Print

Please login or register.
1 Hour 1 Day 1 Week 1 Month Forever
Login with username, password and session length

[dragdeler]

Swapping battery packs is not a feasible engineering goal.

I must get some of that stuff, must be some killer izm.


You're telling us with such high confidence that they could not injection mold this?

Spoiler (click to show/hide)

Stamp out correctly sized bus bars from brass that clip in there (without any soldering like I had to do) and can double as springs.

Put a little contact gel on the spring side of things.

Do some really reliable clip in contact at the other end of the battery, the end that is not facing the user during insertion.

And put in as many killswitches as there are parallel series, to prevent arcing during swaps. Could totally trigger that mechanically, from the same clip in system that ensures that the battery stays in place, to make it absolutely safe.


And that is just going by my stupid methods, somewhat at scale but still to be somewhat assembled by tiny chinese hands. Tesla is sticking to these 18650 you see in the picture and tho there are benefits...

Why not those cells? Sacrifice a bit of range, gain a bit of safety, much bigger cells, way fewer contact points to maintain.

Spoiler (click to show/hide)

Dude are we really going to argue we can't slide little boxes into drawers?

[Lord Shonus]

Sure, you can design something like that. If, that is, you're willing to accept a significant decrease in energy density, a larger vehicle, and a much greater vulnerability of the battery to damage. Not to mention that your proposed solution (changing out all those individual battery cells - a Tesla battery has over seven thousand of the things) would be slow enough to change out that you probably aren't actually gaining anything compared to current fast charging. Would probably be slower, even.


The only situation where battery swapping would be desirable is if it was a single-unit pulled and replaced in a few minutes. Maybe you could accept 10 minutes as an occasional thing. Any longer, and you're better off with current fast-charging tech.

[dragdeler]

Realistically you are not letting any enduser INTO the plastic, that's a big nono... Assuming we stick to those tiny 18650 that, yes you need thousands for an EV... It gets kind of ridiculous sure... But what the enduser would be swapping out would be bigger fractions of the whole, inside of which many singular cells would allready be connected never to be touched by anybody but certified maintenance personel (void warranty etc to avoid electrocutions).

Let me do some quick math, 7000 18650-type cells is roughly 350 kg of loose battery cells, if memory servers right, EV batteries are about half a ton, let's assume that with the space and materials wasted to make it maintainable, ours hits 600kg. Swappable packs must remain safe, tesla operates at about 350-400 volt... Anything that is to be remotely safe is not to exceeed 50v, so individual packs, could not make up for an entire series. Yes you would totally make the plugs idiotsafe so it takes effort to short the poles but still probably better not to get into super high voltages for individual packs. Series would be constituted of 8 to 10 packs. The amount of series you put in parallel is up to you kinda**, but you got to reach that base voltage... But you are stuck to multiples of 8-10. 600KG divided into 20 battery packs that 30kg per box that is to be put inside a drawer, which might be a bit heavy, make it 40 swappable boxes and you have 15kg per pack, more ideal. 40 times 15kg out, 40 times 15kg in, on the whole you will have moved 1,2 tons by lifting 15 kg 80 times...

The issue is starting to become more apparant, is it a pipedream though? I would vehemently argue not so. There is the asterisk thing ** first and foremost: don't need all that reach? Don't take all that weight. HOW ABOUT THEM APPLES HUH?! Then: an ablebodied man on his own can still be faster than a charging station (else: jobs? yay ??). You wouldn't need to allways swap them, you could also mostly charge them and swap them rarely... For example, only when batteries get old, because these puppies if you open them all up would actually enable trained maintenance personnel ( ) to swap out the deadest cells, rearrange the rest according to it's capacity, and really breathe in some new life into it by adding 1-2kg of fresh cells, instead of throwing half a ton to the curb!! And here is the kicker: you can absolutely standardize those slide in drawers, and have machines removes 40 packs at once, and put in 40 perfectly balanced packs.

[Mathel]

Removing a battery automatically isn't really that much of a problem. You make is a solid block and place it in the undercarriage. The undercarriage has a big door for removing the battery, but it can only be opened with a special key.

You make battery changing stations. They have specific pads, on which you park. Then a door in the pad opens up, and a robot housed within opens the door in your car and swaps you battery.
Then the door closes up and you leave.

This could reasonably be done in 2 minutes.

But then the swapping station would have to charge those batteries back up and store charged batteries for swapping.

