2019/2020 Leaf

[Kenneth Bokor]

A 2019 Leaf was spotted in a charger test. It seems that the 2019 leaf does use LG battery modules, has active TMS, and can charge at 100KW rate. It was spotted at a Charger Manufacturer undergoing testing. The battery is approximately 60KWH and the onboard charger is either 11KW or 22KW. The 11KW charger is probably for the US market while the 22KW charger is likely for multi-phase charging in Asia and Europe. 11KW is enough to charge to 100% overnight anyway. 22KW charging could be 480VAC single phase as well but that tends to be an industrial voltage.

Here is link to article.

https://electrek.co/2018/07/06/nissan-l ... -charging/

Hope it is real.

 

[Pushmi-Pullyu]

It seems that the 2019 leaf does use LG battery modules, has active TMS...

That's been the rumor for some time now. Supposedly, the 2019 Leaf will have two battery pack sizes, and the larger one will come with an active TMS. I hope that turns out to be true!

It will also be quite important if Nissan starts using LG Chem batteries as a standard for the Leaf. It's been pointed out that the VW eGolf, like the Leaf, doesn't have an active TMS, yet we don't see lots of reports about premature battery fading in the eGolf. The logical conclusion -- perhaps not correct, but logic suggests -- that Nissan picked a very poor battery chemistry for the Leaf and then compounded that problem by not putting an active TMS into the car.

Here's hoping Nissan turns both situations around! If it doesn't, then the Leaf is going to rapidly be seen as more and more obsolete in the next few years.

​

 

[Paul K]

And it goes on and on. Endless battery bashing for no tms. My 2016 30kwh Leaf pack is in great shape. I suggest the folks not sure about this issue should see my thread "managing with tms" in the Forums/Nissan/Leaf. The best tool for the job is the simplest one. No tms means some one like me could afford an electric car. It does the job. I did my homework. No tms no problem for this owner.

 

[marshall]

And it goes on and on. Endless battery bashing for no tms. My 2016 30kwh Leaf pack is in great shape. I suggest the folks not sure about this issue should see my thread "managing with tms" in the Forums/Nissan/Leaf. The best tool for the job is the simplest one. No tms means some one like me could afford an electric car. It does the job. I did my homework. No tms no problem for this owner.

How many miles on the car? And what in the heck does great shape mean?

 

[Paul K]

How many miles on the car? And what in the heck does great shape mean?

34,000K which comes to a little over 20,000 miles. Great shape means all capacity bars showing. I may have lost about 5% range since new based on
what the GOM shows when I charge to full but I haven't had the software calibration update for the 30kwh done yet. The car is parked outdoors year round which means blistering heat (not bad as sun belt states) and winter temps as low as -30C. Read the post "managing with tms" in the forums Nissan/Leaf. I am by no means carrying a torch for Nissan but so far this car has not given me any reason not to buy another Leaf in 2020 if competitive.

 

[Pushmi-Pullyu]

Read the post "managing with tms" in the forums Nissan/Leaf. I am by no means carrying a torch for Nissan but so far this car has not given me any reason not to buy another Leaf in 2020 if competitive.

You make it sound like all you need to do, to keep the Leaf battery pack from prematurely aging, is to live in a climate where it never gets overly hot, and treat the battery with some respect... i.e., avoid fast charging and don't abuse it by running it down so far the car goes into turtle mode.

Unfortunately, your argument is sharply contradicted by, for example, reports from people who have bought a second Leaf after having had a good experience with the first, and found to their dismay that even though they didn't change their driving habits, the battery pack in their second Leaf experienced premature aging. That includes some Leaf drivers who live in northerly, colder climates such as Michigan and southern Canada.

I'm glad that you personally have not had that problem, but applying some critical thinking to the various reports we've seen, it very much appears that it's largely a matter of random chance as to whether any individual Leaf's battery pack will experience premature aging or not. Perhaps there is a lack of consistency in manufacturing the battery cells? I dunno.

