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enjoyoutdoors t1_j2310j0 wrote

More often than not, they DO have a lot of smaller batteries that can be swapped out based on need.

It's just that, eh, the batteries are a safety hazard for rescue services when the cars are in accidents, and to make them less of a hazard they are combined into a large container that is comparably good at confining the hazard.

There are other reasons to, such as thermal control of the batteries and weight distribution concerns.

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PoLoMoTo t1_j24qijl wrote

To add on to this, yes some cells will die before others but in general when the battery pack is nearing the end of its life none of the cells are going to be very good anymore and you'd probably end up replacing all of them anyway. Additionally combining brand new cells with old worn cells is probably not a great idea for balancing.

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sold_snek t1_j24xoq9 wrote

I remember seeing a case where Tesla was charging wild money to replace a battery and the dude paid another company to look it over. While still expensive, it was a lot cheaper for the guy to go battery by battery and find the bad batch then replace it and car was good again.

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PoLoMoTo t1_j24z9ee wrote

I have no doubt that would work but I would be curious as to the longevity of that. Also if it was a high mileage battery or some fluke internal failure, and what percentage of the cells they actually replaced. I'll have to try to find the story sometime.

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greatvaluemeeseeks t1_j25e83m wrote

A few companies do this with Prius batteries and sell them as refurbished batteries. The cells aren't too hard to disassemble and a dead cell is pretty easy to isolate. A refurbished battery is much cheaper than a brand new one from Toyota, but the batteries don't last very long before another cell eventually dies since they probably have 150k+ miles on them and Toyota, in my opinion, provided inadequate cooling for them and should have told consumers the battery's cooling system required regular maintenance.

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Lyrle t1_j26gnwi wrote

Rich Rebuilds had an episode like this. The car featured there was not very old.

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ikingrpg t1_j261dqp wrote

Yeah, that was a rare case where the car wasn't that old, but one cell just went bad. You wouldn't want to do the same thing if all the cells were old.

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Bensemus t1_j2co8yg wrote

This is just the difference between dealership repairs and independent garage repairs. Tesla isn’t interested in diving super deep and doing a one off fix. They do high level repairs which cost more.

It also shows that Teslas aren’t locked to Tesla like so many claim. You can bring it to other people to get it fixed.

1

sold_snek t1_j2csqgs wrote

> You can bring it to other people to get it fixed.

You need literal electrical engineers to do it and Tesla won't touch your vehicle afterward. It's a pretty big cost to do anything outside of Tesla.

1

rickymilby t1_j25y914 wrote

This is correct, you can't mix new batteries and old batteries as it is impossible to balance.

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WiryCatchphrase t1_j24v28y wrote

There's some confusion here. Batteries by definition is a collective noun and are comprised of cells. EVs are comprised of many cells controlled by computer processors to manage usage heat and life cycle. Generally you don't want a cell to get about 80% or. Below 30% capacity, nor do you want to wear out a handful of cells charging and recharging constantly becuase they're closer to the inlet/outlet.

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ShwAlex t1_j26rjhj wrote

Microvast has fire proof batteries now!

1

BazilBup t1_j25911t wrote

Also Tesla have built int rhe battery into the core chassi so they save on weight. And yes you can upgrade individual cells which can be done on old bicycle batteries.

0

Commercial-Army2431 t1_j23439h wrote

Maybe loss of efficiency with added resistance between multiple batteries and systems? Idk???

−8

DoomGoober t1_j23sdmh wrote

As I understand it, car batteries are arranged in packs of serial or parallel configurations to intentionally harness the resistance of serial or parallel to achieve desired voltage.

Thus using multiple batteries (and the resistance introduced by serialization or parallelization) gives the designer some control over the voltage.

Whether this is a side effect of needing multiple batteries for other reasons or a specific desired feature, I don't know, but it reduces the need for resistors.

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VrebPasser t1_j24m8z3 wrote

Not quite true as you put it, but the general principle applies. It's about voltage stacking and the same current being drawn from multiple sources.

Think of it as a slide going from the top of a building to the road below. You have a number of people that want to slide down (that would be the load). If you have one huge slide, the people will be hurting each other as they descend. Therefore, you add more paralel slides (batteries) so they can redistribute themselves and be less cramped (less overloaded system). By adding more batteries in series, you make the slope more steep so the people get down faster (more force to "push" them).

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Commercial-Army2431 t1_j242rbp wrote

Weird I’m being downvoted. I thought I was asking a legit question. Oof

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OhNoItsThatOne t1_j243z7d wrote

That was not a question, it was a speculation. And too many question marks. (I didn't downvote)

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corsicanguppy t1_j247xg8 wrote

And the last question was asking us whether he didn't know. That's something we can't really answer without telepathy.

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veloace t1_j244l94 wrote

It's the question marks.

Usually people use multiple question marks like that when they aren't asking a real question but asking a rhetorical question to make the OP sound like an idiot. Usually in the context of trying to point out "obvious" information.

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Commercial-Army2431 t1_j2451f6 wrote

I can see how that would read like a snarky belittling response. It was not my intention.

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veloace t1_j24ex8t wrote

I know it wasn't your intention, just trying to give you some insight on the downvotes. People here will read punctuation before they read the words.

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PckMan t1_j231hxg wrote

These huge batteries are made of smaller batteries. Making them modular would make them heavier, bulkier, and possibly more dangerous since at any one point someone could tamper with them and do something wrong and cause a huge fire risk, whereas sealed batteries can have more compact wiring and are considered bad and in need of replacement if there's any damage to them. That might seem wasteful but the fire hazard is big.

