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You Need Way Less EV Range Than You Think: Study
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this post was submitted on 22 Feb 2024
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[Dormant] Electric Vehicles
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I mean just that.
The internal chemical structure of Li-ion is only designed to work for a limited number of charge/discharge cycles. As the chemistry is stressed out, the internal metals begin to form dendrites (or in more simple terms, spikes) internally.
We have reasonable estimates for how long this takes, but everyone's battery pack is different. And the process is invisible (you have to cut open & destroy a battery to figure out how much of these dendrites or whatever have formed). So the best we got are some computers slapped on the outside of the battery pack that measures temperature, voltage, current, and time to guestimate the effects from the outside.
As cells fail, modern BMS systems will reroute power away from degenerated cells. Its not that the problem was solved per se, its that modern battery packs have a bunch of extra cells waiting in reserve to pretend that nothing has happened to the end user. But this process eventually breaks enough cells that the whole pack fails and inevitably needs replacement.
Exactly when depends on how many cells were left in reserve, how much "fast charging" you do (which is extremely harsh on the internal chemicals), the temperature of the pack under use, and any aggressive driving you might do that heats up the pack more than usual.
Its... really complex. There's a lot of research going on right now to try to stop these dendrites from forming.
EDIT: In any case, Consumer Reports reliability surveys on various parts of say... a Toyota Prius Prime or other PHEVs. Go look at them all, see what parts fail. Its the battery.
Here's GM Volt. What's the problem? Oh, the EV Battery again, and looks like the EV Charger is also terrible cause GM must have messed that up too.
But yes, its the electrical parts that are more complex and prone to failure in almost all of these cars.
Here's Chrysler Pacifica. Oh boy, lots of parts of this vehicle is terrible. But as predicted, the EV Battery is among the worst of parts again.
You chose GM and Chrysler as your reliability targets…………
A 40mi PHEV battery is getting a lot more wear put on it from going 0-100% than a 300mi battery that’ll bounce between 50-80%
I chose Toyota first for a reason. The other two are just common PHEVs that came to my mind.
In all three cases, the Battery Pack is one of the least-reliable parts of the car. Even for notoriously unreliable cars, the worst part remains the battery.
I'm not kidding when I say that the battery pack is one of the most complex and least-understood parts of EVs, Hybrids, or PHEVs.
EDIT: Wanna go Honda? Guess what part was least reliable again.
I’m sorry but this just sounds like trying to justify a potentially already-made PHEV purchase more than anything by cherry-picking strange bits of data.
Try Hyundai or Tesla instead of picking literally the worst brands lol
Gas engines just don't fail today man. It will almost always be the battery pack. Stats prove it.
I've looked at a fair number of these different vehicles from different manufacturers.
This is utter horseshit. Gas cars fail way more because they have way more parts and all of those parts require more maintenance.
I would know, I bought a house and put a kid through college with the money I made fixing gas cars and now I’m changing careers cause EVs are taking over and they rarely break.
The batteries degrade over time slowly, especially compared to gas engines. Just compare the warranties! Gas drivetrains get 3 year / 36k mile warranties. EV battery warranties are 8-10 years.
Um....
You know that Hyundai has a 10 Year, 100k mi Engine warranty, right?
Yes I know that. Because they are the only one that does. That’s why it’s called cherry picking.
Your stats prove you can cherry-pick among the notoriously worst of brands for electrification, but not anywhere near the point you want to make.
The concern is that you have basically two different drivetrains to worry about, where if either fail you're (potentially, depending on what/where/etc fails) without an operational vehicle at worst.
Meanwhile, the Toyota Prius has been sitting on the top reliable cars for the last 20+ years...
There's like, statistics... ya know? We don't have to hypothesize the problems or "expected" problems. We can look at these cars and their long history now and see where the problems occurred.
The Prius is a solid vehicle but let’s not pretend that you don’t have to replace the battery after several years… it’s a small battery, it gets a lot of wear. It’s also a few thousand dollars.
Sure, a PHEV battery a bit larger and might postpone things a bit longer but why sign up for a future guaranteed replacement item?
Because replacing a 200lb battery is easier than replacing a 1000lb battery in a full EV.
