Tesla CEO Rips on Nissan's Battery Technology, Says It's "Primitive"

· · 4 years ago

According to reports, Tesla CEO Elon Musk said that he's not worried about being beaten by other companies on a cost per kWh basis when it comes to batteries. In particular, when pressed about the amazing price point Nissan seems to have attained with the batteries that will go in the LEAF (perhaps even as low as $375 per kWh), Musk reportedly said that Nissan uses a “much more primitive level of technology.”

Musk believes that because Nissan's battery pack is passively air cooled instead of actively liquid cooled—like Tesla's battery packs—the LEAF's battery temperature will be “all over the place,” and result in “huge degradation.” In addition, Musk reportedly believes that the LEAF will not be able to operate in cold environments and will “shut off” in hot environments. In the past, Nissan has said they are extremely confident that the LEAF batteries will perform reasonably well in both hot and cold environments, but that it will likely see a performance reduction to some degree when operating at extremes.

Given that the LEAF has an 8 year/100,000 mile warranty on its battery pack, whereas the Tesla Roadster only has a rather standard 3 year/36,000 mile warranty, I'm not sure if Musk has much to stand on here. Nissan's Mark Perry recently said that their design mantra was to keep the LEAF as simple as possible and that adding in a liquid cooling system would have added significant expense. He also told me that with Nissan's 20 year history of battery design, they felt confident that their battery pack would withstand the daily grind even without the liquid cooling. According to Perry, future generations of the LEAF will have some kind of active cooling, but it will likely still be air driven and not liquid.

Musk and Tesla are in the initial stages of gearing up for production of the Model S, an electric luxury family sedan due in 2012. At nearly $58,000, Musk hopes the S will finally turn Tesla into a profitable company. Musk said that the battery costs for the Model S are on track to be 40% less than for the Roadster. Even so, it's unclear why Musk is picking on the LEAF given that the two companies, for the foreseeable future, won't even be competing in the same category.

Source: Earth2tech

Image Credit: Some rights reserved by jurvetson via Flickr

Comments

· · 4 years ago

I'm no expert on batteries. In fact, the conversations I see experienced EV-ers having about things like battery cooling systems online make my head spin. But the criticism Musk delivers makes me nervous. Not necessarily because if I buy a LEAF it will suddenly stop running on one of our 100-degree Denver days, but because if this happens to a lot of people, it will do untold damage to public perception of plug-in vehicles.

Maybe that's what Musk is worried about, and it's the primary motivation for his critique of the LEAF pack, though his could be another motivation.

I, for one, definitely don't want Nissan, or anyone else, coming out with a plug in whose battery pack fails too often and thereby deeply undermines public confidence in plug-ins in general, whether they're a Nissan, Mitsubishi, Ford, or Tesla.

· Eric (not verified) · 4 years ago

The Volt pack is liquid cooled, right? What about the Ford Focus Electric?

· Anonymous (not verified) · 4 years ago

i would worry if you live in really hot /cold weather I think air cooled EV do better in 70 degree weather or get a themo gel cooled wrap on the battery and pay more money for it- like some ev's out there, yes volt is and tesla is too.

· TrasKY (not verified) · 4 years ago

It's probably a defensive thing. Reading the comments, I would imagine that Tesla, selling a luxury car and having no room to loose money is using a more surefire battery design, charging a premium and not ladling on the warranty. Meanwhile, Nissan, with a bit of cash to burn on this first generation, is probably over-promising on the warranty and is already talking about how the battery design will change but they just need to get these things out on the road. GM will take their loss when the cars come off their lease. Nissan is probably already banking on replacing a bunch of batteries with a second generation design which they are already working on. Tesla can't play games. So they have tough talk.

· · 4 years ago

For the record, the longest-lasting EV of the 1990's is the Rav4EV. The car that my family has been driving almost every day for over eight years. The NiMH batter pack is air cooled... and poorly at that. Any design that takes more care than Toyota did with these packs doesn't have all that much to get excited about. Yes, active liquid cooling is better for the batteries. And it comes at a high cost. Is 10% longer life worth 50% more money? (just to grab numbers out of my hat). That's the decision that needs to be made by the makers.

The bottom line is that we won't know about battery life until they've had a chance to live. Nobody (definitely including Toyota) thought the Rav4EV batteries would last this long.... yet here we are with many of the cars having driven well over 100,000 miles on the original packs.

