Here’s How Electric Cars Will Cause the Next Oil Crisis

[ERD50]

I'll try. Am sure there is a good site out there who did it thoroughly as well. ....

I did find a decent calculator (and a few poor ones).

Electric Car Calculator

[ Hit "CALCULATE", not your 'enter/return' key - that takes you to ads! ]

Wow, I really thought EVs would result in more savings.

I left miles at 12,000 (supposed annual average in US?).

I 'faked' a $35,000 Model 3, and assumed the tax credits have run out (selected the Leaf, and then changed the price and credit). Then chose a Prius V to compare (larger, and 'only' 44 mpg versus 50 for the smaller Prius). I used their estimated maintenance cost (~ $371 for Leaf ~ $600 Prius)

I also upped gas prices to $3.00 from their ~ $2.00 (I really doubt gas will stay this low), and changed $/kWh down to $0.11 (closer to my marginal rate) from their ~$0.13. All those are advantages to the EV.

And.......

Years to break even: 12 years 9 months



Even a plain old vanilla Honda CR-V 4WD (21/27 mpg) is 8.5 years.

edit/add: And as is typical, they don't appear to take into opportunity cost of the > $10,000 purchase price delta to the CR-V. Let's see, losing your 3.5% WR estimate - another $350/year. So... subtract that from the CR-V maint costs, and you are at 11 years 8 months.


-ERD50

 

[Totoro]

Why the facepalm?

Cars last on average I believe for 20 years. So if there is a cross-over point after 12 years that should translate in a higher residual value.

And we were talking high mileage cars, 12k is average in the US. 30k should be the high use case. Shortens it a bit more.

Also, the US combines moderate electricity prices with lowish gas prices, and road taxes aren't tied to tailpipe emissions (as far as I know).

We're not at "EV, unless" vs. "Hybrid/Gas, unless", but it's getting closer fast.

 

[Gone4Good]

Years to break even: 12 years 9 months

Am I reading your post correctly? You're comparing an entry level luxury car to a Prius and are surprised to find that the luxury car takes so long to cost less?

If someone told me I could get an Audi A4 and it would cost me less to own over it's lifetime than a $26K MSRP Honda I'd think that was a pretty amazing discovery.

I don't think people are paying $35K+ for a car because they think it will save them money. You pay that kind of coin for status, the appearance of quality, and gee-wiz features. But if you still want to run a break-even, comp against it's actual competition: BMW, Audi, Mercedes.

And like all new tech, when (if?) production ramps up prices will fall. Not necessarily on the Model 3 which will probably stay at that price point, but for the next model down.

I still remember the first ever flatscreen TV I saw in a store retailed for $20K. I think it had a 36 inch screen.

 

[Rustic23]

Erd50/G4G's comments, are thought provoking. However, I don't see the EV as anything but a niche market if it has to depend on power plants. The problems with generating enough electricity to swap say 50/50 EV/Gas seems impossible. What is the costs, and the environmental impact of producing the batteries? Can lithium batteries be recycled efficiently? A break in fuel cell prices would, IMHO, change everything.

 

[ERD50]

Am I reading your post correctly? You're comparing an entry level luxury car to a Prius and are surprised to find that the luxury car takes so long to cost less? ...

You have a point of course, but it depends where your focus is. For my example, the focus was overall economics. Since we don't have any other $35,000 or lower EVs with 200 miles range, it becomes the comparison to other transportation that would be very economical. I chose the Prius V for one case - the largest and lowest MPG model Prius - if I were really trying to put my thumb on the scale, I would have compared to the standard Prius, and I would not have adjusted their default gas & kWh prices to favor the EV. Then I compared to a popular vehicle that gets the job done for us, just as another data point.

No, they are not apples-to-apples, but it is what we have. And it won't be apples-to-apples until I could use that EV to drop my kid off at a rural college 250 miles away, then turn around and drive back the same day without any more delay than an ICE fill up.