You're right. Battery packs have limited durability / cycles. Its just how the chemistry works. The question is if you want to have a 200lbs of it or if you want 1000lbs of it.
Like seriously, do you look up stats?
If you’re going to snark, do understand your sources first. Consumer Reports uses a “what they think will happen” for the reliability of a given item, it is not a wholly objective figure. They aren’t stats.
It’s a wonderful tool for a purchasing decision where you want to be cautious and consider the worst case scenario but it isn’t useful as a tool for much else.
Considering the vehicles you chose have low volume, do understand something:
The stats I posted are history / survey results.
Consumer Reports conducts surveys where they ask car-owners of various model years how many issues, and what kind of issues, their cars have.
I know the difference from "predicted reliability" and their "Reliability history" page. There's a reason why I'm posting history. These survey results look back into the past and is more appropriate for our discussion.
https://www.consumerreports.org/cars/car-reliability-owner-satisfaction/car-reliability-histories-a1200719842/
Before criticizing my methodology, you probably should see what pages I'm posting and understand the material I'm quoting.
Oh look. We even got overall% problems.
Guess what? Its the battery again.
The only actual data you have is the percentage of problems being reported.
Re-read your page on reliability history, the scores aren’t much of a measurement and are derived from some in-house weighting of several things including comparison against other vehicles.
I'll take the 3% as-is, but part of me is wondering if "battery problems" may be a catch-all for other self-reported electrical problems. It'd be alarmingly close to "moving goalposts" to assert anything, though.
Consumer reports states:
That's it. There are other categories for electrical problems. Ex:
The Consumer Reports Survey is very clear. "EV Battery" problems mean exactly the battery. There's other categories for other cases.
The whole table didn't fit inside of my screenshot. (I can only screencap what is on my screen...). The "In Car Electronics" also have a 3% failure rate, but are at the bottom of the chart. But between that and EV Battery, they are the #1 failure points of a modern car.
You really have a bone to pick this evening, huh? Grab a beer and relax my friend.
Yes, and I’m deliberately wondering because it is self-reported data. Data that relies on an accurate assessment from whoever is doing the repair as well as the owner. Both of which are brand new to the tech if you’re picking first year models.
He’s been posting like this in multiple threads with one or two others. The way he’s pushing hybrids and talking up Prius makes it seems like a Toyota shill.
Of course it’s the battery. Nothing else breaks on an EV!
Similar to the rising rates of cancer these days because people are living longer and surviving everything else more due to medical science.
https://www.consumerreports.org/cars/car-reliability-owner-satisfaction/electric-vehicles-are-less-reliable-than-conventional-cars-a1047214174/
It is physically impossible for an EV with much fewer parts, all of which require no maintenance, to be less reliable than a gas car with highly complex parts like transmissions and differentials and combustion engines.
I’ve worked on both for a living. I’ve seen first hand which cars come into the shop and how frequently. I used problem tracking websites like Identifix daily to see common failures on all the cars I work on.
EVs rarely break.
Gas vehicles turn into paperweights if you go too long without changing the oil.
And transistors, and transformers, battery management systems, and inverters aren't complex?
Are you making fun of my degree? Power engineering is a masters-level subject at a minimum, and easily reaches into the PH.d level.
As I stated earlier. I've got an electrical engineering degree. When EV buffs talk about the "simplicity" of EVs I can't help but roll my eyes. Yall probably can't even pick out the right chips for a Li-ion BMS, or tell me the differences between LiFePo4 or NMC Li-ion is.
There's some highly technical magic going on here. MOSFETs, Power-circuits, complex inverters, microcontrollers to carefully time the movement of electricity with the movement of those magnets. There's a hell of a lot more complexity in there than people realize. And when things go wrong, there's not much else to do but replace the entire damn part, because it requires a very advanced facility to create electric motors, the chemistry behind these cells, or PCBs for those battery packs.
Moving parts wear out due to friction. The electronic parts you listed are not moving parts and rarely fail. I would know, as an automotive technician they come to me when they break.
If you really were an engineer, you would know about minimizing points of failure. And you would be able to recognize gas vehicles have exponentially more points of failure due to the amount of moving parts and sealing surfaces and combustion temperatures.