· Charles Whalen (not verified) · 4 years ago

I would like to respond to a couple of my esteemed EV colleague (and he truly *is* highly esteemed in the EV universe) Darell’s points:

> The bottom line is that we won't know about battery life
> until they've had a chance to live.

True, in a real-world sense. But we’ve got a pretty good idea about this and a lot of very detailed, in-depth, extensive empirical studies and hard-core science on this (specifically, lithium battery life as a function primarily of long-term ambient temperature exposure over time, and secondarily, of average SOC over time) conducted and published in dozens of technical papers on this exact subject over the last decade by leading battery engineers and scientists at Argonne National Labs (Ira Bloom et al), NREL (Kandler Smith, Ahmad Pesaran, et al), Idaho National Labs (Jon Christophersen et al), Lawrence Berkeley National Labs (Vince Battaglia et al), and Sandia National Labs (Dan Doughty et al), … some of which are available on some of those labs’ respective websites and many others of which are available for purchase online from the archives of the Journal of Power Sources (just do an author search on any of those authors and you will see dozens of technical papers on this particular subject).

For instance, just a couple of basic technical papers on this subject are:

“PHEV Battery Trade-Off Study and Standby Thermal Control”, presented at the 26th International Battery Seminar & Exhibit, Fort Lauderdale, FL, March 16-19, 2009, by Kandler Smith, Tony Markel, and Ahmad Pesaran of NREL,

and

“Battery Thermal Issues and Solutions for PHEVs”, presented at Plug-In 2009 in Long Beach, CA, August 10-13, 2009, by Ahmad Pesaran of NREL.

> Yes, active liquid cooling is better for the batteries.
> And it comes at a high cost. Is 10% longer life worth 50%
> more money? (just to grab numbers out of my hat).
> That's the decision that needs to be made by the makers.

I think Darell’s numbers that he “just grabbed out of his hat” -- of 50% greater cost for 10% longer life -- might not be too far off the mark (though I myself would guess that it’s probably more like 50% greater cost for a 20-25% longer life), ... BUT … with a very important caveat ... that being that such numbers (whether Darell’s 10% longer life or my 20-25% longer life) are applicable to 90% of the country, with the exception, the other 10% of the country, being the hottest climates like Phoenix and South Florida, where a very different set of numbers and relationship applies. In the hottest climates, places like Phoenix and South Florida, the numbers look something more like … a 50% greater cost for somewhere between a 2X and 3X longer life. You really have to get into all the science and empirical studies and data on lithium battery life as a function of long-term ambient temperature exposure (plus, additionally, very importantly, the effects of solar loading), that I referred to above, in order to fully understand and have an appreciation for this. It also helps if you have had your own personal experience and exposure, as I have had, with battery life, performance, degradation, and ageing characteristics over a long term in a hot climate.

The salient point and operative principle here is that lithium battery life follows an exponential Arrhenius relationship with respect to temperature, where just to try to greatly simplify the explanation … battery life basically doubles for roughly about every 25 degrees F reduction in temperature (to simplify again, let’s call it long-term average ambient exposure, though that ignores the important roles and factors that both temperature variation and solar loading play). So, here pulling my own numbers out of my hat, let’s say that at 100F lithium battery life is 3 years; then at 75F it’s 6 years, and at 50F it’s 12 years. Those probably aren’t too far off the mark, though there is some differentiation for the various different cathodic subchemistries (e.g. LiCoO2, LiFePO4, LiNi.33Co.33Mn.33O2, and the LiMn2O4 chemistry, that both GM and Nissan are using in the Volt and Leaf, being the most heat sensitive and having the shortest life at higher ambients).

If you understand what I’ve just explained, then you can see and understand that it is the combination of: a) the high ambients in hot climates like Phoenix and South Florida, b) the exponential nature of this Arrhenius function relating lithium battery life to temperature (where battery life roughly doubles for about every 25 degrees F reduction in temperature), and c) the high current cost of lithium batteries [$625/kWh for the Volt ($10,000/16kWh) and $750/kWh for the Leaf ($18,000/24kWh)], … that makes a liquid-cooled, water-chilled, active thermal management system economically advantageous and viable ***FOR AN EV THAT WILL SPEND ITS LIFE IN A HOT CLIMATE***.

However, this is not necessarily going to be the case for the other 90% of the country with more temperate climates, to varying degrees, where -- as Darell suggests with his “out-of-his-hat” guesstimate numbers -- a liquid-cooled, water-chilled, active thermal management system might not present such a compelling value proposition and be entirely economically viable.