At any rate, it's great that Nissan is finally moving to put an active TMS into their Leaf, even if it's only the higher trim level, larger battery pack version. Hopefully in future years they will make a TMS standard equipment in all Leafs, regardless of trim level.

​

 

[Paul K]

You make it sound like all you need to do, to keep the Leaf battery pack from prematurely aging, is to live in a climate where it never gets overly hot, and treat the battery with some respect... i.e., avoid fast charging and don't abuse it by running it down so far the car goes into turtle mode.

Unfortunately, your argument is sharply contradicted by, for example, reports from people who have bought a second Leaf after having had a good experience with the first, and found to their dismay that even though they didn't change their driving habits, the battery pack in their second Leaf experienced premature aging. That includes some Leaf drivers who live in northerly, colder climates such as Michigan and southern Canada.

I'm glad that you personally have not had that problem, but applying some critical thinking to the various reports we've seen, it very much appears that it's largely a matter of random chance as to whether any individual Leaf's battery pack will experience premature aging or not. Perhaps there is a lack of consistency in manufacturing the battery cells? I dunno.

At any rate, it's great that Nissan is finally moving to put an active TMS into their Leaf, even if it's only the higher trim level, larger battery pack version. Hopefully in future years they will make a TMS standard equipment in all Leafs, regardless of trim level.

​

I always read your posts with great interest and respect. One of the things I was hoping for when I posted my thread on the forums was to hear feedback from Leaf owners both good and bad with their battery experiences. So far I've had neither. So yes, some people have experienced premature battery aging but how do we find what the real numbers are? I fully expected angry Leaf owners to rip into my post and it hasn't happened. I would love to have a handle on whether the battery issues are causal or random. BTW we're in a heat wave right now where advisories are issued warning people with heat tolerance problems to take shelter. Still my Leaf hasn't gone over 6 temp bars out of 12 even with freeway driving. The only time I've gone above 6 bars is when I experimented with a DCFC top up and I went to 7. In all fairness I was only topping up and not going from 20% to 80% so I don't know what that would do. Remember pupu this is a young technology and there are bound to be speed bumps and glitches along the way. As much as I admire Tesla the products are out of my price range while the non tms Leaf is just affordable. It isn't the car for everyone but what car is?

 

[Pushmi-Pullyu]

I always read your posts with great interest and respect.

That's very kind of you, sir! Thank you.

One of the things I was hoping for when I posted my thread on the forums was to hear feedback from Leaf owners both good and bad with their battery experiences. So far I've had neither.

This forum has managed to attract a very active community of Clarity PHEV owners, probably because it's a pretty new entry into the PEV field and no other forum had already established a community for the Clarity PHEV, and because those who first posted here were made welcome and encouraged to make their own space here.

Contrariwise, the Leaf is long established, and probably Leaf owners already have their "go-to" forum for discussion of their cars. Since my personal focus is on Tesla, I'm not really familiar with Leaf forums, but even I have been known to cite from posts to the My Nissan Leaf.com forum, and I believe that there is also a very active Leaf section of the GM-Volt.com forum.

As much as I admire Tesla the products are out of my price range while the non tms Leaf is just affordable. It isn't the car for everyone but what car is?

Well, we all should take care to differentiate between fact and opinion, as part of practicing critical reading. When I say the non-TMS Leaf will rapidly become obsolete, that's just an opinion, and possibly a wrong one. Certainly Nissan has done a great job capturing the bottom end of the full-sized BEV market. Perhaps the market will remain even after there are a lot of new entries from other auto makers, which is already happening, but will sharply accelerate starting in 2020.

I think even if Nissan continues making lower trim Leafs without active TMS, they're going to have a hard time competing with Chinese made BEVs, once those cars start entering the American and European markets. The Trumpian trade war may delay that entry, but thankfully he won't be in office forever... Well, a rant about that would be completely off-topic for this thread. Anyway, sooner or later Nissan is going to start getting competition from Chinese auto makers in the bottom end of the international BEV market. I don't think they are going to be able to maintain their lead in that segment of the market once they have competition from the Chinese.