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wombatlegs t1_j2405w4 wrote

smaller batteries? Do you mean cells?

−1

moresmallerbear t1_j24z3mi wrote

all of the EVs I know of are batteries made of batteries. The individual modules are multiple cells, those are then stacked together.

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BathFullOfDucks t1_j256stx wrote

Tesla batteries are literally just a lot of Panasonic 18650 batteries (ie, the lithium aa) wired together. They're not modular because it's a mess.

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DragoonXNucleon t1_j240gjc wrote

I don't buy it. Car companies don't want it to be modular because it doesn't benefit them. In Asia they have grab and go batteries in motorbikes all the time.

Why would Tesla or Toyota want to cooperate and build a modular battery so that a competitor could sell a battery for your car. They don't want duracell in the game.

Government could fix this, but won't because captured capitalism.

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photogypsy t1_j244nja wrote

E motorcycles are not even in the same planet for weight and size comparison. Also voltage. EV car batteries hold huge amounts of voltage (exponentially more than an electric motorcycle battery) and something as simple as mishandling could lead to deadly results while doing something as routine as swapping out the packs. Plus architecture. Batteries aren’t under the hood; they’re in the floor pan. There are lots of reasons. Formula E racing doesn’t use modular batteries; they swap the driver over to a new car when they pit. If modular batteries were feasible; they’d be doing it already.

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PckMan t1_j243t4c wrote

Grab and go batteries for what exactly? Lead acid batteries for gasoline powered motorcycles or batteries meant for electric scooters and mopeds?

For starters when I saw modular batteries I mean batteries in which you can swap out individual cells as the original post suggests, not whole batteries you can swap in and out of a vehicle. Secondly though car makers could standardise batteries between them this would severely limit them in many ways. We like to think of batteries as the equivalent of a gas tank in an internal combustion car but that's not exactly the case. Yes batteries store an amount of power inside but the role of the fuel pump is also up to the battery, that is the rate at which it can charge or discharge has to do with the battery. Moreover the weight and shape of the battery changes from manufacturer to manufacturer and in many cases the battery housing serves as a structural member. This means that not only the capacity and therefore range are determined by the battery but also the charging times, power output, vehicle handling and weight distribution and chassis construction. So if you limited manufacturers on using a specific set of batteries, they'd all basically have to make the same cars, just with different looks. Two cars using the same battery but different electric motors would still have the same maximum power output at the wheels which is limited by the battery, a stronger motor wouldn't be able to draw power at a faster rate to output more power to the wheels.

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Admirable_Remove6824 t1_j250nt4 wrote

They do have electric bikes with standard batteries. They do have battery swap locations. If they aren’t the same brand then they must have a standard type they use. Like a propane gas tank swap place. I’m sure it would be hard right now to standardize car batteries because the technology is changing relatively quickly. The biggest issue is not having “right to fix” laws in the US. Companies are allowed to continue to make money off of cars, tractors and other products after you buy and own them. They keep a monopoly and if anything this slow technology advancements with proprietary rights. When car companies first started making cars there biggest advantage was aftermarket opportunities. Now if you buy a Tesla or such you can’t modify or repair without permission from them. Monopoly’s delay progress. We might be flying electric cars but now without oil monopoly’s!!

1

jontss t1_j243ran wrote

There are multiple YouTube videos of people fixing battery packs for free or nearly free where the dealers insisted the whole thing needs replacing. In one case it was just a dirty connecting plate.

But this applies to most car repairs. $3 microswitch on the lock assembly failed? Sorry, you need a $300 lock assembly. Oh your turn signals stopped working because of some oxidation on the column contacts? Well we could spray 20¢ of contact cleaner on it but instead we want $1000 to replace the stalk assembly.

Could go on and on.

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danielszajkowski t1_j248o2h wrote

There are multiple reasons why you can only buy things as assemblies.

Including having few parts to keep in stock. And some of these parts are not designed to be taken apart. Plus the labour to change the failed part of the assembly can be cost more then then new assembly. Assemblies are designed to reduce the overall cost. Especially with parts the rarely fail.

And as for you oxidation example. If you would take apart the column, clean the switch contacts. Charge the customer.

Now a week or year goes by, and the switch doesn’t work again. Either the contacts are still corroded or a spring broke inside. The customer would expect this to be covered. But since you didn’t replace any parts, there is no warranty. So either the tech or the shop does it for free. Or you loose a customer because they pay for the “same repair” again.

But if you replaced the switch, the odds of it failing again within the warranty period are much lower, because every component is new. And if something does go wrong, both the parts and labour are covered.

Now if you DIY, and don’t value your time. Then go ahead go for it.

Or if it’s an older vehicle and parts are discontinued, it may make sense to try and repair the part.

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jontss t1_j263lz1 wrote

The labor for the column was near zero. Spray WD40 in the column. Fixed for another hundred thousand km.

The switch replacement was literally remove the assembly, unbolt the switch, bolt a new one on. About 5 minutes of extra labor vs replacing with a new one. No way that adds up to $300.

0

danielszajkowski t1_j26o5lp wrote

WD40 is not a contact cleaner.

Diagnosing a problem at a shop is usually at minimum 1hr. Currently the shop rates are about $150/h

Book time on replacing the switch would vary from each make and model. But I would expect it to be no less then 1.0h

Then to take apart the switch, inspect what is wrong. Repair the corrosion. (Which is more then just spraying “wd40”). Test the switch. Verify the repair. Reassemble. Document the repair. I would expect 1.5-2.0 hours.