Just like the first Tesla models were able to 'bury' the battery cost in performance, the Model 3 (to a lesser extent) is 'burying' the cost of batteries in a little luxury. And since it hasn't been reviewed yet, it's hard to say what a real comparison is.

If you can point out a 5 passenger EV with 200 mile range that sells for less and compares feature-wise with a Prius V, I'll run that comparison. That's my point - there is a premium for those batteries, and it affects the comparisons at the lower end. Until batteries/motor are on par with ICE/tank, something has to give. As they get closer to par, the payback for miles driven will be quicker. And we still need to see if battery replacements are going to be common at 100,000 or 120,000 miles - engines are lasting significantly longer than that these days.

-ERD50

 

[NW-Bound]

The longevity of the expensive battery is the elephant in the room. Nowadays, it is common to see combustion-engine cars with 150K miles or higher with no needed major repairs.

 

[Gone4Good]

there is a premium for those batteries, and it affects the comparisons at the lower end. Until batteries/motor are on par with ICE/tank, something has to give.

I'm completely agnostic on all of this but I don't think we can even really hazard a guess until we see what economies of scale do for us. Right now building an ICE vehicle is about as cost efficient as it's ever going to get. Building an EV is still heading down the cost curve.

So comparing the cost of today's EVs at minuscule production volumes against ICE vehicles at scale doesn't really tell us much about the economics of the various technologies unless we assume EVs stay a niche product.

But will they?

Right now we have a luxury EV that's gone from zero to category leading sales volumes in a couple of years.

We have an entry-level EV in the works that people are excited enough about to part with $1,000 just to get on a waiting list to own one.

That doesn't mean the Model 3 will be a good or even popular car. If it flops then this discussion is probably moot or, at best, really premature.

But on the limited evidence we have, Tesla makes a car that surpasses the previously entrenched competition. If it can do the same thing with the Model 3 it will go a long way toward bringing EV technology to a critical mass of production and ownership where at least some of the objections in this thread (price, limited support infrastructure) start to fix themselves on economically justified terms.

We'll see if that happens or not. I'm not making any predictions. It's just fun to watch. And I'll be rooting for the underdog.

 

[explanade]

Article on the plugin hybrid market for the foreseeable future:

The Best Plug-in Hybrid | The Wirecutter

Lot of models are going to be released but most of them offer like 20 miles all-electric range.

 

[ERD50]

I'm completely agnostic on all of this but I don't think we can even really hazard a guess until we see what economies of scale do for us. ....

I agree with much of this post, but I'll challenge a few things...

... Right now building an ICE vehicle is about as cost efficient as it's ever going to get. Building an EV is still heading down the cost curve.

Agree somewhat on EVs and cost curve. But the components - batteries, motors, controllers have been around a long time in similar functions, so the curve might not be as steep as you are thinking.

I'm also not betting against future improvements in the ICE. I went through the numbers a while back, the Prius has seen some considerable improvement in mpg over the years, and is continuing with recent models. In the time frames we are looking at, other options might be feasible (free-piston engines, micro-turbines, heat recovery systems, etc).

We have an entry-level EV in the works that people are excited enough about to part with $1,000 just to get on a waiting list to own one.

Or standing in line to snatch the remaining $7,500 credits with a low risk $1,000 refundable deposit?

We'll see if that happens or not. I'm not making any predictions. It's just fun to watch. And I'll be rooting for the underdog.

And I'll be rooting for whatever makes the most sense overall, not a particular technology - a balance between meeting our transportation needs and reducing pollution. Which takes us back to the discussion you don't care to continue, that until we have an excess of green kWhrs that are regularly available to power a fleet of EVs, they are running on mostly fossil fuel, and creating more pollution than a decent hybrid that anyone can buy today w/o needing to wait for infrastructure or worry about range.

So my question is why even go down this path, other than for niche applications?

Article on the plugin hybrid market for the foreseeable future:

The Best Plug-in Hybrid | The Wirecutter

Lot of models are going to be released but most of them offer like 20 miles all-electric range.