Again, all just my opinion.

I'm glad you're enjoying your Leaf, and I hope you have many years of happy driving with it!

 

[Pushmi-Pullyu]

So yes, some people have experienced premature battery aging but how do we find what the real numbers are?

Here you cut to the heart of the matter. Like you, I've always wondered just how often premature Leaf battery pack fade actually occurs. What percentage of Leaf owners have had premature loss?

Unfortunately, on that it seems the Internet isn't very helpful. I've never seen anybody attempt an actual survey of Leaf owners to find out just how many of them have had bad experiences. I think we all know that people who are merely content with their experience rarely post about it online; it's only those who have especially good or especially bad experiences who tend to spend the time and effort to post about their experience online. So, just as I think you're suggesting or saying, anecdotal evidence about premature battery fade in the Leaf may be giving us a skewed idea of just how frequently that occurs. There have been enough reports from all over that I feel fairly confidence that it's not just a few isolated incidents, but given the large volume of sales, just a few percent (perhaps less than 10%... or who knows? Maybe even less than 5%) might be generating the volume of complaints we've seen.

If you do find any source that you think appears to be even somewhat authoritative or at least plausible in estimating the actual percentage or fraction, then I hope you'll post it here for us to read!

​

 

[Kenneth Bokor]

Exactly PP, that is the real meat of the matter. I hear all this bashing but the reality is that very few Leaf owners have had serious problems with their Leafs, in comparison to the over 320,000 Leafs delivered globally by Nissan since 2010. Even if 500 or 1000 owners have had serious problems (early battery degradation needing battery pack full/partial swaps under warranty, etc.), that number relative would be extremely low, like less than 1%.

This is the perspective I keep telling everyone. Look at Ford, GM, FCA, Tesla, Kia, etc. in recalls they have gone thru and many more bad experiences customers have gone thru, especially from the big 3. And this is for ICE cars - you would think after 100 years of the ICE car being built, that they would get it right by now!!

As Paul states, BEV technology is still in it's infancy (10 years) when compared to ICE timelines.

So I really don't believe all this negative BS about Leaf and bad battery and early failures due to no ATM - the Leaf DOES have BMS (Battery Management System) - the current MY2018 throttles down Rapid Charging based on battery temps to protect it!! If that is not BMS, then I don't know what is!

What they do NOT have is Active Thermal Management - just PTM - Passive Thermal Management.

Additionally, I am 100% sure that Nissan will continue with future BEV models that DON'T offer ATM as well - in order to keep costs down and provide more affordable pricing and product to the everyday consumer. That is why IMO they are really more of a mass-market BEV supplier than Tesla is - their BEVs are more affordable and are marketed to a different consumer base than Tesla is. The only reason Tesla will (if they have not already) surpass Nissan for Global Sales and take the lead, is because they are cranking out more BEVs than Nissan is. If Nissan could crank out 5,000 per week in every plant, they would sell 200,000 Leafs or more a year. So it is a supply and delivery purposeful restraint by Nissan, IMO.

Look, I am supportive of all the manufacturers of BEVs/EVs as this is the future of consumer transportation. Tesla has ignited the marketplace, thru the spark of the Model 3, and it is now exploding with almost all the major automobile manufacturers expanding their portfolios for electrification - some going all in. We need more choice in the marketplace, and I can bet that it won't come from China. No one outside of that market (like North America or EU) will buy BEV's from there in any mass quantity. Won't happen.

The ROW EV growth will come from the mainstream manufacturers and other BEV only companies (like Tesla).

I personally asked a senior person at Nissan about their battery reported woes of the Leaf, and I was told that they have NEVER had one serious failure of a pack. No fires, no serious failures - not one. That is something they have publicly stated as well.

