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Battery degradation is an interesting issue and it'd certainly help if the warranties were extended well beyond other powertrains. They seem to generally follow a similar curve of a slightly larger initial dip in the first few years and then a very slow dip for much of the years after.
I think this is why some automakers like Porsche with its Taycan voluntarily lower their marketed range for the vehicle so that they don't need to ever come close to having to replace on warranty and why the Taycan is rated in the lower 200s for range that people are pretty easily seeing higher 200s or low 300s for range in their actual experience. This is also something that better battery management systems and a larger battery pack obviously help with. There are multiple factors that go into battery degradation, but generally it hasn't been too severe for battery electric vehicles save for the Leaf which starts with a fairly small battery pack and no active thermal management systems which is quite different from most modern EVs. Obviously, you can still get what is more of a lemon relative to the average (as can be seen with a few of the dots in the chart above though you also have some pretty lucky people who seem to have vehicles that do much better than average as well), but that's also true of vehicles in general.
Where the rationale behind the tipping point of cheaper battery costs at or below $100 per kWh comes in is that with the lower cost comes the ability to have a larger battery pack for any given price bracket for the vehicle. A larger battery pack with greater capacity and hence range affects two of the main attributes of battery degradation pretty directly.
One is that degradation ties closely with the number of duty cycles (essentially the number of times effectively gets charged and depleted) and so if a single duty cycle for one battery pack gets you 250 miles of range and a single duty cycle for another battery pack gets you 100 miles of range, then the latter will go through 2.5x the duty cycles for any set number of miles. If you use 250,000 miles for an example, then 250 miles of range is 1,000 duty cycles for the 250 mile battery pack, but 100 miles of range goes through 2,500 duty cycles.
The second way it addresses this is that a larger battery pack means that keeping the battery pack within 25% to 75% state of charge most of the time is a lot easier to do since that still yields a pretty high usable amount of range for most driving habits once you get to what we consider long range today. Note, those 25% to 75% numbers aren't generally the state of charge your EV shows you in its display. All automakers already build this in by default to some extent where the range they show are based on what they determine to be usable capacity whereas the battery pack capacity in truth is actually somewhat larger so as to keep a buffer away from going completely depleted or completely charged so your 0% and 100% displayed are generally not actually full depleted or full charged. This will continue to be the case, but the optimal usable range as battery prices come down and you see larger and larger capacity packs means that having a well usable amount of charge for most people's uses while keeping it within that optimal middle becomes more and more common for most use cases.
Some of you have probably come across something along the lines of a "million mile" battery pack--there are vehicles with battery packs that are near that point supposedly and all of them are large capacity battery packs. When that threshold comes, which seems likely to come soon though not guaranteed to be inevitable, it will probably be with what we consider pretty large capacity battery packs today in the higher two digits to lower three digit kWh range.
What I think the most disappointing thing though is that the replacement battery supplier network for when things do go pear-shaped hasn't sprouted up as strongly. That makes sense in the context of modern EVs not having been around very long and the number of EVs solid intotal to support such a network haven't gone up much, but it would certainly give people more confidence if there was more forethought put in and communicated for there being a clear pathway to taking advantage of battery improvements in the case of a vehicle reaching a point where a replacement of the battery of a vehicle that is otherwise very intact and operable. After all, if things were built with an eye towards the future and there were more open control systems and a more standardized pack or module that a third-party could produce, then a first generation Nissan Leaf supposedly could have a very cheap battery swapped in with more capacity, more range and lighter weight at a pretty low cost which would be great. We'll have to see how long it'll take for that kind of thing to happen, but I would suspect that a combination of a larger market and potentially the EU's seeming turn towards legislating greater hardware openness and right to repair laws will improve things.
Last edited by OyCrumbler; 03-19-2021 at 05:10 PM..
I don't think overall degradation is really an issue. The bigger problem is if you are unlucky enough to to get a random bad cell or two. I don't think anyone knows why one cell out of a whole pack will die.
As you can see in this example, one bad cell out of 96 reduced the range drastically, and was probably close to disabling the car. For whatever reason, it didn't happen until 60k miles. I am curious what the out of pocket replacement cost is for one module in a Bolt that is out of warranty.
I don't think overall degradation is really an issue. The bigger problem is if you are unlucky enough to to get a random bad cell or two. I don't think anyone knows why one cell out of a whole pack will die.
As you can see in this example, one bad cell out of 96 reduced the range drastically, and was probably close to disabling the car. For whatever reason, it didn't happen until 60k miles. I am curious what the out of pocket replacement cost is for one module in a Bolt that is out of warranty.
Well, do you know about wiring things in series versus parallel? Supposedly, one would make a battery pack so that a bad cell or multiple bad cells would not cripple the entire thing and it would be made with redundancies such that some bad cells does not spoil the barrel, though it's good to have the ability to know you have a bad cell and to be able to go get it fixed even if the vehicle still functions fine overall (which isn't the case with that Bolt). It is in the manufacturer's best interest to be able to identify and swap bad cells though, because from that thread, it looks like the person is getting a new pack which is sort of a win for him, but it would seem like a generally uneconomical process for the manufacturer. The only thing I can think of that makes that sensible is if the battery swap is just to make it go faster and keep a happy customer and then GM has the old pack to have in a slower, but controlled setting fix it up to be usable as a replacement battery in the future or has a real recycling or reuse process already down pat. However, I would've hoped that there was an eye towards maintenance that makes a bad cell swap easy and quick to do at the dealership or by a third-party. Of course, then how would that money get made if so much of the other maintenance bits of an ICE vehicle are taken away? I guess that's a bit cynical.