The problem is that automakers don’t have the luxury of being able to micro-design and custom-tailor their EVs for each climate, offering a different version, with a different type, level, and scale of thermal management system, depending on the particular climate. Nor do car owners always stay in the same location. People move from one place to another, like from a temperate climate to a hot climate, and take their cars with them. Automakers have to design their EVs to work in ALL climates. What this means is that if an automaker is really going to do it properly, they have to design the EV to operate in and withstand the harshest, hottest climates, like Phoenix and South Florida. We can call that the 10% climate outlier tail. So the automaker that does it properly has got to design to specs for that 10% tail, unfortunately, which then of course drives up the cost, … which is one reason why the Volt costs $8k more than the Leaf. (And yes, it is somewhat of a case of “the tail wagging the dog”.)

… Whereas, on the other hand, other automakers will take a very different path, where in the aggressive pursuit of their ambitious goals to establish an early market-share lead, they succumb to the temptations and imperatives of cost and time-to-market pressures, making those their top priorities, at the expense of engineering, by making engineering compromises, shortcuts, and trade-offs in the process, … by, for instance, making a deliberate, calculated sacrifice of that aforementioned 10% climate outlier tail, in the interests of expediency and cost savings. To paraphrase Carlos Ghosn, there are a few notable, and quite telling, quotes in the last year where he has basically said, in so many words … “shoot the engineers and put the marketing guys in charge”.

· Charles Whalen (not verified) · 4 years ago

Further to my post above, here are a couple quotes that touch upon and reflect the more detailed explanation and scientific references I gave above …

GM-Volt.com: Achieving a ten year 150,000 mile goal is something it sounds like you’re very confident in now.

Bob Lutz: "Without committing to it being ten year or 150,000 warranty basically we are very very confident in the capability and the life of this battery in all but the hottest climates. So it could be that in certain very hot climates where people leave this thing in a baking supermarket parking lot all day, these lithium ion batteries, if they get much over 95 or 100 degrees Fahrenheit, they quickly start losing life. So we may have to adjust warrantees, but we really haven’t decided how to do that yet."

GM’s Volt executive Tony Posawatz explained why separate battery HVAC is so important in electric cars.

“Thermal management has bookend issues to manage: minimized power at low temperatures and life reduction at high exposure to higher temperatures,” he told Wired. “If you want to replace your battery every four to five years and someone is willing to pay for [a replacement battery], either the customer or the manufacturer, a modest or minimal HVAC system may work.”

Excerpted from:

http://gm-volt.com/2010/05/03/bob-lutz-on-chevy-volt-pricing/

and

http://gm-volt.com/2010/01/28/nissan-taking-shortcut-on-leaf-battery-no-...

You might also want to check out the following article:

www.wired.com/autopia/2010/01/nissan-leaf-2/

· · 4 years ago

Nice comments Charles. Do you think a liquid cooled, complex thermal management system could/should be offered as an option, albeit an expensive one?
Kind of like how they offer cold weather packages to ICE cars now with engine block warmers, larger batteries, wiper defrosters, etc.

I know it may only be necessary for 10% or so of the population, but that's still a lot of potential EV owners.

· · 4 years ago

Thanks, Charles.

When I said we won't know how long the batteries last, I didn't mean the chemistry - I meant the specific application in the Nissan Leaf. That we can't really learn by studying documents of battery performance.

Tom: Compelling idea! Those in temperate climates wouldn't need the extra expense of more rubust cooling, and those who live in very hot or cold climes wouuld surely benefit from better thermal management. Just like people pay for cold weather packages (as you point out) and 4WD etc.

· Jesse Spears (not verified) · 4 years ago

I'm hoping that the EV panel of the higher level Leaf package will be used to aid in cooling the batteries while parked in the sun.

I can't imagine what else it could really be good for. It doesn't look like it would provide enough power to actually charge the batteries, or even run the AC. But it might have enough power to run a fan that just pulls air through the battery compartment to keep it close to ambient air temperature (which is easily 20-30 degrees cooler than the inside of the car on a hot sunny day in Austin in August). That might not save them in a place like Phoenix, but I bet it it would help the rest of the country during the summer.

Likewise, during the winter, it could provide a small amount of heat to the batteries.

I have no idea if that's what they're actually doing, but it sure seems like a good idea to me.