So your probably just about 4 hours, which is $600 plus taxes. With no one covering any warranty.

There is no way a licensed tech is doing that, if they can just replace the assembly. And have the repair covered for parts and labour.

0

jontss t1_j26uarv wrote

Fair. It worked.

I'll take my $3 worth of repairs over $600 any day (that didn't include labor btw). But you do you.

1

purduephotog t1_j24bm2f wrote

>Government could fix this, but won't because captured capitalism.

This was a sarcastic post, right?

Have you seen the size of these batteries? Have you heard the precautions or watched how they're disassembled?

They're 480V. That's a terrifying voltage, nearly insta-death.

They're massive modules with loads of balance wires.

The 'gubberment' doesn't need to do anything- anyone can build a battery to fit there if there is an advantage for it.

This isn't a gas tank pressed between two plates, or a 'chopper' show where they beat some aluminum and weld it to hold gasoline.

This is a massive piece of critical engineering with extremely fatal consequences.

Frack, Boeing stuffed something in their planes and they caught fire because they didn't do it right.

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FuzzyCrocks t1_j24ixyc wrote

Okay if it's not a battery then it is just a cell.

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dragonbrg95 t1_j24uzl8 wrote

Making the batteries smaller individual containers would absolutely add a lot of weight which is already a massive problem for EVs. One large battery pack acts as a structural component so breaking it up not only means adding additional weight for the additional casings, it also means eliminating battery capacity and also adding brackets to structurally attach them to each other (which is both heavier and weaker than one large casing).

This is also an odd thing to nitpick. Battery cells themselves are modular and different manufacturers are using like cells depending on the origin of those lithium cells. This is not unlike battery packs in things like power tools, those battery packs are just containers around cells like this: https://www.samsungsdi.com/lithium-ion-battery/power-devices/power-tool.html

These 3.6 or 3.7 volt cells are more or less the same across all brands (Dewalt, Milwaukee, Ryobi, etc) and if you wanted to you could open those batteries and replace cells. Similarly, people can and do open up EV battery packs to replace battery cells. So long as you k ow what you are doing when you rewire them and don't kill yourself touching a large capacitor they are repairable and replaceable components.

Are you just as upset that you can't for example, swap brake pads between cars? Or intake manifolds? Or that there are a million variations of a spark plug?

1

toughduck53 t1_j24w7y7 wrote

EV batteries are genuinely terrifying, even experienced industrial electricians get nervous working on them. Not only do you have the insane power potential that could easily kill, but if something does go wrong you have a fire that burns incredibly hot for days that's near impossible to put out.

This is not a government, issue. Yes they're are problems with capitalism but you need to stop blaming all your issues on it. This has nothing to do with greedy corporations, this is actually a real issue with safety.

1

DragoonXNucleon t1_j25xw47 wrote

The government mandates a shit ton of things around gas tanks. They have to be located in a certain way, protected, vented, all sorts of things to ensure that your car isn't a literal bomb... as it used to be before regulations. Just like seat belts were fought by the industry for years.

Yet, with electric, "ehhhh do what you want."

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toughduck53 t1_j25z2k7 wrote

I promise you its not "do what you want" lmao. There's just as many regulations around battery manufacturing.

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PeteA84 t1_j2443nf wrote

To combat waste that'll probably be what happens pretty soon. Currently each manufacturer is racing to make the battery with the largest range at the cheapest cost to get ahead in the market. Once we reach an inflexion point (my guess is 2025) then maintenance will be something customers really focus on.

0

HappyHHoovy t1_j23razh wrote

There are lots of people here making good points about safety but there are many reasons as to why EVs are built the way they are. One of which is just physics.

TLDR: Sorry this isn't short, batteries and stuff aren't easy to ELI5 but I think this works? (Other people feel free to correct if this is bad)

Batteries store a potential energy difference - this is a tiny amount - need lots to get correct energy.

After correct energy is achieved, tiny capacity = no range = stack EVEN MORE batteries.

Wires create resistance - loss in energy = bad. Modular connectors = more wire = bad.

Make pack big single block = less wires = less loss = more range = good

​

First, some battery background. A battery stores energy, for a simplified example: If I hold a bucket of water over my head, with an empty bucket at my feet, there is a potential difference in energy between the two buckets. The water in the top bucket wants to go down to the floor, and I will catch it in the bottom bucket to reuse it/recharge.

This is our full charge, our maximum voltage/difference, when all the energy is ready to move but not yet moving.

I pour the bucket out and all the water is at the bottom bucket and none in the top, the water cannot go down any further and we have no voltage/potential falling energy**.** The time it took for the water to flow down would be our capacity. (very simplified)

​

The energy is very small and we need lots of these together the create the required high voltage 300+V sometimes. (This is wired in series) However, the time it takes to pour this out does not give us that power for very long, we combine that first block so we have many buckets pouring one after the other (this is wired in parallel)

We need these modules to be an exact size of series to get the car to run, and a size of parallel to give our range. Some cars are built like this in the factory, where each module is separate. (For an EV I helped design and build we need nearly 100 individual batteries in series to get the movable energy, but this would give us a range of only a few kilometres so we stack 50 of those 100 battery modules together)

Then we get into physics and materials. Engineers use the modular method to design and build the packs, but this is why they might not be modifiable after they are built.