It’s easy to claim you’re an engineer on the internet. But you’re definitely not talking like an engineer.
Hear hear.
Engineers look at empirical results most of all. They don't dismiss large, 300,000+ car surveys just because they're inconvenient to your argument.
I've said my piece on the reliability of battery designs over the past 5 years. Hopefully battery engineers improve their reliability moving forward. I don't think it's going to be easy though, as the simulated models of the internals of Li-ion cells is just such a devilishly difficult problem.
Technical magic???
BMS systems are far from it. Lots of technical work going into simplifying measuring techniques, automatic switching between series parallel linking of cells based on system needs (at my company)... but the essentials of measuring current, thermal and voltage? Lmao. I'm making fun of your degree, as a holder and EIT myself.
If you're into BMS systems at all, you know that the ridiculous levels of modeling are chemistry / cell specific, to the point that would make the typical layman's eyes glaze over. A litany of cell types (NMC, LiFePo4, NCA) and more as new chemistries are invented (or go in and out of fashion) requires updates to BMS, the modeling of how the internals of the cells work, and how all of that is related to the voltage/current/temperatures of individual cells.
Measuring voltage/current? Yeah, that's easy.
INTERPRETING voltage/current? That's the hard part. And requires a giant mess of R&D effort on these cells and their individual chemistries.
There's nothing "simple" about that battery pack. The shear number of control systems that go into a modern battery-pack it should be proof enough to you.
https://stock-tesla.com/en/asy-tested-bms-96s-mdls-1021970-00-b
Not only is there difficulty in building and manufacturing this... there's also difficulty in maintaining this item. I mean yeah, we don't maintain it, its just replaced wholesale. But there's also the whole 400V will-instantly-kill-a-technician problem if they're not careful.
Sorry, I have designed complex 4 and 6 layer high speed FPGA boards, this BMS board looks moderately dense but not crazy, nor does it look like it's dealing with high speed signaling.
Try dealing with RF or something, those PCBs are quite a bit crazier.
The models for the cells are implemented in software. You know what's easy to update in place? software. You know what's hard to update in place? Mechanical systems. That's my point.
Then I'll chalk it up to another FPGA programmer dissing Power Engineering and the complexities of handling of high voltage lines.
Lmao go for it, I deal with systems shoving kiloamps at multi-tens of kv around quickly, I'll chalk it up to a small fry "power" electronics engineer not knowing better, as is customary for you so far.
GaN MOSFETs, because igbts are too slow, tech you, @dragontamer@lemmy.world, haven't even gotten to touch yet. TeChNiCaL MaGiC in your parlance.
So you do touch BMS systems and understand that the hundreds or thousands of MOSFETs that control the electrical currents of a ten-thousand cell battery pack are arranged in systems of series and parallel ... Running advanced modeling software that tries to peer into the internal chemistry of modern cells...
Yet you want to convince me that this is simpler than the like, 15 gears that make up Toyotas Powersplit Device?
In the long run, yes.
How do you account for tribological degradation in tolerances over time? There are techniques to negate the problem entirely, my 40+ year old Japanese motorcycle uses high-ish pressure hydrodynamic bearings to allow oil to be the "wear" surface... But it isn't foolproof.
Newer techniques rely on better metallurgy, oil additives which precipitate on designated surfaces, etc etc etc. It's one of those things you and I have both observed where the more you look at it, the more complex it gets.
Now change gears (haha) and observe the complexity of analog/digital systems. You and I front-load the complexity, so that any configuration changes should (mostly) be possible in software. "Oh no, we didn't use this particular junction of p-n MOSFETs"... They added $3 to the BOM, but our flexibility/redundancy is increased.
Look, you should know as well as any EE that solid state systems, when run within parameters, have a tremendous unchanging mtbf. While there are currently issues with undersizing MOSFETs and igbts, I expect our engineering models (in our heads) of what to expect from these evolving electronic components to adapt to these new operating environs, the already reasonable reliability will only increase.
Failure of these packs and their bms' are low enough that we can point to specific failures, versus how often we see someone with serious ICE engine issues in the local mechanic's shop.