· · 4 years ago

If you're in the Desert Southwest and parked in an okay area, I suppose it wouldn't hurt to leave the windows cracked open a bit...

Where we live in the California mountains, heat isn't really a problem. However, now I'm wondering if we should be concerned about the batteries overheating while making the 16 mile, 5000 foot climb to our town, at 40-50 mph. I'm sorry to be mentioning our mountain climb ad nauseam, but I think these questions are worth asking, and will apply to others as well.

· · 4 years ago

Abasile, I really wouldn't worry about overheating the batteries unless you are doing this ascent in really hot temperatures. I would suspect you will have slightly less range because of the climb, but overheating will not be a problem.
I have done a lot of stress tests with my car like constant 85-90mph for 15-20 miles and the batteries do not overheat. I really only have a problem when it's hotter than 93 degrees outside and I drive at highway speeds, that's when the pack gets above 106 degrees.

· Charles Whalen (not verified) · 4 years ago

Responding again to Darell (following up on my previous two posts above) …

> When I said we won't know how long the batteries last,
> I didn't mean the chemistry - I meant the specific
> application in the Nissan Leaf. That we can't really learn
> by studying documents of battery performance.

Well, if it’s in-vehicle/on-road lithium battery life experience that you’re looking for, and Nissan’s specifically, you don’t have to wait 5 years to find that out. The 15-year on-road experience with Nissan’s lithium-powered EVs in Southern California has seen such high rates of capacity decay and degradation that their lithium battery packs have typically needed to be replaced every couple years. One would hope and presume that this latest iteration of Nissan’s LiMn2O4 batteries that are going into the Leaf is greatly improved over earlier versions, and I’m confident that that is indeed the case.

A good indication of how long the Leaf’s battery pack will last in a hot climate is what Nissan has been telling fleet managers in hot climates, and that is to expect a 4 to 5 year life. This is why fleet managers -- as well as many EV-savvy/knowledgeable individuals -- in hot climates are planning to take the Leaf on a 3-year lease, rather than purchase the car, and then return it to Nissan at the end of the 3-year lease. (It is for this same reason that I myself am planning to lease, rather than purchase, the Leaf.) In fact, Nissan is actively encouraging this -- for customers in hot climates to take the Leaf on a 3-year lease rather than purchase -- in order to relieve and take that battery degradation problem out of the customer’s hands and let Nissan assume that risk and deal with that problem.

Although you (and the public in general) may have some uncertainty in your own mind (because you don’t have any familiarity or experience with this issue) about the necessity of a robust, advanced, liquid-cooled active thermal management for the current generation of lithium-manganese (which, out of all the various lithium cathodic subchemistries, is the most heat sensitive and has the highest and fastest rate of capacity decay and degradation at higher ambients) batteries in order to achieve acceptable longevity in a hot climate, there is no doubt or uncertainty about the necessity of that among battery engineers in the battery and auto industries. To the contrary, there’s a strong consensus on that point, including even among Nissan’s own engineers, who argued for just such a liquid-cooled thermal management system but were overruled by senior management on grounds primarily of cost and secondarily because senior management and the marketing folks didn’t want to give up the third (middle) seat in the back, which would have had to have been given up and sacrificed for a taller battery pack assembly in order to accommodate the liquid-cooling TMS (as is the case in the Volt).

Carlos Ghosn has been refreshingly candid in admitting that the Leaf’s design decisions have been dictated by the bean-counters’ spreadsheets, as well as by the marketing folks, while relegating the engineers to the back seat (literally as well as figuratively). It’s been very much a case of accounting and marketing trumping engineering. Nissan has led with accounting and marketing on the Leaf, while GM has led with engineering on the Volt.

Nissan North America CEO Carlos Tavares has been similarly refreshing in his own candor in admitting that Nissan’s 8-year battery warranty decision was driven entirely by marketing considerations and public perception and was not based on engineering, in fact was completely divorced from engineering. GM’s announcement of their 8-year battery warranty for the Volt forced Nissan’s hand into matching that warranty several days later, due to competitive pressures, because Nissan simply could not afford to publicly capitulate to GM on this point and so openly expose their engineering weaknesses on the Leaf relative to the Volt.

