is wrong on their website, they really need a new advertising firm to do their content. The site disclosure is deceiving in context but also incorrect regardless:

30 MINUTES = 90 MILES*

*Approximate time, with available 240-V home charging dock (sold separately). LOL!

Below that is says 30 min/90 miles and 80% in 40min with NO disclaimers. I find that pretty deceptive since there is no disclaimer at all. Is there a disclaimer with fine print when you buy the car? I can see the average buyer being pretty upset when they try to get these numbers or do multiple QC sessions. I would not expect a detailed range but some kind of generic disclaimer. Nothing new here with Nissan hiding such details and over promising. I don't think this has ever changed since the first LEAF but at least they need to get their own vague facts correct at least. The biggest issue I see for consumers is the multiple QC misconceptions that will likely be pushed by sales people. "You can drive 150 miles and in 30 min go another 120 miles again, etc. Aside for SOC issues that limit all EVS the lack of cooling further complicates here were it may be of no or little impact on other cars. I do find 30 min to 80% at home on 240V impressive though


https://www.nissanusa.com/vehicles/electric-cars/leaf/range-charging.html

 

[kennethbokor]

Agreed, this really is a non-issue.

It is an issue for people who are interested in buying the vehicle or who have already purchased. Especially if these issues affect whether it meets their needs or if it may not meet their needs or expectations. For a lot of people, I would take a guess that it may not meet their needs or expectations. This forum has never been shy at rooting out the good, the bad, and the ugly.

This is true. Nissan misleads stated QC times as they do not show the high and low ranges. I see a generic statement that is wrong on their website, they really need a new advertising firm to do their content. The site disclosure is deceiving in context but also incorrect regardless:

30 MINUTES = 90 MILES*

*Approximate time, with available 240-V home charging dock (sold separately). LOL!

Below that is says 30 min/90 miles and 80% in 40min with NO disclaimers. I find that pretty deceptive since there is no disclaimer at all. Is there a disclaimer with fine print when you buy the car? I can see the average buyer being pretty upset when they try to get these numbers or do multiple QC sessions. I would not expect a detailed range but some kind of generic disclaimer. Nothing new here with Nissan hiding such details and over promising. I don't think this has ever changed since the first LEAF but at least they need to get their own vague facts correct at least. The biggest issue I see for consumers is the multiple QC misconceptions that will likely be pushed by sales people. "You can drive 150 miles and in 30 min go another 120 miles again, etc. Aside for SOC issues that limit all EVS the lack of cooling further complicates here were it may be of no or little impact on other cars. I do find 30 min to 80% at home on 240V impressive though


https://www.nissanusa.com/vehicles/electric-cars/leaf/range-charging.html

Yes true about the advertising. I did mention this to Nissan folks that they do need better clarity when it comes to setting long-distance use expectations. The Leaf can do 1-2 DCFCing within advertised times, but after that the throttling will kick in for successive charges. This feature is outlined in the Users Manual, but it is in legal-eze wording and may be missed by owners. Of course 99.9% of prospective buyers won't read the owners manual before purchasing.

The sales folks should mention this feature during pre-sales engagements as it is a purposefully built-in battery protection measure. However unfortunately this probably won't happen in many dealer visits. I spoke with a local dealer rep a couple of weeks ago about his and they had not heard about this at all. For the majority of use cases, this should not be a problem. But being properly informed, is something that should be done up front for good decision making. It is a shame-on-Nissan for not advising prospective buyers up front and hopefully this will change.

 

[Joe6pack]

I'll disagree. This throttling issue is an edge case. The typical LEAF user will never encounter it in any meaningful or material way. It sure does make for some good LEAF-bashing, though .

 

[DaveinOlyWA]

I'll disagree. This throttling issue is an edge case. The typical LEAF user will never encounter it in any meaningful or material way. It sure does make for some good LEAF-bashing, though .

Edge case? I am predicting the "edge" to be of phenomenal size and girth.

Have you heard of Jennifer? A LEAFer in AZ? Temps in the mid 90's? (Its barely Spring after all...) Lets take a map of the US and remove all the areas that don't see temps that warm. Whats left?