The charging of batteries would have to be done far away enough from the battery storage, that if one of the batteries being charged combusts, it will not light the whole storage on fire. In fact, they should be separated enough, that if one of them combusts, it doesn't light any of the others on fire. These things are expensive and burn really hot.

The charging is going to be a problem. If we assume 1000 customers/day and 20minutes of charging time, we get around 14 batteries being charged at any given time on average.
But the customers will not be coming in on a schedule. So you will have to have bit more capacity for charging than that, and you will need to have storage for batteries that are waiting to get charged.

You will also have to have a storage for batteries with bad segments, waiting for repair. This storage should have the same precautions as the charging stations.


So can it be done? Certainly.
But the buy-in cost will be significantly greater than for a gas station, and it will require more workers and more space than a gas station designed for the same amount of cars. Which will project into the cost of having a battery replaced, because you will be paying not just for the charge, but for the time of the machines and people involved.

I expect that the price of having your probably good battery replaced by a certainly good one might cost 3 to 5 times as much as having it just charged up.

[Enemy post]

Part of it is that the game is deliberately targeting a very specific kind of nerdery that will understand a lot of military and midcentury political things before starting, so the game doesn't bother to explain them.

I think this part might actually be the opposite for me. I’m interested in the history, but the fact it’s a video game means what I know will unpredictably become useless whenever game logic takes over, like in Space Marine divisions, or trying to figure out if the AI is smart enough to make the navy and amphibious invasions important.

[dragdeler]

Yes actually distributing them in any meaningful capacity, beyond the kind of tirechanging quick servicestations who are allready fairly well equipped, probably could never be quick to take off... If they were ubiquitous, little swapping contraptions as you described would be the kind of thing the more boutique gas stations would invest in just for customer satisfaction, or because they have other concerns and means of spreading the load (gigantic gas stations with 20 plus pumps), or because the company selling battery subscription makes it a paletable deal to them or whatever. TBF the whole idea is less about filling them up...

Even in my own usecase I don't see myself swapping depleted cells for charged cells, eventhough I won't reach anyway near the loading speeds you have for cars, and in total there are only 7 such plastic boxes as pictured to swap out. There is a degree of danger involved into fiddling around with that, do it too often and you get careless... what I will absolutely do, is run routine health checks and swap around cells between individual plastic boxes every 4-6 months. It's easy to do, measure volts of all series (which is allready being done by the bms constantly), those that start deviating too much, measure individual cells swap weak for good cells until the volts are more or less equal again. Omitting the possibly multiple charging processes that might have to be done to get good measurements, the actual manipulation is work for less than 2 hours. 2000watthour battery for bicycle, less than 900€ in parts and cells, tho tbf an embarrassing amount of workhours to cut PEHD into jigsaw and solder brass springs together... And it gets to live inside an aluminium box between the two tires of the real axle, so the shape and watertightness are much less of an issue for me to be fair.

But you know the fact that individual cells would in theory be exchangable, the fact that you can partition the battery and swap around parts yourself, as a person about to invest into an expensive new car (or in my case, wanting to build an ebike), I would value that very much over a half a ton battery that comes in one block and needs a beam hoist or a crane or such, and other special tools (or in the case of bicycle comparison, 400-500watthour readymade battery with propriety sockets, for half a grand or so).

[Lord Shonus]

Now here's the question. If you were given the choice between two otherwise identical cars, one that has that kind of battery and can go 200 miles on a charge, and one that can go 300, which would you pick?

[dragdeler]

I'm so incredibly tired of hearing boomers yap about the reach, it's like dad, you're not going to drive from here to barcelona in one night, it's not the 80's anymore.


Meaning I know what buying decisions the target demographic for new cars would make... And sigh... even if you're a big commuter and you do 300-400-500 miles daily... As long as the car is full in the morning and you got like 20-30% more distance for unforseen stuff... Like chillout folks what are they so anxious about? It's allways the same, look at shiny dangling key, and then a few years down the line: "oh you might as well buy a new one sir", and then there is whining and complaining but never do people question their earlier choices that set them up that route.

[ChairmanPoo]

That depends on your job

[McTraveller]

I think people just like to complain.

Or worse, they're the people like the lady suing Reese's parent company because the Hallowe'en pumpkin Reese's cups don't have eyes and mouths cut out like on the package.  Like, why is your response to sue the company instead of be like "oh bummer, that was $5 I can't get back, I'll just eat them anyway and not buy any more."