My crystal ball says something like a 10-20 mile range series hybrid (like in that article) is where we may be going. I'll give the run down again:

Start with a series hybrid like the Chevy Volt. Forty mile range on plug-in, then switches to ICE for extended range. Smaller battery pack than a full EV, so lower $/space premium. 110V charging is probably practical for most. No range issues.

Here's the deal with the 40 mile EV-mode range - the car needed enough batteries to accelerate on battery/motor alone. That was the design requirement - decent performance. Poor performance was a deal killer. The 40 mile range was just the result of that requirement. So, looking forward, say we can just get more peak current out of batteries (for acceleration), even if we didn't improve them overall in terms of total energy/size/cost. If we double the instantaneous current draw, we can get by on half the batteries. That cuts our range in half, but so what? The ICE takes over, produces less pollution than from the the plug in the wall, and the series configuration can lead to better efficiency with the ICE running within a 'sweet spot' of speed/power/efficiency (it can just run flat out to charge the batteries - the electric motor deals with acceleration and stopping at idle).

Maybe batteries progress where we can pull 4x the instantaneous current (with no other improvements - just focus on this one attribute), and we use just 1/4 the batteries. Since you reduce the weight, you actually get more than 4x improvement. At that point, you could drive the batteries even harder, to get even more current out - that would reduce their life-span, but it is 1/4 the cost to replace them. There is a point where it makes sense to view them as a recyclable element that you just swap for new every 4 years or so. OK, electric only range is just 10 miles then - but that means you don't start the ICE to just move the car out of the garage onto the street, or to go from one store to another that's a mile away. Since an ICE isn't efficient for start-stop, this will help overall mpg as well. Use both the ICE and the electric motor for what they excel at.

-ERD50

 

[ERD50]

For anyone interested in the technology side of this, I'll expand a bit on the battery "peak current" (or peak power) portion of my previous post.

As I said, the batteries in an EV or series EV need to be able to provide enough instantaneous peak power to provide an acceptable level of acceleration. This is separate from the total energy the battery can provide over the long run. The total energy is what is needed to give you range in miles.

In electronics, power is watts, measured at any instant - like "that toaster is drawing 1000 watts of power while it is on".

Energy is watt-hours (usually described in kilowatt-hours), power measured over time - like "that 1000 watt toaster has been on one hour, it has used one kWh of energy").
​

I mentioned that other factors have driven the improvements in batteries, and this is mostly our portable electronics - laptops, tablets, cell phones, GPS, music players, etc. But for those devices, we are interested in the total energy - we want them to run for a long time between charges. And when we have a big enough battery to run a long time, it provides plenty of peak power for our devices. A GPS or laptop doesn't draw the kinds of (relative) peak power that accelerating a car requires.

What that means is, battery improvements haven't so much been focused on peak power delivery, because that hasn't been the limiting factor. But it is the limiting factor for a series hybrid (the ICE takes over to provide the total energy required).

The first Tesla models are an example of this - with enough batteries to provide the energy for a 200 mile range, those batteries also have enough instantaneous power to accelerate like crazy. But if we use 1/20th the batteries to provide a 10 mile range for a series hybrid, we run into those instantaneous power limits, and we go from 'bat-outa-hell' acceleration to 1/20th of that, and that is unacceptable for normal driving. I don't know if it's linear, but a 0-60 mph time of 4 seconds stretched to 1 minute 20 seconds (20x) just won't cut it.

So perhaps, batteries can be greatly improved in their instantaneous power delivery factor, such that series hybrids are more and more practical?

-ERD50

 

[explanade]

Plug in hybrids probably make more sense for most people.

However, it adds complexity as you have both EV and ICE components to deal with in the car.

One of the nice things about EVs is that you remove a lot of legacy mechanical components. There are fewer parts to build and maintain.

Plus if the best of the plugin hybrids is a Chevy, it isn't exactly inspirational or aspirational. You have to deal with the lack of reliability and cheap materials of a Chevy ICE.