So please, get off of this bandwagon of BS regarding the "Leaf battery is terrible because it does not have ATM" and look at the reality. I've talked to many Leaf owners and the vast majority love the car and would buy another in a heartbeat. This is of course not a true representation of Nissan's full Leaf installed base, but at least it is something.

The forums are full of a majority of people that just want to bash and complain and scream loudly about something, hence why I stay off of most of them. I find this forum to be more objective and tolerable so am more active here than others.

Hope this info is helpful and I am not picking on you PP directly, just trying to point out some of my observations that I've been spreading on the other forums, only to get ostracized so I left them.

Oh and don't get me wrong, Nissan is not perfect and I am sure there are some issues. Just that it is not as big as an issue as many make it out to be...IMO.

 

[Paul K]

Exactly PP, that is the real meat of the matter. I hear all this bashing but the reality is that very few Leaf owners have had serious problems with their Leafs, in comparison to the over 320,000 Leafs delivered globally by Nissan since 2010. Even if 500 or 1000 owners have had serious problems (early battery degradation needing battery pack full/partial swaps under warranty, etc.), that number relative would be extremely low, like less than 1%.

This is the perspective I keep telling everyone. Look at Ford, GM, FCA, Tesla, Kia, etc. in recalls they have gone thru and many more bad experiences customers have gone thru, especially from the big 3. And this is for ICE cars - you would think after 100 years of the ICE car being built, that they would get it right by now!!

As Paul states, BEV technology is still in it's infancy (10 years) when compared to ICE timelines.

So I really don't believe all this negative BS about Leaf and bad battery and early failures due to no ATM - the Leaf DOES have BMS (Battery Management System) - the current MY2018 throttles down Rapid Charging based on battery temps to protect it!! If that is not BMS, then I don't know what is!

What they do NOT have is Active Thermal Management - just PTM - Passive Thermal Management.

Additionally, I am 100% sure that Nissan will continue with future BEV models that DON'T offer ATM as well - in order to keep costs down and provide more affordable pricing and product to the everyday consumer. That is why IMO they are really more of a mass-market BEV supplier than Tesla is - their BEVs are more affordable and are marketed to a different consumer base than Tesla is. The only reason Tesla will (if they have not already) surpass Nissan for Global Sales and take the lead, is because they are cranking out more BEVs than Nissan is. If Nissan could crank out 5,000 per week in every plant, they would sell 200,000 Leafs or more a year. So it is a supply and delivery purposeful restraint by Nissan, IMO.

Look, I am supportive of all the manufacturers of BEVs/EVs as this is the future of consumer transportation. Tesla has ignited the marketplace, thru the spark of the Model 3, and it is now exploding with almost all the major automobile manufacturers expanding their portfolios for electrification - some going all in. We need more choice in the marketplace, and I can bet that it won't come from China. No one outside of that market (like North America or EU) will buy BEV's from there in any mass quantity. Won't happen.

The ROW EV growth will come from the mainstream manufacturers and other BEV only companies (like Tesla).

I personally asked a senior person at Nissan about their battery reported woes of the Leaf, and I was told that they have NEVER had one serious failure of a pack. No fires, no serious failures - not one. That is something they have publicly stated as well.

So please, get off of this bandwagon of BS regarding the "Leaf battery is terrible because it does not have ATM" and look at the reality. I've talked to many Leaf owners and the vast majority love the car and would buy another in a heartbeat. This is of course not a true representation of Nissan's full Leaf installed base, but at least it is something.

The forums are full of a majority of people that just want to bash and complain and scream loudly about something, hence why I stay off of most of them. I find this forum to be more objective and tolerable so am more active here than others.

Hope this info is helpful and I am not picking on you PP directly, just trying to point out some of my observations that I've been spreading on the other forums, only to get ostracized so I left them.