Electricity is most efficient when it goes short distances, if you have to run a long way you will be out of energy by the time you get to your destination, this is like electrical resistance. When building an efficient car we don't want long distances of cable. If I want to swap my battery I need to make all the modules separate, i then need to run lots of wires to a single point and then have a big High Voltage connector to join them to the other parts of the battery pack and to the entire car. Multiply that by 100x and you have lots of metal in the way of our flowing electricity causing resistance and taking away our power as heat instead of spinning wheels.

EV designers make the packs as much as one piece as possible to stop having connectors and resistance. Also the more parts that move and rub together are just more parts that can fail and need to be replaced. The best part is no part. So combining everything into one solid brick is more reliable, safe, easy to manufacture, and also more electrically efficient. This is one of the many reasons as to why some EVs have so much better range than others with the same size battery on paper.

​

I hope my examples were understandable and somewhat accurate. There is a lot of advanced engineering that goes into making finished products like cars and adding new technology makes it even harder to explain/understand!!!!!

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Loki-L t1_j233nhz wrote

That is actually what is happening in some cases with smaller vehicles.

Gogoro who make electric scooter in Taiwan, have a system where instead of charging your scooter at a charging station you swap out the batteries with fully charged ones.

https://electrek.co/2022/01/12/taiwan-soon-to-have-more-gogoro-electric-scooter-battery-swap-stations-than-gas-stations/

This is possible because these scooters only need two batteries and they are small enough to be liften by a single person without tools or help.

For cars that would not work as well.

Replacing batteries when they can no longer hold a charge in parts would not be too much of a benefit since they would all wear out at about the same rate and it makes more sense to do it all at once rather than come back to the shop every few weeks or months.

Since the batteries are so massive and cars move very fast, making them easier to remove would have some safety effects.

In general EV batteries only need to be swapped out after several years and it needs to be done by a professional and the fact that that professional takes a bit longer is a trade of for the battery staying put where it most of the rest of the time.

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crookedriverguy t1_j23bzi2 wrote

Well, you're overlooking a concept here that *might* work:
Car maker Nio offers battery swaps for customers with a "battery as a service" deal. A swap at designated stations are claimed to take 5 minutes

2

2ByteTheDecker t1_j23sqh9 wrote

That's making a huuuuuuuge presumption about logistics. It would be very expensive to roll out on a scale that would make adoption reasonable.

Tesla Superchargers are barely that widespread and that's a much lower impact solution than swapping our hundreds of pounds of battery cell, and has alternate options like charging at home.

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biggsteve81 t1_j24h5fq wrote

A company called Better Place tried that in Israel. It did not work well. Also, DC Fast charging can work on any EV, while a battery swap will only work on one specific brand of vehicle. Imagine if a Ford could only be refueled at a Ford gas station.

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maowai t1_j24ws26 wrote

I think swappable car batteries work fine in some areas and circumstances, but I don’t think that it will ever take off or be necessary in the US. I own an EV and I do 99.9% of my charging at home. Swapping is less convenient than that, I don’t want to pay a permanent subscription on top of the price of the car. Fast chargers along highways are also far less labor intensive and much more mechanically simple than any sort of human operated or automatic battery swapper.

As soon as you own an EV, you realize how bad and unnecessary of an idea battery swapping seems.

1

Vitztlampaehecatl t1_j262167 wrote

This. Swapping out batteries is possible by default on the vast majority of ebikes, because you take the battery out to charge it. But car batteries are just too big to take out easily.

1

Zakluor t1_j23vg03 wrote

The term "battery" originates as a term for "a collection". In war, a collection of cannons and artillery at a fortress error have been called a battery. In terms of power storage, a battery is a collection of cells. Your 12V lead-acid battery in your average car is a battery of six cells.

We have, over time, changed the meaning from a "collection of cells" to "anything that generates electricity". Thus, an AA, which is itself a single cell, has been referred to as a "battery" for many decades.

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Brusion t1_j23lfbh wrote

A lot of points here, but also noone seems to be mentioning that they don't generally "expire". Most of the time the battery should, and is, out lasting the life of the vehicle.

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Warpedme t1_j23untb wrote

This is simply not true. In fact it's entirely incorrect and false.

All rechargeable batteries have a certain amount of charge cycles before they absolutely have to be replaced because they either can't hold a charge as long or as much of a charge or both.

In fact there is an entire industry developing right now where batteries are first used in EVs because they demand the most cycles and intensity of power delivery. Then those batteries are recycled into home and commercial solar power storage. Eventually they will be harvested for parts and entirely recycled to be remade back into other batteries or other things

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Brusion t1_j23vkgs wrote

I have 300,000 km and no degradation. Even if you have a car that has some degradation, the battery still works. You have been brainwashed. Batteries generally outlast the vehicle. You're wrong.

Also, the fact that they can use batteries after the vehicle is dead is true. This has nothing to do with the fact that the batteries outlast the vehicle.

−6

Warpedme t1_j2417jh wrote

I literally work with a solar company that does EXACTLY what I described in repurposing EV batteries into home solar installs. You are the only brainwashed person here and you have zero idea how batteries work. All batteries have a life cycle, every last one. Batteries are also among the most reused, repurposed and recycled manufactured products in existence today.

The batteries in an EV will only outlast the vehicle if parts stop being made for that vehicle or the EV has so many issues that it costs more to repair than replace. The single most expensive part of an EV is the batteries, as long as the battery is safe and the repairs are not more expensive than replacing the vehicle, they will make the vehicle into an EV of Theseus because it's cheaper than replacing the battery. It's not uncommon to reclaim these batteries from EVs that were totaled in accidents.