Now the German luxury marques have a lot of plugin hybrids in the pipeline but $50-60k minimum for an electric range under 20 miles? Do people buy luxury cars only for commuter duties?

 

[ERD50]

Plug in hybrids probably make more sense for most people.

However, it adds complexity as you have both EV and ICE components to deal with in the car.

One of the nice things about EVs is that you remove a lot of legacy mechanical components. There are fewer parts to build and maintain. ...

Absolutely. That is one of the reasons that when I was much younger, I fully expected, and looked forward to an EV in my not-to-distant future.

But decades past that point, EVs still have the range and cost issues, and aren't even 'green'.

And in the meantime, we went from changing points & plugs, setting timing, adjusting idle and choke and rich/lean on a regular basis, to ICEs that are almost maintenance free, and emit thousandths of the pollution they used to. An almost unbelievable amount of progress.

So while the complexity is still there in an ICE/hybrid, it really isn't really an issue for most people. And if micro-turbines can make it, you are down to one moving part, oil-less (air-foil) bearings - almost zero maintenance and very simple concept.

... Plus if the best of the plugin hybrids is a Chevy, it isn't exactly inspirational or aspirational. You have to deal with the lack of reliability and cheap materials of a Chevy ICE.

Now the German luxury marques have a lot of plugin hybrids in the pipeline but $50-60k minimum for an electric range under 20 miles? Do people buy luxury cars only for commuter duties?

I don't know, has the Chevy Volt engine/drivetrain been unreliable? But yes, "Chevy" isn't an awe inspiring brand. But there are more coming. I just read about the Prius Prime, due out the end of this year - much along the lines of what we were talking about, a ~ 20 mile electric range hybrid.

https://en.wikipedia.org/wiki/Toyota_Prius_Plug-in_Hybrid#Battery_and_range_2

8.8 kWh battery, so about 1/10th the Tesla S, and 1/10th the range. But this level of hybrid helps when it is gas-only as well. So you can cover most of your short trips on plug-in power (cheap per mile), and then get very good mpg on the ICE when battery runs out, as you get the regen braking, and have a smaller ICE since you still have the battery/motor for a little acceleration boost. 600 mile range on an 11.3 US Gallon tank! So over 50 mpg in gas/hybrid mode.

And you can probably actually buy one at the end of this year.

I just think future EVs are going to have a tough time competing with that, outside of niche applications.

-ERD50

 

[mpeirce]

I just think future EVs are going to have a tough time competing with that, outside of niche applications.

Tesla has a good plan on the high end, but there is a low end that I'm surprised no one is pursuing.

In Florida (and other places) there are lot of locations where people use "golf carts" as local, run around town transportation. I know these aren't "cars" and lack much of the safety and comforts of a real car (i.e. doors), but it seems like someone would be evolving them up to "real electric car".

Maybe someone is working on this and I just haven't heard about it?

 

[NW-Bound]

For anyone interested in the technology side of this, I'll expand a bit on the battery "peak current" (or peak power) portion of my previous post.

As I said, the batteries in an EV or series EV need to be able to provide enough instantaneous peak power to provide an acceptable level of acceleration. This is separate from the total energy the battery can provide over the long run. The total energy is what is needed to give you range in miles.

In electronics, power is watts, measured at any instant - like "that toaster is drawing 1000 watts of power while it is on".

Energy is watt-hours (usually described in kilowatt-hours), power measured over time - like "that 1000 watt toaster has been on one hour, it has used one kWh of energy").
​

I mentioned that other factors have driven the improvements in batteries, and this is mostly our portable electronics - laptops, tablets, cell phones, GPS, music players, etc. But for those devices, we are interested in the total energy - we want them to run for a long time between charges. And when we have a big enough battery to run a long time, it provides plenty of peak power for our devices. A GPS or laptop doesn't draw the kinds of (relative) peak power that accelerating a car requires.

What that means is, battery improvements haven't so much been focused on peak power delivery, because that hasn't been the limiting factor. But it is the limiting factor for a series hybrid (the ICE takes over to provide the total energy required).