[Criptfeind]

Knowing nothing about this story the way you described it makes me thing that this lady is a hero. Food companys shouldn't use false pictures to advertise their products. Sure, 5 dollars is laughable to sue over yeah, but defraud everyone in the country 5 dollars and now you've got a multi billion dollar scam. Companies should be held to account for what they do and the lies they use to advertise.

[hector13]

… but if they had eyes and mouths cut out, you’d presumably get less product to consume?

[McTraveller]

Knowing nothing about this story the way you described it makes me thing that this lady is a hero. Food companys shouldn't use false pictures to advertise their products. Sure, 5 dollars is laughable to sue over yeah, but defraud everyone in the country 5 dollars and now you've got a multi billion dollar scam. Companies should be held to account for what they do and the lies they use to advertise.

Wait what, has there ever been a food company that puts actual photos of actual food on their packaging?  I can't believe there's anyone in society that would be surprised that the product doesn't look like the image on the tin, and claim it's fraud. Disappointing, sure... but fraud?

Spoiler: image (click to show/hide)

I mean, the packaging on this one clearly says (in typical small print) "Decorating suggestion" next to the picture.  Most of the other packaging images you can find online or in the store don't show the cutout at all.  Now there are dozens of different packages, and the images I can find don't show the backs, so some look like they do have cutouts without disclaimer language on the front at least.

Of course from that image if you look at the package it looks like modeling clay filled with sand anyway, so is that false advertising too?

Apparently the lawyer from the case is "known for" lawsuits against food companies. Also apparently, the suit was filed by "a Florida woman".

See Here for one of many links to the story.

I dunno, yeah I guess maybe there are some things that are misleading, but if you've ever had a Reese's pumpkin before in your life, none of which ever had cutouts, would you have an expectation that there is now a cutout?  Is this really a slippery slope like the lawyer argues in the quoted story? Or is it trying to get a $5M payday because people are trying to win the lawsuit lottery?

I mean I'm all for consumer protections but this... feels like a waste (even if it is somewhat entertaining).

[Criptfeind]

Wait what, has there ever been a food company that puts actual photos of actual food on their packaging?

Yes.

I can't believe there's anyone in society that would be surprised that the product doesn't look like the image on the tin, and claim it's fraud.

No one said they are surprised.

'Minor' shitty advertising deceptions are obviously common, no one is surprised by that. Is a stupid pumpkin smile the biggest deal in the world? No, and neither are the last hundred lies Hershey's assuredly told. But that doesn't make it right, and it deserves some pushback at times. Companies do this sorta thing because they know that most people most of the time are going to just let it slide, but they do deserved to be called out on it occasionally.

Disappointing, sure... but fraud?

You not thinking something is important doesn't change what it is.

Now, fraud requires intention to deceive. (maybe I'm not a food lawyer lol) So obviously Hershey is going to claim there was no intention to deceive, and that might even be true. But I mean, they clearly put it on the packaging to make it more appealing to people purchasing it. What about it makes people likely to buy it? Do you think they expected people to actually take a tiny knife and carve out a pumpkin smile following the "clear" (lol) "decorating suggestion" (lol). Obviously not, so it's either to make people think that's what the product looks like or... I guess just thinking the idea of a pumpkin smile that doesn't exist will make people happier with their product? Honestly, that second one sounds the most likely to me, but I think even if it's not a intentional deception and just some marketing designer thinking it looks nicer on the package and not caring what the actual product looks like it's still sorta shitty deceptive advertising.

Of course from that image if you look at the package it looks like modeling clay filled with sand anyway, so is that false advertising too?

No I think that's just how Reese's is.

I dunno, yeah I guess maybe there are some things that are misleading, but if you've ever had a Reese's pumpkin before in your life, none of which ever had cutouts, would you have an expectation that there is now a cutout?

A: Companies make different little holiday changes to their candy all the time, so it really isn't that far fetched an assumption that they did something new (shrinkflation away the smile lol) B: Who's ever eaten a Reese pumpkin before and actually put enough thought into it to remember what it looked like a year later?

Is this really a slippery slope like the lawyer argues in the quoted story? Or is it trying to get a $5M payday because people are trying to win the lawsuit lottery?

Por qué no ambos?

[Il Palazzo]

Honestly, whenever I hear about frivolous litigation like that I end up thinking yours is not a serious country.