Not a word of that changes the fact that ALL batteries have a limited amount of charge cycles before they need to be replaced, rebuilt or recycled. ALL BATTERIES. Every single last one. In fact every single time a battery goes through a charge cycle it holds slightly less of a charge. This is true for your Amazon rechargeable AA batteries just as much as it's true for EVs. It's simply the nature of the technology.

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Brusion t1_j24s0uu wrote

Again, you're still wrong. Yes, they get repurposed after vehicle life ends, but that has nothing to do with this discussion. Batteries are not dying before vehicles rust out and head to the dump. You can downvote all you want, but it doesn't make you right

−3

Warpedme t1_j24upt3 wrote

It's like you didn't even read what I said because it addresses exactly everything in this reply

0

Brusion t1_j24x39o wrote

Yep, I did. And perhaps you missed the first post of this thread. If a vehicle is totaled, then the battery lasted the lifetime of the vehicle. I understand all the simplistic points you made, but the batteries do no go through there usable life cycle in the lifetime of the vehicle. Not a single person I know has had to replace a battery in their vehicle, no have we. You addressed nothing, and are simply going off on a tangent to start an argument.

0

oscarcp t1_j23tzrt wrote

I highly doubt the battery can last 25 years with its full capacity. Please explain :)

3

TheBarMic t1_j23uws4 wrote

So it won't last with the full capacity, but after about 10 to 12 years, the average lifespan of a car, the batteries will still have about 70% capacity left. The batteries themselves are currently estimated to have a 15 to 20 lifespan, hence them "outlasting" the car. In fact, a major recycling path for these batteries once the car is retired is to be used in large scale power storage systems! Or the batteries can be recycled of their lithium and become new batteries.

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permalink_save t1_j244zri wrote

Is the expectation that after 15-20 years we just junk the rest of the car? There's cars on the road now that are way older and emissions aren't great but otherwise run fine. The path to sustainability isn't just power type but not having to remanufacture cars over and over and try to make the existing ones upgradeable. Cars take a lot of resources to make that also has impact. Especially since the body usually holds up it's the engine that wears out on ICE. Can't imagine ICE beating out pure electric.

0

myislanduniverse t1_j24tmzn wrote

> Is the expectation that after 15-20 years we just junk the rest of the car?

Not necessarily; but a traditional internal combustion automobile is going to require replacement of some of its critical systems by this point in order to be drivable as well, and this is generally what's meant by the "service life" of a product. Of course you can extend the usable life of the vehicle by replacing worn out parts, but -- even with regular maintenance -- some of those components just aren't engineered to last that long (they can be, but you're usually sacrificing performance or efficiency for durability).

1

permalink_save t1_j25jzkx wrote

I mean, it's not like the timing chain belt and we throw the car away, things are generally serviceable and if it's a choice of 2k to fix it vs 20k to get a new one, not just cars but things in general, why wouldn't you just fix it? People are way too eager to get a new car when theirs starts fucking up but look at other countries driving cars with like 300k miles on them that we traded as "end of their life" at 120k. We're just being wasteful at that point.

1

myislanduniverse t1_j25x21c wrote

While you're entirely correct, the component you've listed is also an example of one intended to last the "life of the car." People in this thread don't mean something different when they say "life of the car" when they're taking about the battery vs the engine. You can keep both vehicles running for much longer by replacing components that have exceeded their serviceable life.

But an EV battery is intended to last the factory "life of the vehicle" in the same ways (and this could be tautological).

1

s0rce t1_j240f37 wrote

Down cycle into grid attached storage isn't really outlasting the car.

−2

on_ t1_j235iij wrote

In reality they don’t have one big battery. Their big battery is a battery of batteries very similar in form to the ones you put on your toys. All those batteries need to work on unison, and need to have the most similar voltage, capacity and charge discharge cycles. If you could swap those individual cells you would create as many problems as you solve. And accessing them would be difficult because those packs are cramped between sandwiches of cooling layers. But hey, loading your car with batteries like bullets into an A10 plane ammo belt would be cool as F

5

BitScout t1_j23btfe wrote

The big battery packs are not only composed of smaller batteries but often also water cooled. Good luck hooking up hundreds of batteries to plumbing.

5

RelativeMotion1 t1_j244ynl wrote

Some of them are like that. Ford EV batteries (like in the Mach E) can be opened by dealerships, and individual modules (an array of cells) can be replaced. Link with pics.

Less shipping, less waste, less cost.

5

intashu t1_j24igdx wrote

All EV vehicles and hybrids use a battery "pack" that pack is made of groups of individual smaller batteries.

A few things good to know is that each battery alone only puts out a little bit of power somewhere between 3 and 4 volts.. But that's not enough to move a whole car, so you string lots of batteries together and now it's 200, 300, even 400 volts.

Normally these are put together in groups, and you can have multiple groups in a single car battery.

But these batteries are also flammable if they're damaged. Much like a phone or laptop battery... But thoes don't normally move at 60mph, and are just one battery not hundreds together. So they need to be protected..

So you put the batteries inside a armored battery box under the car normally. Lots and lots of batteries in this box means the only way to fix them is to remove the whole box and in many cases, remove the whole group of batteries that have one single dead battery in it. And replace the whole set.. Since they're fused together it can be difficult or impossible to safely and properly replace a single battery cell.