The first Tesla models are an example of this - with enough batteries to provide the energy for a 200 mile range, those batteries also have enough instantaneous power to accelerate like crazy. But if we use 1/20th the batteries to provide a 10 mile range for a series hybrid, we run into those instantaneous power limits, and we go from 'bat-outa-hell' acceleration to 1/20th of that, and that is unacceptable for normal driving. I don't know if it's linear, but a 0-60 mph time of 4 seconds stretched to 1 minute 20 seconds (20x) just won't cut it.

So perhaps, batteries can be greatly improved in their instantaneous power delivery factor, such that series hybrids are more and more practical?

-ERD50

The current lithium battery is there already!

I looked up the specs of the P85D, the most powerful version of the Tesla that boasts the "ludicrous" acceleration with nearly 700HP from a 85kWh battery pack. The power demand is around 550kW or half a megawatt!

The current drawn is 6.5C (6.5X the current that would deplete the battery in 1 hour). But how is that compared to the battery specs?

A search on the Web shows that the common 18650 cell that the Tesla pack is built up with can even do 15C for short periods! Lithium batteries have low internal resistance and are head-and-shoulders above other types of batteries. Amazing!

The problem in practical applications is managing the heat in a pack, plus the equalization of the cells inside the pack. And the P85D has a 2nd motor to give it that power.

My question is still: how long do they last? I have replaced the lithium batteries of my laptops often. If I have to do that with an EV, that will mess up my WR.

 

[ERD50]

The current lithium battery is there already!

I looked up the specs of the P85D, the most powerful version of the Tesla that boasts the "ludicrous" acceleration with nearly 700HP from a 85kWh battery pack. The power demand is around 550kW or half a megawatt!

The current drawn is 6.5C (6.5X the current that would deplete the battery in 1 hour). But how is that compared to the battery specs? .....

My question is still: how long do they last? I have replaced the lithium batteries of my laptops often. If I have to do that with an EV, that will mess up my WR.

Interesting - I hadn't run those numbers, but I had thought about them a little.

But I'm guessing that your last question is the issue. A Tesla driver is going to punch it only occasionally, but a low cost, modest performance car with just enough batteries to get by, will be pushing them to the limit fairly often. And that degrades the overall lifetime.

But that's just a rough cut, a more detailed analysis would be very interesting. And I'm not a chemist, so I'm not sure what really limits the peak current ratings on lithiums. Obviously, heat is one, as you mentioned, but I think there is some chemical degradation that occurs, and maybe something could be optimized there for a series hybrid?


Ohhhh, and a little more reading I was doing shows that these battery sizes aren't all purely technical decisions. Our non-technical-degree-holding members of Congress have passed laws that make a tie-in between battery capacity and the tax credit, so EV/hybrid manufacturers size their batteries with consideration to the laws of Congress, rather than the laws of physics!

edit - quick add off the top of my head - I started playing with micro-quad RC coptors (fit in your hand, cost ~ $16), and they use little 100mAh lithiums (roughly the size of little finger tip to first joint), and some are rated around 15C, some even more I think, if you spend a little more. But no one is expecting these to last 10 years!

-ERD50

 

[NW-Bound]

Yes, lithium batteries are one of the things that enable the quad rotor. They allow a huge current drawn despite their minuscule size, in exchange for a proportionally shorter operating time. Other batteries just cannot do that; their capacity drops off rapidly with higher power demand.

Anyway, on the life of the lithium battery, an often-quoted number is a life of 2000 cycles. If an EV has a range of 200 miles, that translates to 400,000 miles. Surely, that would be plenty good.

Manufacturers claim the 2000-cycle number based on lab testing, where they drain the batteries to near depletion then recharge them. In normal applications, the batteries are not stressed as hard, so perhaps they should last even longer. But is it so?