 

[Joe6pack]

Yes, edge case. I don't give a damn about a solitary person named Jennifer in Arizona. The typical LEAF is charged once per day overnight. Multiple quick charges in succession are an edge case.

 

[EVDRIVER]

I'll disagree. This throttling issue is an edge case. The typical LEAF user will never encounter it in any meaningful or material way. It sure does make for some good LEAF-bashing, though .

It's not an edge case that implies to very few people or circumstances, it's an inherent issue with the pack design which gets worse as the pack size grows. Do you have specifics on what a typical users habits are on the new 2018 LEAF? Can you share that data? I have spoken to many prospective buyers and owners that think the new LEAF can now be used for long road trips because of the larger pack to get from QC to QC, that is my sampling of "typical users" or all users I have encountered. It's not complicated, they lack of cooling makes this issue worse with a larger pack and it if is not resolved the typical user may end up having to be people that are forced to confirm to that model. We know why Nissan did this, they are stuck with their initial bad decision on no cooling and milking the NRE costs as best they can. These facts have been around a long time in the industry so no surprise as it is what it is. Ironically industry experts warned Nissan that this pack design would have all of these issues long before production started in 2011. It may surprise you how many poor EV decisions were made back then, even key decision makers at the top exec level of European auto makers were making pack decisions and overall EV product strategy and at that very time NONE of them had ever driven or rode in an EV! Nissan still has one foot in Japan with the LEAF but before it was two firmly planted, this is why you saw many Japanese market/climate centric influences on the LEAF. Design is a trade off and there are risk rewards in every decision.

 

[LeftieBiker]

There is a problem with trolls, all right, although I think that finding out who they are might surprise them. It's probably time to update our user filters.

 

[Joe6pack]

Sorry. I don't actually know if this forum has such a feature. I thought that's what he meant by filter.

Yeah, I guess I am fed up with the endless negativity and rampant speculation surrounding this car. Maybe that comes across as hostile. It's probably time for everyone to take a deep breath - me included.

I said I didn't post often. Now I remember why.

 

[arnis]

Old Leaf had a range of less than 100 miles.
Old Tesla had a range of 300 miles.
Both vehicles have pretty much the same daily mileage.
New Leaf has 150 miles of range. But daily commute is still the same.
Therefore, the greater the range, the less is battery used (percent-wize).
12-14 thousand miles per year. Therefore 35 miles per day as "very" average number.
No matter, 24kWh Leaf, 30kWh Leaf, 40kWh Leaf, 57kWh Bolt, 102kWh Tesla.

We are talking about average. Keep that in mind.

I'm heavy 24kWh Leaf user (more than 1.5x US average per year). I use QC like twice a month.
And I have QC stations everywhere. Like 30 within half an hour drive from my home.
If I had 40kWh Leaf, I think I'd rapid charge once a quarter.

 

[EVDRIVER]

I am not going to argue with a pedantic Internet troll whose primary purpose is to sow fear and doubt. The fact is you're wrong.

Fear and doubt? How about facts. Go read my other post to you in another thread, I'm not sowing fear or doubt just stating facts that anyone can validate and others understand. I don't care who makes the EV, without proper cooling you can't repeatedly QC a pack and the more that pack is stacked the less that heat will dissipate. Just because you may not need to QC multiple times or you think that is fringe or not for the average user does not change the actual facts. There are many people in market for an EV that don't understand this and would be very unhappy to know this limitation because it impacts their needs. Again, I have been a LEAF proponent since 2011 but I'm not going to act like a fanboy and defend packs that degrade fast or QC limitations. Just like Tesla made stupid mistakes with parasitic loads on pre 2015 cars I would call them out on it, at least they admitted and fixed it. The LEAF is not well designed for multiple QC events period, if you think that's not true then ask Nissan why they admit and state that. There is no new news here it's part of the original design and no surprise and has been an issue at a lower level for a long time, this is a function of design clearly as you can't heat a large sealed brick and expect it to cool quickly.

I would not call this a new issue but more something many people are not aware of on a comparative basis from EV to EV. For my needs and others this won't work even with a very good QC network because I don't have the desire to wait long times because of throttles charge rates. The larger pack allows longer travel distances which opens the perception of long distance travel but the reality is there are penalties that may not be present on other cars or experienced during shorter trips. Good luck driving long distance in hot weather up any substantial or even moderate grades without long charge times that are likely not anticipated. All this will go away when they cool the pack and everyone will see HUGE disparity in the cars, if they don't cool the pack and increase the size we will see an even greater disparity in sales.