There are lots of comments pointing out scooters in Asia with replaceable batteries... Understand the power demand on a scooter carrying two people is substantially lower than that of moving a modern American car. Modular and removable batteries really are not viable in a car without equiptment to do so, and the COST would be higher.. If a company did make a car with replaceable batteries let's be honest, they would 100% make the batteries a loaner you pay monthly or yearly to use, with the ability to exchange it at locations... But if you didn't pay, your loaner battery presently in the car would stop working. The other issue is that batteries are heavy, and often become structural to the car. To be removable means they can't be secured to the vehicle in the same way, and the car would need to be more reinforced to not require the pack for structural support. It causes a ton of engineering issues that just don't matter to a little scooter. And this is still side stepping that battery packs are liquid cooled, it's not just two little connectors from the battery to the car.

TL;DR often you CAN replace a cell group with a single field battery in it. But it still requires removing the whole battery case from the car usually, so it's expensive. Other ways of doing this would be less SAFE for the vehicle owner for a bunch of reasons. And safety and reliability are prioritized instead.

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DeusRexy t1_j23ltxv wrote

Worked in lithium ion battery manufacturing for awhile, people in comments have already mentioned that there are smaller batteries inside the power pack, but no sizes were really told.

Each battery is different, but each of the small batteries I would say the average is something like a Capri Sun pouch, some are bigger, some are smaller. Also, they are pouches, with layered cathode and anode layers (negative/positive), with separator layers between and an electrolyte slurry inside.

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WhynotstartnoW t1_j26l3kn wrote

>Each battery is different, but each of the small batteries I would say the average is something like a Capri Sun pouch, some are bigger, some are smaller. Also, they are pouches, with layered cathode and anode layers (negative/positive), with separator layers between and an electrolyte slurry inside.

Not in Tesla's, they just stack a bunch of A cell, B cell or D cell sized LiIon batteries in the box.

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FrankDrakman t1_j243vcz wrote

there are many good answers in this thread ,but I haven't seen this point:

More batteries = more connections

My first rule of troubleshooting is "90% of the problems are in the connections". You'd be surprised how many 'dead' TVs and PCs come back to life when the power plug is taken out and re-inserted. Each connection is another point of failure in the system. If you had ten batteries, you'd have ten times the chance of a failure.

And presumably, you'd have the consumer opening the hatch and changing the battery. I can tell you, the engineers in most tech companies would hear "consumer changing the parts" and have a heart attack. It's a recipe for a host of problems.

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S0litaire t1_j24kh2u wrote

It's to do with international regulations around "Fixed" and "Replaceable" battery packs which haven't changed much since Li-ion batteries first were used in devices.

With Fixed the rules about how thick the container the battery is in is a lot less restrictive, Also you don't have to worry too much about sparks and shorts with fixed batteries.

With "removable" batteries you have to have certain thickness of container, space around the pack to insulate it from the rest of the device/vehicle, also access door has to conform to certain standards. As well as precautions to stop sparks and shorting when replacing batteries,. all of which adds weight for not much in return.

BMW did have a "battery replacement concept" :
Where you drive the BMW EV into a bay. The base then open up and a robotic grabber unbolts the battery pack from the bottom of the vehicle and takes it to an underground charging area and another freshly charged "pack" is then installed in it's place.

So you can either buy batteries with the car for an added upfront payment and charge them at home like normal.

Or get a "subscription style" yearly package, where the vehicle is cheaper to buy initially, but you don't "own" the batteries in the car, and the entire battery pack is replaced with a fresh/nearly fresh set of batteries every time you need to recharge.

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professorjaytee t1_j23k39q wrote

I used to drive an electric forklift; we had two at a warehouse where I worked. Under typical heavy use we'd need to swap out the batteries in each forklift every two hours or so. That said, it was one heavy MF of a battery. Better to have two people changing one together, although I could do it by myself.

Not sure how practical that would be for a heavier vehicle, with a typically longer desired battery life (range) and consequently (in total) much heavier batteries.

Charging each forklift battery took eight hours or more, so we couldn't wait for them. Swapping one only took five minutes. We had to keep a number of spare batteries constantly charging on an array of rechargers just to keep both our vehicles constantly working all day long (ten hours). We had five for each. Yep... we had ten rechargers and twelve batteries total for our two forklifts.

Sure, we could have used four smaller batteries instead of one, but then we'd need four rechargers in place of each one. That would've been forty chargers required. If smaller units sped up the charging time by a factor of four, then we'd still need the original ten chargers each.

How that would play out with tens of thousands of cars, and even more thousands of battery units constantly sitting in more thousands of rechargers...? Not well, I think.

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Aururai t1_j23ml4x wrote

Forklifts, at least the older ones generally used lead acid batteries, or a variant, not lithium based. So they are orders of magnitude less energy dense, hence why you would need to swap every 2 hours in a forklift.

I've seen a few warehouses where they had a forklift battery swapping station where there was always one forklift ready for use, so you drive in, grab the charged one and they would swap the batteries on it and get it ready for another person.. but these warehouses had hundreds of forklifts

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professorjaytee t1_j23n1hn wrote

The point is, you need more chargers and battery units than driving units. Smaller batteries may make the issue worse, not better.

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WillingnessSouthern4 t1_j23vq2m wrote

A gas engine will fail well before a car lithium battery. Do you often complain about the difficulties of replacing an engine?

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a2r7g90 t1_j249y9s wrote

It can be swapped cell by cell, car knows which ones are done and which still have capacity. But it's not easy.