In making the difficult (and painful) decision to match GM’s 8-year battery warranty, Nissan management understood and knew full well that this will result in them taking some losses 4-5 years down the road in having to replace battery packs under warranty in hot climates. For one thing, that’s why they’re encouraging people in hot climates to take the 3-year lease rather than purchasing the car. But more fundamentally, this whole thing was basically just a cold, hard-nosed, bottom-line, calculated business decision, pure and simple, … similar to other such types of business decisions that other companies in the automotive and other consumer products industries make all the time. This goes back to Darell’s “out-of-his-hat” speculative numbers, that I followed up and elaborated on in my first post above. Nissan management has calculated that, in the aggregate, it will cost them less to replace battery packs under warranty after 4-5 years in the 10% climate outlier tail (for those few hot-climate customers who don’t take the hint to go for the 3-year lease rather than purchase) than it would have cost them to design, engineer, and manufacture an advanced, robust, liquid-cooled thermal management system for each and every car for the entire country.

But lately Nissan senior management has begun to realize that they’re starting to suffer a public perception problem of the type that they had hoped to avoid (and be able to slide by, through the launch and first year or two, sweeping all of this under the rug and keeping it under wraps) but that has become unavoidable as all of this is starting to seep out into the public domain, getting revealed and exposed, with greater public discussion of this whole issue. Senior management is now starting to get worried about the possibility of a backlash and that their design and development decisions to let accounting and marketing trump engineering are going to come back to haunt them, just as Nissan’s engineers had warned would happen. So now we’re seeing Nissan senior management starting to backtrack on their previous party-line position (for public consumption) with respect to the whole thermal management system issue and are doing a reversal where they are now saying that they’re planning an advanced liquid-cooled TMS for the next model upgrade of the Leaf.

The problem with this, however, is that this will require a fairly substantial redesign and retooling of the vehicle platform, as they gave up that possibility when they committed to the current vehicle design of having sacrificed a robust thermal management system in favor of a third (middle) seat in the back. So it’s going to be back to the old drawing board for the next model version of the car.

… Which brings me, finally, to Tom’s question to me:

> Nice comments Charles. Do you think a liquid cooled, complex
> thermal management system could/should be offered as an
> option, albeit an expensive one?
> Kind of like how they offer cold weather packages to ICE
> cars now with engine block warmers, larger batteries, wiper
> defrosters, etc.
>
> I know it may only be necessary for 10% or so of the population,
> but that’s still a lot of potential EV owners.

I would echo Darell’s comments on that being a compelling idea that you raise there, Tom. In addition to what Darell said, I would just add, by way of example … take a look at the production plans for the Tesla Model S, wherein Tesla is planning to offer three battery pack options of different sizes and capacities, with 160, 230, and 300 mile ranges, respectively, for the same car. So yeah, I do think something like what you suggested could be done and find that an intriguing possibility.

I should say, however, looking out 5-10 years, towards 4th and 5th generation EVs [with the current generation of Roadster, Volt, and Leaf being 2nd generation EVs, (at least from the perspective of those of us who have been driving 1st generation EVs for a number of years now), and vehicle generation development cycles getting shorter, being compressed toward 3 years, instead of the traditional 4-5 years], that I don’t think sophisticated thermal management systems will ultimately be the solution to this problem. They are really just a short-term, somewhat kludgey (and very expensive) fix for the current (2nd) and next (3rd) generation vehicles, to get us through the next 5-6 years. We’re going to have real problems, in terms of the economic viability of EVs and their adoption and penetration rates, as intended mass-market vehicles, if we’re still using these expensive, complex, sophisticated, liquid-cooled, water-chilled thermal management systems (like that in the first generation of the Volt) to solve this hot climate battery life problem, as we get into the second half of this decade and approaching 2020. But I don’t expect that to be the case.

No, the ultimate answer to this problem is to be found in the electrochemistry, with an electrochemical solution, where the cathode, anode, and electrolyte are specifically designed, developed, and optimized for life and operation in a hot climate. Then the OEM doesn’t really have to worry so much about the thermal management system and can just go with a simple ambient forced-air type system that only runs during discharge and charge. For example, on the cathode side, carbon-coated nano-LiMnPO4 and carbon-coated nano-LiMn.8Fe.2PO4 both show excellent morphological and structural stability in solution at high temperature (60 degrees C) over time. (The specific mechanism of internal resistance increase at elevated temperatures, for current generation lithium battery chemistries, is primarily due to film growth on the particle surfaces, both at the cathode and at the anode, with the amount of such film growth being a function primarily of the level of heat exposure over time.) Such promising electrochemical solutions to the hot climate battery life problem have been well known and understood for several years now. It’s just a matter of scaling them up, working out licensing issues, and commercializing them. I expect to see such electrochemistry-based approaches and solutions employed in vehicles as we get into the second half of this decade, certainly as we approach 2020. We will definitely need them in order commercialize EVs for the mass market, if they are ever to become economically viable beyond the initial 5% early-adopter segment. I’m very hopeful and optimistic that that will indeed be the case.