Look at a laptop, or a smartphone for example. If you run them to depletion, then recharge them once per day, that 2000-cycle life works out to 5-1/2 years. But, but, but replacement batteries for them appear on the market for sale long before that date. So, is that 2000-cycle number as imaginary as the decade-long life claimed for CFLs and LEDs?

 

[ERD50]

...
Anyway, on the life of the lithium battery, an often-quoted number is a life of 2000 cycles. If an EV has a range of 200 miles, that translates to 400,000 miles. Surely, that would be plenty good.

Manufacturers claim the 2000-cycle number based on lab testing, where they drain the batteries to near depletion then recharge them. In normal applications, the batteries are not stressed as hard, so perhaps they should last even longer. But is it so?

Look at a laptop, or a smartphone for example. If you run them to depletion, then recharge them once per day, that 2000-cycle life works out to 5-1/2 years. But, but, but replacement batteries for them appear on the market for sale long before that date. So, is that 2000-cycle number as imaginary as the decade-long life claimed for CFLs and LEDs?

From what I recall, the car makers limit the charge levels in the batteries for hybrids and EVs. Something roughly like charging to only 80%, and discharging to 40% of their normal specs? In effect, only using ~ 40% of the actual capacity, to extend the life. So a Tesla 85 kWh pack is 'really' ~ 212 kWh? That is part of what makes them expensive (plus they need to be small, light, crash-worthy, and survive and work in extreme environments, not just room temp).

Laptop batteries, I think, are pushed to the extremes, so they don't always last as long. But replacements are fairly cheap, and easy to swap, so a minor inconvenience.

But if the 2000 cycle number you mention is a full charge/dis-charge cycle, then it does seem the laptop batteries should last that long. I seem to remember a number closer to 300 cycles (of full charge-discharge, a half charge would only count as half), but my memory is not so good, and that may have be an outdated number. Maybe I will search it later.

-ERD50

 

[NW-Bound]

No, I believe the Tesla battery is really 85kWh, not derated down to 85kWh.

The NiMH batteries in earlier hybrid cars and also the old lithium ion batteries lasted longer with shallower charge/discharge cycles. But what I have read about the latest LiFePO4 (lithium iron phosphate) batteries say that they can stand up to near 100% depth of discharge, and supposedly still have 80% or more of original capacity after 2000 cycles. In addition to that robustness, they also can be punctured and will not explode in flames, and are safe for use in aircraft.

As LiFePO4 batteries have been around for 5 years now, I assume that they are being used in modern electronics, but who knows?

 

[NW-Bound]

Inside a Tesla battery pack are the industry-standard 18650 cells that look like this (slightly larger than a common AA alkaline). One version of the pack has 6,800 cells, for a cost of $45K. That makes each cell cost around $6.6. This is about the right price for a loose Panasonic cell one can buy on the open market.

eBay shows a bunch of no-name 18650 cells for $1. Given the propensity of aftermarket cells to burst in flames, I was tempted to get a few to play with, but decided against it.

See photo linked from the Web:

 

[Totoro]

Manufacturers claim the 2000-cycle number based on lab testing, where they drain the batteries to near depletion then recharge them. In normal applications, the batteries are not stressed as hard, so perhaps they should last even longer. But is it so?

Look at a laptop, or a smartphone for example. If you run them to depletion, then recharge them once per day, that 2000-cycle life works out to 5-1/2 years. But, but, but replacement batteries for them appear on the market for sale long before that date. So, is that 2000-cycle number as imaginary as the decade-long life claimed for CFLs and LEDs?

Anecdote isn't data, but still. Just replaced my laptop, after [-]three[/-] four and a half years of heavy duty use. Battery capacity was at 55%. Figure that's at least 2000 cycles.

Cellphone is only two years old, battery is less than half. It's always on and recharges two to three times a day now. So also 2000+ cycles I guess.

The thing with phones is that heavy use drains the battery really quickly, so you end up charging it more than once a day.

 

[Totoro]

From what I recall, the car makers limit the charge levels in the batteries for hybrids and EVs. Something roughly like charging to only 80%, and discharging to 40% of their normal specs? In effect, only using ~ 40% of the actual capacity, to extend the life. So a Tesla 85 kWh pack is 'really' ~ 212 kWh?