-anti theft -they want to see the car again to tell what could be done better, harder it is, more cars will come back because more people will be unable to do it in garage. -its new thing with new hazards

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MrWilliamus t1_j24c4g8 wrote

Because there would be way too much wiring, it would increase the potential points of failure and would make multiplexing systems a nightmare. A battery is supposed to last as long as the vehicle -same principle as your smartphone.

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dontsheeple t1_j24i5k7 wrote

Whenever you find yourself scratching your head wondering why they built it the way they did there is really only one answer, and that is cost. It cost more money.

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ginonofalg OP t1_j24rhva wrote

A key point I've not heard much about is the range/power/weight trade off. There's a lot of dead weight sitting around on driveways for extended periods that isn't needed because you don't always need 300 miles of range (think average journey distances) or you don't need to go from 0-60 in 4 seconds. Wouldn't 'modular' be helpful in those situations?

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Kimorin t1_j25iray wrote

adding on to the other great answers here, packs are made with cells, thousands of cells, arranged in modules... usually the modules are wired in parallel with series connection within the module... to reach the voltage and amperage needed...

you can absolutely swap out modules or even cells if you want, but the cost of doing so is pretty high, usually its easier and cheaper to just swap out whole pack due to the labor cost involved... the swapped out pack can be disassembled at factory and remanufactured into refurbished packs with all the checks and validations needed.

swapping out individual modules and cells comes with the issue of cell imbalance... have you heard of people telling you to not mix new and old batteries in your TV remote? kinda the same thing here but on a larger scale... mixing in new cells with older cells could cause voltage imbalances between the cells due to new cells being able to discharge/charge faster than older cells and also take in or output more power than older cells. this could cause problems, like aging the other modules faster than it would otherwise and/or cause decrease in range.

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mynewaccount4567 t1_j25qpge wrote

One point to make is that even with a modular battery design you probably wouldn’t want to make short term battery changes to save weight for less range of not needed. The batteries are a lot of the cars weight and a lot of systems in the car are designed for a specific weight. It would be a lot harder to design a suspension system that could handle the weight range of everything from a 40 mile battery with single rider commuter to 350 mile battery with a family of five and luggage in the trunk.

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series_hybrid t1_j26cvk2 wrote

Its the same issue with battery run-time in phones and laptops. If you incorporate a slide-in framework like a cordless drill, it takes up room and the battery has to be a bit smaller, leading to slightly less range.

My newest laptop has the same size screen as m last one, but the last one had a pop-off battery. The new one is slimmer and lighter than the old one but the battery is smaller.

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Vast-Combination4046 t1_j275pg0 wrote

They are sort of, but assembled into packs that are larger and bolted together to maximize space and reduce wiring. If you remove the seats and some covers they are relatively easy to get out most times, but they are still high voltage and can easily harm you if you aren't careful.

There is not much difference between the battery cells and the ones in drill batteries, but if you needed 100 drill batteries to use your car the packaging would take up lot of space, and then you would need more wiring because you have wiring inside the drill batteries and wiring to get the batteries from the receptacle to the rest of the vehicle.

The battery packs last long enough that making them difficult to get out isn't an issue. You can service individual cells or groups of cells, but getting an entire refurbished unit is recommended because if ones going bad you may end up fixing more not long after.

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randomFrenchDeadbeat t1_j2arpms wrote

They DO have lots of smaller ones, assembled together with a water based cooling system.

Some chinese only EV cars also have a detachable battery assembly so they can "charge" in 5 minutes (they swap the whole battery assembly for one that is charged).

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Shape__Shifter t1_j2315u2 wrote

According to Google, if you replace the battery with AA batteries, you'd need 25,000+ batteries... that'll take some time to replace... also the more batteries you have, the more potential failure points you have

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caspy7 t1_j233bp0 wrote

The big batteries are already made up of smaller batteries internally.

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arglarg t1_j2376fo wrote

Ok but you wouldn't connect 25000 AA batteries in series (ok, I would), that limits the failure points a bit.

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givemeyours0ul t1_j23zjvo wrote

Go watch a how it's made on Tesla or Rivian batteries. Connecting them in series/parallel is exactly what they do.

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arglarg t1_j240ram wrote

Yes but not all in series. For 25000 AA batteries that would give you about 37kV, you probably don't want/need so much.

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purduephotog t1_j24coth wrote

>Yes but not all in series. For 25000 AA batteries that would give you about 37kV, you probably don't want/need so much.

Tesla packs are 100Kw.

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hacktheself t1_j232apa wrote

It’s a conscious choice.

Battery swap technologies for electric vehicles existed in the freaking 1890s in Manhattan. China is incentivizing battery swap vehicles now.

Car makers are choosing to not battery swap for $reasons, despite that it would be better four everyone if all that was needed to “recharge” was a 5min visit to an automated garage that swapped batteries.

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bremidon t1_j2378i2 wrote

You need to actually take a deeper look before being quite so confident.

You are semi-correct though: it *is* a conscious choice. You are just completely wrong on the reasons.

Here are the real reasons:

  • We do not have enough batteries. We need every single battery we can make to be in a car, not sitting around somewhere doing nothing.
  • Swapping stations are bulky and expensive. It is *much* more efficient and effective to use the same amount of space and money to make chargers than swapping stations. We are not talking 10 or 20% better, but more like 10 to 20 times better.
  • Your "5 minutes" only works if you compare a single car charging to a single car swapping. Because you cannot have so many swapping stations, you are going to end up with queues, and that will drastically change things up. Even just a 4 car queue is going to put charging and swapping on fairly level ground.
  • There are legal issues surrounding the batteries. If you bought them, then what happens when you get new ones swapped in? What if you deliberately swapped out defective batteries just to get better ones? If you don't own them, how does that work? Who is responsible for the batteries currently in your car?