Oh and don't get me wrong, Nissan is not perfect and I am sure there are some issues. Just that it is not as big as an issue as many make it out to be...IMO.

 

[Paul K]

Well said Kenneth. I too get turned off by the negative bile spewers in comment sections. It seems that some people can only achieve a sense of self importance by dumping all over the creations or opinions of others. My car has been called: ugly, looks like a frog, a turd, etc. My nature is such that the more it got bashed the more I would like it. In spite of the high temperatures this week I have not gone above 6 battery temp bars in everyday use. Today I was hoping to use a fast charger on my route to see how much of a temp rise I would get but (surprise surprise) it was out of order.

I can't get my head around how battery packs could fail randomly. There are thousands of individual cells in the pack modules which could by themselves become defective, but for an entire pack to start going down the drain, something would have to be happening to a majority of the cells. And what might that be? I strongly suspect over heating as a result of long distance high speed driving and regular use of DCFCs on these runs.

I was hoping to experiment with this (only a few times) and report to this forum but may soon lose the opportunity to do it with the current vehicle. I most certainly didn't want to trade in after only 2 years, but with imminent election of the Ford conservatives coming I placed a deposit on a new 40kwh 2018 Leaf at the end of April. The extra range would come in handy in bitter cold and the $14,000 incentive was too good to pass up. Then Ford cancelled the incentives and I though that was the end of it. Then I get a call from the dealer that there had been some last minute changes and if they got the info in by a certain date, those orders would still receive the incentive and mine was among them. I'll bet there would have been hundreds if not thousands of Leafs sitting unsold on dealer's lots as a result of this and I'll bet my boots that the majority of car dealers vote conservative.

Very mixed feelings about this. While the extra range will be great, I don't like the dash display of the new Leaf or it's "blend in" appearance. Yes sir the old Leaf's appearance was a bit of a stand out but I use mine for business complete with magnetic signs. So a look that gets more attention? All the better. Take that trolls!

 

[Kenneth Bokor]

Thanks Paul for the comments and all your info on this subject. Great to hear you are getting the New Leaf, I am sure you will love it. Would welcome the chance to get together once you get it to help you go over the display, etc. You can email me at [email protected]. I'm hoping to plan an EV meet up and cruise next month or in Sept, so would like to add you to my list!

 

[Pushmi-Pullyu]

As Paul states, BEV technology is still in it's infancy (10 years) when compared to ICE timelines.

Yes, and this is something that I think most people -- even a lot of EV supporters -- don't fully appreciate; that plug-in EV tech is still a relatively new and undeveloped technology. ICEV manufacturers have had, as you say, more than a century to perfect the gasmobile, to iron out the problems and reduce the cost of manufacturing. When we learn that a typical gas engine has 200-300 moving parts, the fact that such an engine can be made for just a few hundred dollars is astonishing.

Who knows what EVs will be like a century from now? Well, I certainly won't be around to see that! But I know that they will be as much improved over today's BEVs as today's gasmobiles are improved over pre-Model T motorcars.

So I really don't believe all this negative BS about Leaf and bad battery and early failures due to no ATM - the Leaf DOES have BMS (Battery Management System) - the current MY2018 throttles down Rapid Charging based on battery temps to protect it!! If that is not BMS, then I don't know what is! What they do NOT have is Active Thermal Management - just PTM - Passive Thermal Management.

Well, all li-ion battery packs have to have a BMS. Not having one leads to escalating imbalance in the pack and that leads to rapid premature aging.

By the way: The usual acronym for an active thermal management system is TMS. You are of course free to make up whatever TLAs (Three Letter Acronyms) you want , but it would help people understand what you're saying if you stick to common terms.

If Nissan could crank out 5,000 per week in every plant, they would sell 200,000 Leafs or more a year. So it is a supply and delivery purposeful restraint by Nissan, IMO.