My brother owns a Tesla S. Standard charging is 80% to prolong battery life, but you can ask the car to charge up to 100%. It's what you prefer.

Likewise, advice is to keep it charged above 20% but nothing stopping you to ride it until empty.

 

[NW-Bound]

I just thought of another thing: the difference in configuration between a laptop pack and a larger pack. It makes a difference in the effect of random infant mortality that can have a cell not lasting as long as the average life of the production lot.

Lithium batteries have a nominal voltage of 3.2V or higher, so small electronics can run off a single cell. Laptop packs are usually multiple cells in series, typically 5 or 6. So, if one cell of a laptop pack goes bad, you toss the entire pack.

On the other hand, larger packs for EVs are of more complex series/parallel connections. One version of the Tesla pack has 74 cells wired in parallel, then 6 of these groups are wired in series in a module. Then, 6 modules are put in series again in a complete pack, for a total of 74 x 6 x 16 = 7104 cells.

Because a bad cell is in parallel with 73 others, one bad cell only impacts 1/74 = 1.4% of capacity, not ruining the entire pack as with the laptop.

 

[ERD50]

... But what I have read about the latest LiFePO4 (lithium iron phosphate) batteries say that they can stand up to near 100% depth of discharge, and supposedly still have 80% or more of original capacity after 2000 cycles. ...

Cycles life of 2000 wasn't ringing any bells for me, I was thinking ~ 300~500 cycles, and this spec sheet for an 18650 confirms that, with degradation to about 72% of 'typical starting capacity' (eyeballing 2200/2900):

http://industrial.panasonic.com/cdbs/www-data/pdf2/ACI4000/ACI4000CE17.pdf

But, that is at .7C charging rate. Wiki mentioned home chargers are 10kW or 20kW for the 60kWh Tesla battery, so that's 1/6 (.167 C) or 1/3 (.33 C) rates, so longer life assumed, but no charts on that.

And a one hour supercharge would be 1C, but assumed you don't do that very often, and I think they encourage a 50% or 80% charge when you use them?

I also see that Telsa warranties the 60kWh pack for 125,000 miles, so using a rough 200 mile range, that is 650 cycles, so maybe reasonable if 500 cycle rating is at the higher .7C. And of course, warranty doesn't imply it will fail/degrade in that time, just that they cover you if it does, and one would assume they have some safety margin built in.

So just a very rough cut, but from this I'd guess they really don't de-rate the cells much, if at all, that the cells can handle this charging for the 'life' of the car. But you might need to accept some range reduction of 20-30% when you get up to 150,000 miles or so?

I'd also assume that battery cycle performance will improve as they tweak battery chemistry, so not so bad. Much bigger deal if you only have 80 mile range to begin with.

-ERD50

 

[Chuckanut]

Here's a short discussion of a new type of lithium storage battery that promised a big increase in energy storage if it works out. And, it keeps its ability to hold a full charge through many more cycles than today's lithium batteries. Again, if it works out.

https://www.grc.com/sn/sn-552.htm

The discussion of the new battery takes place about 80% down the transcript.

So not yet on the market, but nothing to leak. It is solid. Because it's solid they're able to get 20 times the lithium-ion content in the same space as a fluid because this matrix actually holds them and allows them to move through the crystal matrix. So I just wanted to bring it up as another interesting little bit of energy storage tech. Maybe this will be the one.

 

[Totoro]

But you might need to accept some range reduction of 20-30% when you get up to 150,000 miles or so?

Information seems to conflicting and scarce, I like this site:
How to Prolong Lithium-based Batteries - Battery University

Depth of discharge seems to play a huge role. At 100% discharge depth you get less than 500 cycles before capacity is <70%. At 50% it's a factor three higher (!).

Same thing with temperature, higher temps degrade the pack quickly. Apparently that's why the Tesla S has liquid cooling running around the pack.