I want to make clear that none of these things are unsolvable, but they *are* major headwinds. We are having trouble building out just a charger network; waiting for a swapping network would delay things by at least 10 years or more.

Only the first one is guaranteed to be solved, more or less on its own. In 5-10 years we can strike it from the list. The last one is probably the next easiest, but I expect it will take at least 10 years for all the legal difficulties to wind their way through courts.

The middle two are tough, though. As charging times keep coming down and the ability to charge at home keeps increasing, the use case for swapping gets smaller and smaller. Perhaps it will end up being a thing in some bigger cities, but it will probably never be the standard.

Bonus Reason: Because of all of the previous reasons, it is less expensive (and makes the car lighter and safer) to make the batteries part of the structure. So unless someone can quickly solve all those earlier points, the carmakers are going to all gravitate towards swapping being physically impossible. This reduces the use case for creating a swapping system and the whole idea simply collapses in on itself.

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maowai t1_j250g9f wrote

Chargers are also much, much more mechanically simple than some sort of machine that would swap out your 1000lb battery for you. Electrify America already has trouble keeping their chargers working. Imagine how bad it would be if it was machines with 500 moving parts instead.

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hacktheself t1_j23ubhw wrote

you made highly erroneous assumptions.

the claim of 10-20x efficiency for chargers vs swappers is intriguing

a swap station is bulkier and more expensive to build but at the same time is capable of continuously charging more batteries in parallel and testing all the batteries at the same time

additionally if you have five cars queueing for one 5min swap that’s 20min for the last car; if you have five cars queueing for four fast chargers, even if that fast charge is 10min, average wait time per vehicle is longer and that assumes full high speed delivery of fast charge which is dependent on multiple factors

this latter phenomenon is parallel to the walk left-stand right concept commonly used in escalators except statistically speaking standing on both sides moves everyone faster, both in teens of average speed and throughput and increases escalator reliability since the steps aren’t unevenly worn

the final bullet point is a good one, and there are multiple possible answers but a reasonable one is that access to the battery network is subscription based as in you pay a monthly fee for the batteries

additionally against your final point: swappable batteries aren’t structural but the frame around them most assuredly is, just like how the battery box at least should be structural but the batteries themselves cannot be for safety reasons

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ForceOfAHorse t1_j23b7cp wrote

The most important part of this conscious choice is that... Nobody wants that. Most use cases for cars these days are short trip to work-store-home. Nobody needs to swap batteries. People just charge at their destinations.

There are few problems with electric cars that can be solved with upgrading infrastructure, but battery swapping stations are definitely not one of those.

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hacktheself t1_j23r6ya wrote

hi. nobody here. thank you for acknowledging atypical use cases that need to be considered as more typical if EVs are to be utilisable as general replacements for ICE vehicles particularly in less densely populated regions or for longer trips.

not everyone has access to charging infra at destinations. not everyone can charge where they live or work. not all grids can handle the additional base load of EV charging (looking at you, texas).

swappable batteries would also radically lower vehicle and battery fabrication costs, by the way, not to mention eliminate a worry every li-ion device nowadays has that didn’t use to be a worry: what happens when the battery’s lifespan is breached and capacity craters.

0

ForceOfAHorse t1_j23vy65 wrote

> not everyone has access to charging infra at destinations

So there is a big chance you won't have access to battery swapping station also, since it would require even more powerful infrastructure. If there is no electricity there will be no battery swapping station. Or maybe you just want to buy multiple batteries and carry them with you?

> swappable batteries would also radically lower vehicle and battery fabrication costs

How so? Well, maybe if cars were sold without batteries that would of course make sense, but then you'd pay for the batteries anyway at swapping stations. I'd say that it would increase the overall cost, since you'd need more batteries than cars to make sure there is always one waiting for you at the station. But that's just guess game now.

> what happens when the battery’s lifespan is breached and capacity craters.

You go to the mechanic and replace the battery, like any other part of a car that goes faulty :).

Right now, most EV car consumers have access to charging infrastructure and are not doing very long trips all the time. Those who do, just buy petrol cars simply because they are much more convenient for those uses. If the market of home-charged electric cars saturates, then it's time to compete with ICE cars on those long distances. We are not there yet. And we may never get there, who knows? I know that if I were to buy a new car now, I'd go for electric regardless if I could swap my battery or not. It's just that they are expensive now due to high demand.

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maowai t1_j24yi9l wrote

I would need to visit a special place to recharge my car and a person or myself would have to manually remove 1000lbs of battery and replace it with a new one? That sounds like a much, much worse option than just taking 3 seconds to plug it into the charger in my garage. I don’t see how that’s better for anyone, even if you can’t charge at home and need to visit DC fast chargers all the time.

Could I do it both ways? Allow swapping and charging at home? Sure, but is that worth the immense design and engineering trade offs, when home charging + DC fast chargers work fine in almost all cases?

Relying on swapping would also be a big profit center for car companies because they could charge big recurring swap subscriptions. They don’t do it because it’s a bad idea, not just because of money.

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maowai t1_j24z89m wrote

Only non-EV drivers think that swapping is a good or necessary option. The second you’ve lived with an EV for a month or so, you realize how totally inconvenient and unnecessary it would be.

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hacktheself t1_j2511vh wrote

my kona ev with 62k km on the clock in less than two years would disagree with you but i can see your point

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