If I have a 400 V 50 kWh battery and charge at 400 V 50 kW, won't it be charging at 1 C? Like you could use the Nissan leaf as an example but it's dishonest since it's the worst type of battery cooling, air, which makes the cells die prematurely.
Tesla is one of the more failure prone brands. Hybrids are a bad solution since it won't address the problem fully, and only serves to lengthen the ICE industry.
Don't let perfect be the enemy of good.
There's no perfection in engineering. Just a series of compromises. Anyone who is an absolutionist is going to have a bad time in engineering, policies, and politics.
Using fossil fuels in ICE is a waste of resources
Agreed.
Which is why converting 100-million ICE cars to 100-million Hybrids is our best chance for reducing our fossil fuel consumption.
We are Li-ion limited right now, and will continue to be Li-ion limited for the near future. Hybrids are magic technology because not only is Li-ion chemistry available, but also cheaper/easier to manufacture NiMH (Nickle Metal Hydride), which grossly reduces fossil fuel consumption on the order of 30% to 40%. (50mpg vs 30mpg is 40% savings).
You wish to deny the intermediate step just because... of your weird obsessive compulsive desire of perfection? We all know that 100-million EVs is out of the picture, even on the scale of 10 years of progress and production. We're literally going to run out of Lithium by 2025 and become production constrained.
When the battery tech is ready. Sodium-Batteries are coming as are Silicon-Lithium, both of which will improve our chances. There's also recycling centers that aren't functional yet before Li-ion is a truly green solution.
How many EVs do you think can be made in the next 10 years? Now multiply that by 5 to 20 (because PHEVs / Hybrids use 5x to 20x fewer batteries than a pure EV). How much fossil fuel savings do we get from 20x more Hybrids (or 5x more PHEVs) ??
Its an intermediate step, but economically speaking its a necessary economic step because its more efficient to transition from ICE -> Hybrid/PHEV -> EV, than to not do so. Especially given the economic realities of spinning up Li-ion production.
Lmayo converting 100 M cars is not realistic either
There exists a Hybrid in every vehicle segment, and its technology available to Toyota, Honda, Hyundai, Ford, GM, Stellanis, BMW and more.
The only reason we're not converting to Hybrids is because online idiots have decided to kill the idea and never give them a proper try. But the market is healing, people are realizing how reliable and practical they are today.
EVs should continue developing of course. But the immediate best move for our society is to immediately move to hybrids and off of traditional ICE. And the technology is in fact, available today... and at cheap prices... to allow for such a move.
What we need is EV fans to get off the backs of people buying a $23,000 Corolla Hybrid or $25,000 Ford Maverick. They need to congratulate these car drivers for making a better environmental choice and something that fit their budget. Trying to get the poor or middle class to buy $40,000+ class EVs is insane. It feels even more insane to fund that through $7500 tax credits, but even with that tax credit the Hybrids are still winning out.
The US has a deeper systemical issue of corruption regarding energy sources and pricing, I'll agree that hybrids are the better solution when ICE fuels pay to carry their costs.
Another EV fanboy complaining about corrupt taxes and policies who likely benefits from $7500 direct handouts as well as pays $0 in gas tax aka how most states pay for Road Infrastructure.
Politics is shit. Let's not go there. There's black marks everywhere.
Btw. I support EV subsidies. But I admit that they are in fact, one of those subsidies you are complaining about. I feel like the subsidy regime favors EVs and therefore we EV fans should celebrate it... not bite the hand that feeds us.
We aren't going to reach widespread adoption of electrified transit unless we have large scale subsidies like this.
What? This conjecture is nonsense
.... chrysler what are you doing
That Chrysler Pacifica is one of the few electrified solutions with 7 comfortable seats.
Despite that terrible reliability, its one of your best family-van options if you care about electrification at all. You just gotta grin and bear it.
It's interesting to be on the other side of watching a subject matter expert being downvoted by laymen suffering from Dunning Kruger. Their feelings will always Trump your knowledge.
I've read enough on these systems to understand you're speaking the truth here. Thanks for trying. I learned some new details on these system's complexities.