I don't think so. The Leaf's global sales maxed out at about 100,000. Nissan is selling less now because demand has dropped from that peak, not because they are supply constrained. At least, that's my understanding. If you have some hard data or well-supported evidence to indicate otherwise, I'd certainly be interested in seeing it.

Hope this info is helpful and I am not picking on you PP directly, just trying to point out some of my observations that I've been spreading on the other forums, only to get ostracized so I left them.

I don't feel "picked on" at all by your comments, Kenneth. Not even remotely. And I hope you don't feel picked on by anyone here, either. We all should value different opinions; we are stronger through diversity than we are by all rigidly thinking alike. America became a Great Nation through contributions from the "melting pot" of immigrants from all parts of the world, not by making America "safe" for just one ethnic group.

Those are principles all too often forgotten in our increasingly tribalistic culture. How boring the world would be if everyone thought the same about everything!

Okay... down off my soapbox now.

I do wonder if the general attitude among many on this forum, that the Leaf is not a very good EV, has lead to a lack of participation by Leaf owners here. There is a very notable lack of discussion about the Leaf. Well, I hope it's because there are already long-established forums for discussion of the Leaf, and not because Leaf owners feel unwelcome here. As you say, Kenneth, the Leaf is to date the world best-selling BEV, at least in first-world countries, so there must be a very large number of people who are quite happy to be driving one!

I have an issue -- a serious issue -- with those who appear to be saying things they don't honestly believe, and making false claims, to bash EVs. Bashing EVs in general or bashing one specific company. Admittedly I don't always correctly identify who is giving their honest opinion and who isn't, because serial bashers (FUDsters) almost always try to pass themselves off as those giving their honest opinions or concerns (hence the term "concern trolls"). But it's pretty clear to me that you are giving us your honest opinions, and we all should respect that.

Thanks for sharing, and I hope you will continue to contribute to this forum!

 

[Pushmi-Pullyu]

I can't get my head around how battery packs could fail randomly. There are thousands of individual cells in the pack modules which could by themselves become defective, but for an entire pack to start going down the drain, something would have to be happening to a majority of the cells. And what might that be?

Before I venture an opinion, I need to make very clear that I have no claim to expertise regarding li-ion battery tech, and I've seen nothing but questions about why this happens more than just occasionally in Leaf battery packs. I can talk with some confidence about some aspects of li-ion battery pack tech, from all that I've read on the subject, but whether or not any of the points I make below is actually related to the cause of premature Leaf battery pack fade is entirely speculation on my part.

The reason a li-ion pack has to have a BMS (Battery Management System) is to keep the cells balanced, so no one cell in the pack has significantly more or less voltage than any other. If one of them does, the entire pack gets out of balance, which leads to rapid premature aging. I don't understand why this is, but that's what the experts say. One problem is that battery pack discharging stops when any one cell in the pack reaches minimum safe voltage, so if one cell is damaged and weakened, that causes the entire pack to stop discharging while the rest of the cells still have a significant amount of charge left... which would show up as premature loss of capacity.

For those interested, more details on the subject can be found here: "Why Proper Cell Balancing is Necessary in Battery Packs"

If -- and again this is speculation on my part, and no one else's -- if one of the cells in a Leaf pack were to get seriously out of balance, and if the pack isn't able to deal with that situation, then that could lead to exactly the sort of apparently random cases of premature aging we've seen reported for Leaf packs.

Tesla's packs are designed so that if one cell gets seriously out of balance or otherwise malfunctions, the BMS will cut that individual cell out of the circuit. Of course it's not fair to compare the Leaf to the much more expensive Tesla cars, but I know a lot more about Tesla's tech than other BEV tech, so I have an informed opinion on the subject; I'm far less knowledgeable about the Leaf. If -- again, this is speculation -- if Nissan hasn't designed the Leaf pack so that the BMS can cut individual cells out of the circuit, that might explain why a single cell going bad could cause premature aging of the entire pack.