· · 4 years ago

I know I'm late on this comment thread, but what exactly are "extreme" temperatures for an EV battery pack?

On the Colorado Front Range, we see up to 5 days a year of 100+ temps and probably another 10 to 14 days a year of below zero temps. However, mostly what we see is 80s and 90s for highs in the summer and lows regularly in the teens and 20s in the winter.

From what I'm picking up here, it seems like Denver is a liquid cooling system climate -- but maybe I'm missing something?

· TechExplorer (not verified) · 4 years ago

I'm a Fan of the Nissan Leaf and others,I drive a 2010 Ford Fusion Hybrid.I have been looking @ the Leaf for purchase,After reading this forum and others about Thermal management issues with the Leaf and concerns,I now have to take a breath and maybe rethink ? I live in a Hot Climate along the Gulf Coast,the other day was 106 F. with heat index around 116 F. Summer months are hot ,humid etc.I would be one to purchase not lease a Vehicle of this nature,I have Concerns,but steel look forward to such vehicles !!

Thanks for all the Great Info. !

· · 4 years ago

TechExplorer: The truth is, none of us here really know how well the LEAF will function in temperature extremes. They are using a battery chemistry that has not been previously available so there is no data that is public for us to review. In another thread, I offered my experiences with the MINI-E that uses a different battery type and chemistry. The MINI-E's battery and passive heating/cooling system are inadequate for extreme conditions, but it is a prototype vehicle, not offered for sale. I would suggest that if you live in an area that is as hot as you explain then it might be prudent to wait until you get some feedback from LEAF owners about how well the car performs in the heat. It may very well work fine is all temperatures, just wait a few months more before you buy one, that's all.

· · 4 years ago

Thanks,I planned on waiting.I also been looking @ the Volt,interesting ! $$ is a great Concern ?
My Ford Fusion Hybrid uses Passive Cooling for Battery Pack,uses Cabin Air , no Problems,so Far Great Car ! Better milage than EPA rating on AVG. Just wish my State was forward Thinking on incentives ! AL.,not to get off the Subject .

· Charles Whalen (not verified) · 4 years ago

Further to my posts above, especially the one with the quotes from Bob Lutz and Tony Posawatz, here’s yet another interesting and revealing quote, this one from Volt Chief Engineer Andrew Farah, pertinent to this issue:

One disappointment is that the Volt and other Lithium-ion battery-powered electric vehicles may not be viable in hotter climates, such as some states in the American Southwest. Despite the fact that Volts will be sold in these states, performance may be significantly undermined due to the heat. Volt Chief Engineer Andrew Farah describes, “The Volt may not be right for everyone. If you live in the Southwest, depending on how you use your car, the Volt might not be right for you.”

Excerpted from:

http://www.dailytech.com/Chevy+Volt+Cant+Handle+Hot+Southwest+but+Otherw...

· Anonymous (not verified) · 3 years ago

Good discussion!

A few other things to consider here are thermal mass, parallel strings, and temperature's effects on DC resistance.

The batteries are very massive. I work for Argonne and can vouch for the impact this has on Joule heating. Some of the lithium chemistries will see a 12-18C increase discharged at their full rate until empty with no cooling starting from say a 22C ambient temp.

Since EV batteries require significant capacity, they typically have multiple parallel strings which divides the current through each string accordingly further reducing joule heating.

Lastly many of these chemistries see a reduction in resistance as they warm up with again further reduces joule heating.

As far as ambient heating is concerned any of them will warm up to the ambient. There are some active cooling devices working on the same priciples as your AC system (and a few other methods) but they do add cost and typically consume more energy (reducing range). They also add mass (reducing acceleration and range).

My guess is Nissan would rather have most of the customers enjoy improved range and performance and honor the warranties in those select warmer areas as opposed to the trade off of adding the cooling systems.

Elon likely just doesn't know what he's talking about.

· · 3 years ago

Thanks for the comments Charles.
Does ambient temperature affect Li-ion shelf life or just cycles ?