 

[Nubo]

Yes, edge case. I don't give a damn about a solitary person named Jennifer in Arizona. The typical LEAF is charged once per day overnight. Multiple quick charges in succession are an edge case.

Whether your case is typical or even universal, the fact that Nissan appears to have increased the coddling of the battery, raises the question of whether this battery NEEDS more coddling because it is a weakling, or is Nissan simply being more conservative than in the past? Given Nissan's history with batteries this is information relevant to many potential buyers.

 

[Joe6pack]

I am not going to argue with a pedantic Internet troll whose primary purpose is to sow fear and doubt. The fact is you're wrong.

Fear and doubt? How about facts. Go read my other post to you in another thread, I'm not sowing fear or doubt just stating facts that anyone can validate and others understand. I don't care who makes the EV, without proper cooling you can't repeatedly QC a pack and the more that pack is stacked the less that heat will dissipate. Just because you may not need to QC multiple times or you think that is fringe or not for the average user does not change the actual facts. There are many people in market for an EV that don't understand this and would be very unhappy to know this limitation because it impacts their needs. Again, I have been a LEAF proponent since 2011 but I'm not going to act like a fanboy and defend packs that degrade fast or QC limitations. Just like Tesla made stupid mistakes with parasitic loads on pre 2015 cars I would call them out on it, at least they admitted and fixed it. The LEAF is not well designed for multiple QC events period, if you think that's not true then ask Nissan why they admit and state that. There is no new news here it's part of the original design and no surprise and has been an issue at a lower level for a long time, this is a function of design clearly as you can't heat a large sealed brick and expect it to cool quickly.

I would not call this a new issue but more something many people are not aware of on a comparative basis from EV to EV. For my needs and others this won't work even with a very good QC network because I don't have the desire to wait long times because of throttles charge rates. The larger pack allows longer travel distances which opens the perception of long distance travel but the reality is there are penalties that may not be present on other cars or experienced during shorter trips. Good luck driving long distance in hot weather up any substantial or even moderate grades without long charge times that are likely not anticipated. All this will go away when they cool the pack and everyone will see HUGE disparity in the cars, if they don't cool the pack and increase the size we will see an even greater disparity in sales.

And I am still going to say that it is an edge case even for the 2018. At 150 miles it is still considered a short-range EV.

Here are some other contentions that are not necessarily facts:

Heat Generation: There is nothing to indicate that the new battery will internally generate heat any greater than the older 30 or 24 kWh packs. An increase in capacity does not inherently mean more internal heat generation. There are too many other factors including battery chemistry, internal resistance, and taper to know whether or not this battery is better or worse for heat generation while quick charging or under normal discharge conditions. We do not have any empirical data to indicate that the 2018 battery is worse for internal heat generation.

Heat Dissipation: Once again, there is nothing, in my opinion, about the 2018 LEAF battery that indicates it will retain heat better or worse than the previous 30 or 24 kWh batteries. We do not know the differences in geometry, mass, thermal capacitance or thermal resistance. We do not have any empirical data to indicate that the 2018 battery is better or worse for heat retention.

Degradation: Who knows? This is a new pack and presumably has different chemistry (cathode, anode, electrolyte) from the previous packs. It is reckless to assume that the past behavior of different packs with different chemistries is indicative of future behavior of the new 2018 LEAF pack. It is downright dishonest to state that the new LEAF has battery degradation issues in an effort to deter potential EV buyers from considering the new LEAF.

And now, here is an actual fact:

The limited Nissan LEAF® lithium-ion battery warranty includes coverage for defects in materials or workmanship for 8 years / 100,000 (whichever occurs first) miles as well as protection against capacity loss below 9 bars of capacity (out of 12) as shown on the LEAF’s capacity gauge for a period of 5 years / 60,000 miles (whichever occurs first). For complete information concerning coverage, conditions and exclusions, see your Nissan dealer and read the actual New Vehicle Limited Warranty booklet.