 

[Kenneth Bokor]

Yes, and this is something that I think most people -- even a lot of EV supporters -- don't fully appreciate; that plug-in EV tech is still a relatively new and undeveloped technology. ICEV manufacturers have had, as you say, more than a century to perfect the gasmobile, to iron out the problems and reduce the cost of manufacturing. When we learn that a typical gas engine has 200-300 moving parts, the fact that such an engine can be made for just a few hundred dollars is astonishing.

Who knows what EVs will be like a century from now? Well, I certainly won't be around to see that! But I know that they will be as much improved over today's BEVs as today's gasmobiles are improved over pre-Model T motorcars.



Well, all li-ion battery packs have to have a BMS. Not having one leads to escalating imbalance in the pack and that leads to rapid premature aging.

By the way: The usual acronym for an active thermal management system is TMS. You are of course free to make up whatever TLAs (Three Letter Acronyms) you want , but it would help people understand what you're saying if you stick to common terms.



I don't think so. The Leaf's global sales maxed out at about 100,000. Nissan is selling less now because demand has dropped from that peak, not because they are supply constrained. At least, that's my understanding. If you have some hard data or well-supported evidence to indicate otherwise, I'd certainly be interested in seeing it.



I don't feel "picked on" at all by your comments, Kenneth. Not even remotely. And I hope you don't feel picked on by anyone here, either. We all should value different opinions; we are stronger through diversity than we are by all rigidly thinking alike. America became a Great Nation through contributions from the "melting pot" of immigrants from all parts of the world, not by making America "safe" for just one ethnic group.

Those are principles all too often forgotten in our increasingly tribalistic culture. How boring the world would be if everyone thought the same about everything!

Okay... down off my soapbox now.

I do wonder if the general attitude among many on this forum, that the Leaf is not a very good EV, has lead to a lack of participation by Leaf owners here. There is a very notable lack of discussion about the Leaf. Well, I hope it's because there are already long-established forums for discussion of the Leaf, and not because Leaf owners feel unwelcome here. As you say, Kenneth, the Leaf is to date the world best-selling BEV, at least in first-world countries, so there must be a very large number of people who are quite happy to be driving one!

I have an issue -- a serious issue -- with those who appear to be saying things they don't honestly believe, and making false claims, to bash EVs. Bashing EVs in general or bashing one specific company. Admittedly I don't always correctly identify who is giving their honest opinion and who isn't, because serial bashers (FUDsters) almost always try to pass themselves off as those giving their honest opinions or concerns (hence the term "concern trolls"). But it's pretty clear to me that you are giving us your honest opinions, and we all should respect that.

Thanks for sharing, and I hope you will continue to contribute to this forum!

Thanks for your opinions too. And noted: TMS.

 

[Kenneth Bokor]

Before I venture an opinion, I need to make very clear that I have no claim to expertise regarding li-ion battery tech, and I've seen nothing but questions about why this happens more than just occasionally in Leaf battery packs. I can talk with some confidence about some aspects of li-ion battery pack tech, from all that I've read on the subject, but whether or not any of the points I make below is actually related to the cause of premature Leaf battery pack fade is entirely speculation on my part.

The reason a li-ion pack has to have a BMS (Battery Management System) is to keep the cells balanced, so no one cell in the pack has significantly more or less voltage than any other. If one of them does, the entire pack gets out of balance, which leads to rapid premature aging. I don't understand why this is, but that's what the experts say. One problem is that battery pack discharging stops when any one cell in the pack reaches minimum safe voltage, so if one cell is damaged and weakened, that causes the entire pack to stop discharging while the rest of the cells still have a significant amount of charge left... which would show up as premature loss of capacity.

For those interested, more details on the subject can be found here: "Why Proper Cell Balancing is Necessary in Battery Packs"

If -- and again this is speculation on my part, and no one else's -- if one of the cells in a Leaf pack were to get seriously out of balance, and if the pack isn't able to deal with that situation, then that could lead to exactly the sort of apparently random cases of premature aging we've seen reported for Leaf packs.