This is also why I'm a bit iffy on this structural battery pack that Tesla is talking about. The way it makes things more efficient and cheaper and all that makes sense. Great. However, I wonder about how that fares with maintenance and especially with generally less expensive, third-party maintenance. I'd feel better about it if this was a very long warranty or there was some kind of explicit pathway for replacement for that.
Regardless, a larger battery pack can ostensibly depending on how it's designed, also better accommodate a bad cell in addition to overall degradation.
Last edited by OyCrumbler; 03-19-2021 at 07:25 PM..
If you are interested in a much more informative article than the one in the original post, I highly recommend giving this a read.
The author, John Paul MacDuffie, is Professor of Management at the Wharton School and Director of the Program on Vehicle and Mobility Innovation (PVMI) at the Mack Institute for Innovation Management. His research, primarily on the global automotive industry, has examined the impact of human resource systems and work organization on economic performance.
I took a course from MacDuffie a while ago and he is not prone to emotional prognostications. He is recognized as a leader in global research on the automotive industry and is cited in a great deal of the academic work in the space. It was fun trying to write a paper on the auto industry and finding your professor’s name come up in almost every peer reviewed research paper you wanted to use. No pressure to get it right!
He does a good job pointing out the challenges, but expects that EVs will overtake ICE sales within 20 years.
Here are a few pieces I found particularly interesting, but suggest reading the entire article.
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....we think that within two decades a majority of new automobiles sold in the U.S. will be electric.
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This system will require substantial changes in how we regulate and operate the grid, including metering, pricing, and funding key modernization projects such as expanded grid-scale electricity storage. It will rely on close public-private cooperation on everything from advances in battery design to ensuring that fast-charging stations one day become ubiquitous. And this vision will face tremendous inertia and resistance because it is fundamentally at odds with the regulated monopoly mindset, giant power plants, and fossil fuel reliance of current grid operators.
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With batteries critical to growth in EV sales, the technology faces the familiar challenges of cost, range, and recharging time. The first truth of battery development is that unlike the exponential growth in the power and speed of computer chips, known as “Moore’s Law,” there’s no reason to expect exponential (rather than linear) improvements in key battery performance metrics. Any battery “breakthrough” you read about will provide only incremental gains, in relative terms, compared to the silicon chip advances that fueled the IT/digital innovation of the past few decades.
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Faster recharging times are, therefore, now coming into sharper focus. (Toyota, notably slow in providing battery EVs due to its earlier strategic bets on hybrid drive trains (i.e. Prius) and fuel cell EVs, is now promising a solid-state battery EV — with a range of 300-plus miles and 10-minute recharging time — in prototype this year.)
If you are interested in a much more informative article than the one in the original post, I highly recommend giving this a read.
The article is a good high-level summary of where we are. Unfortunately it got off to a bad start by citing the Texas blackouts as evidence our national grid is not ready for EV's. The Texas grid problems are absolutely unique to Texas and have nothing to do with EV readiness. Hardening the grid to withstand extreme weather is separate from upgrading capacity and transmission needed for full EV adoption.
The article is a good high-level summary of where we are. Unfortunately it got off to a bad start by citing the Texas blackouts as evidence our national grid is not ready for EV's. The Texas grid problems are absolutely unique to Texas and have nothing to do with EV readiness. Hardening the grid to withstand extreme weather is separate from upgrading capacity and transmission needed for full EV adoption.
You're right. And even though some people can legitimately point out that the grid is not ready today, for 100% EV adoption, that point, while true, is really a red herring. Full adoption will come across decades, and over that time, utilities will add capacity, just like they already routinely do, to accommodate additional demand. There is no insurmountable barrier.
I've cross shopped USAA with Progressive and Geico and their rates pretty much are the same (which is why I haven't changed No reason to if there's no real benefit). I had a custom Volt before the Bolt and it was the same.
WRONG about USAA rates being the same for Geico and Progressive. It's well known the USAA is 25 to 50 percent cheaper than even the cheapest insurance, and both Geico and Progressive are A rated insurers. So I'm pretty sure you are outright lying here.
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And no it's not a fact that they cost that much more to insure than equivalent gas vehicles. Otherwise I'd be paying more regardless of carrier. Look at the General for your own rates. Try the Progressive match feature. BTW, you're saying EVs cost more, but the only one you want and checked on is the more expensive Tesla. Did you perchance check and see how much a BMW M340i costs you to insure? Or an Audi S4 or RS4? Because those are it's competition, not a damn Kia.
Like I said, I only want the Tesla, and it's for the self drive feature mostly. I could care less about it being an electric vehicle or not. I just want to get off the grid, and for now, gas is still the best way to go for both getting off the grid, reliability and overall costs.
And I won't drive no damn Nazi car, so German cars can go take a hike!
WRONG about USAA rates being the same for Geico and Progressive. It's well known the USAA is 25 to 50 percent cheaper than even the cheapest insurance, and both Geico and Progressive are A rated insurers. So I'm pretty sure you are outright lying here.
Well known by whom? My wife had USAA and I can assure you it was nowhere near 25% cheaper than CSAA/AAA.
Has anyone come across a reliable report for 2020 US new vehicles sales with a breakdown of both full battery-electric market share and plug-in hybrid market share?
I see a 1.8% BEV new vehicle market share here, but nothing about how plug-in hybrid electric vehicle market share. I know that the big new entrant for PHEVs is the very solid RAV4 Prime, but I believe Toyota had stated they were only going to send 5K units to the US for the first year before increasing to 20K for the next year so couldn't have been that consequential.
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