· green (not verified) · 2 years ago

I support Tesla all the way, they have been in front of the curve since 2007 and continue to make amazing improvements.
My question is what happens to these batteries when they need to be replaced, are they recyclable or are we creating yet another toxic element that will sit in our landfills for the next 5000 years?

· · 2 years ago

> are they recyclable or are we creating yet another toxic element that will sit in our landfills for the next 5000 years?

They're recyclable, and much less toxic than you are assuming. These are NOT NiMH or NiCAD. Battery recycling really is one of the recycling success stories of our time. Beyond that, please don't compare scary battery replacements with rainbows and the laughter of children. It must be compared to all the fossil fuels that we "recycle" through gas cars today. Every day you start up a gas car, you are making toxic waste. EVs don't burn gas or use engine oil. And the solar-charged batteries in my Rav4EV have been running the car for over nine years now. No oil changes. No tuneups. No fossil fuels. Eventually the batteries WILL need to be recycled. But just look what they've avoided in the meantime.

· · 2 years ago

Green: First, yes they are recyclable. However they won't be recycled immediately after they are replaced from an EV. It's generally accepted that when an EV battery degrades to below 80% of it's capacity, replacement is considered. However the battery at 80% is still very valuable and will have a 2nd life use. Utilities for instance are developing plans to buy them from the car manufacturers to use for load balancing. Also, there are companies that are looking into buying them, repackaging them and selling them to homeowners as an energy storage device for power outages. You could have 30kwh of electricity stored in your basement at all times, just in case there is a power outage. This could run your house for a few days if you use it wisely. The batteries would last a long time if used in this fashion. This is just a few possible 2nd life uses.
They will eventually be recycled, but probably not for a decade or so AFTER they are replaced from the car.

· · 2 years ago

Curious - someone brought this 1 year old thread back alive, soon after FFE launched. There was also someone lese in the FFE thread said FFE should be compared to Leaf SL - and not SV (without giving any reason). The same thing was repeated by Ford marketing in the interview.

· · 2 years ago

@Green,
Here's Tesla's response to your concern:
http://www.teslamotors.com/blog/teslas-closed-loop-battery-recycling-pro...
But darelldd is also correct in pointing out how this is so minimal compared with the alternative - burning gasoline. Tom is correct in pointing out that recycling probably won't happen until every watt-hour is squeezed out of the battery - Reduce, Reuse, Recycle

· Anonymous (not verified) · 2 years ago

Interesting how it's the two 'complex' actively liquid cooled battery EV cars (i.e. Volt and Karma) that are being recalled for a fire risk, as it sounds like the battery coolant can leak onto the battery circuit boards and start a fire. I'll bet the simplistic, air-cooled battery LEAF will never have this particular problem -- sometimes simple IS better.

· Howard (not verified) · 1 year ago

The LEAF uses lithium NOT NiMH and NiMH does not need anywhere near then same BMS as the EV95 had a temperature tolerance of -30c to +70c no lithium has that.

· Sasparilla (not verified) · 1 year ago

Interesting how the Leaf's cheaper / simpler passively cooled pack has ended up having problems in the Southwest where it looks like the packs are being cooked and loosing capacity much faster Nissan was telling folks it would happen.

Must was right on the liquid cooling point - and that is probably why everyone else is doing that.

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  2. A Quick Guide to Plug-in Hybrids
    Some plug-in cars have back-up engines to extend driving range.
  3. Electric Cars Pros and Cons
    EVs are a great solution for most people. But not everybody.
  4. Eight Rules of Electric Vehicle Charging Etiquette
    Thou shalt charge only when necessary. And other rules to live by.
  5. Seven Things To Know About Buying a Plug-In Car
    A few simple tips before you visit the dealership.
  6. Eight Factors Determining Total Cost of Ownership of an Electric Car
    EVs get bad rap as expensive. Until you look at TCO.
  7. Federal and Local Incentives for Plug-in Hybrids and Electric Cars
    Take advantage of credits and rebates to reduce EV costs.
  8. Guide to Buying First Home EV Charger
    You'll want a home charger. Here's how to buy the right one.
  9. Electric Car Utility Rate Plans: Top Five Rules
    With the right utility plan, electric fuel can be dirt cheap.
  10. The Ultimate Guide to Electric Car Charging Networks
    If you plan to charge in public, you'll want to sign up for charging network membership (or two).