Tesla's packs are designed so that if one cell gets seriously out of balance or otherwise malfunctions, the BMS will cut that individual cell out of the circuit. Of course it's not fair to compare the Leaf to the much more expensive Tesla cars, but I know a lot more about Tesla's tech than other BEV tech, so I have an informed opinion on the subject; I'm far less knowledgeable about the Leaf. If -- again, this is speculation -- if Nissan hasn't designed the Leaf pack so that the BMS can cut individual cells out of the circuit, that might explain why a single cell going bad could cause premature aging of the entire pack.

Hi well I am certainly NOT a battery expert nor an engineer. However, there is info out there and I came across this informative video which uses relatively similar Leaf battery packs (from a 24 kWh Leaf) without BMS.



If you read some of the comments, there are statements indicating that a BMS is not needed in many circumstances. However, that is not to say that the Leaf does not have a BMS. As you mentioned, keeping cells balanced seems to be critical to maintaining a healthy pack. One comment mentioned the use case of pushing batteries to their limits frequently, can lead to unbalanced situations.

I believe Paul and I as well have heard this from others that it is thought that many of the reported pack cell problems by Leaf owners, are caused by those same owners "hammering their packs" a lot. Many and frequent rapid charges as well as fast driving speeds, frequent quick starts (like gunning it at a light), etc. I think some of the reported issues can be attributed to this kind of behaviour of the owner and use of the Leaf.

It's kinda like the redline in a ICEV - if you drive it close to the redline RPMs all the time, the engine is going to break somewhere earlier then it normally would have.

I don't think the Leaf is battery pack is built for this kind of continuous use since it clearly does not have a TMS, but relies solely on passive techniques. We know that any BEV with an active TMS that deploys cooling/heating with liquid or other, can stand up to this kind of wear and tear much better than a BEV that does not have this engineering.

As I've stated, I am only 2+ months into my first BEV ownership, which happens to be a 2018 Leaf. I drive normally and actually somewhat slower and easier then I would in my other ICE car, as I am conscious of the battery and don't want to purposely do anything long term that can lead to any issues. I use the power when I need it but don't hammer it all the time. I don't rapid charge very much (maybe a few times a year), as 95% of my daily driving is well within even winter temp ranges, so home charging at 6.6 kWh is my norm.

Hopefully with my use case, I won't have any abnormal issues with my Leaf's batteries over time. However, I will have to wait and see.

We know that the MY2018 Leaf has a more dense pack, with 8 cells per module (24 Modules) versus the previous 4 cells per module (48 Modules) - in the same physical size space. Both packs have same total number of cells at 192 with the 40 kWh cells being 0.9mm thicker providing more density therefore more energy storage. Coupled with an improved cell chemistry providing higher capacity material adoption (N/M/C), the new pack achieve a +67% higher capacity and +37% higher output versus the 24 kWh pack and 33% greater energy density over the 30 kWh pack. Of course more density/energy from same physical space will create more heat, hence the necessity for Nissan's adoption of rapid charge throttling in the new Leaf, in order to protect the pack/modules/cells from overheating and damage. This so called "rapidgate" is really nothing more than purposeful engineering by Nissan which they should have and be honestly informing buyers of, so they can make informed decisions up front. Some viewed mis-leading advertising has also contributed to the "rapidgate" movement, which does not help Nissan and the way many view them.

I've actually spoke to a few people at Nissan Canada, Nissan UK as well as communicated to Nissan HQ in Japan regarding this negative viewpoint and what Nissan can do to fix it and hope they will adopt some of my recommendations.

In the meantime, Nissan will continue to sell as many Leafs as they can produce in the majority of global markets they support, since it hits a sweet spot of EV adopters (like me) which I believe are the vast majority of prospects that Nissan has targeted with the MY2018 Leaf.