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>Have a metal container nearby to drop them into for transport outdoors.

Before doing that, try watching some experiments with fireproof containers specifically designed for these fires, to have an idea how quick and violent this can be, and how bad most of these containers are at preventing it from going from 0 to inferno or to a toxic cloud suffocating you in seconds. This might or might not help you plan for the worst case, or better yet forget about doing DIY battery pack repairs at all.




What do people do in factories?

I'm skeptical of the idea that some repairs are meant to be performed only by "experts" and that nobody should ever try to learn how to make them. It fuels an industry of people charging hundreds or thousands of dollars per repair to install cheap parts, and it's part of the reason our society throws so much stuff away.

Sure lithium ion packs are dangerous, but there is a manufacturing process that: welds cells together to make banks, and that sometimes produces a runaway reaction inside the cells. Given that that's the case, it should be entirely possible to do that safely in a controlled environment inside of a garage.

This is the same attitude that informs our decision not to repair garage door springs. Or more relevantly the same attitude that tells us to just use whatever async library du jour exists but never to learn about the internals of that library. "Don't worry about what's under the hood, that's dangerous stuff" says the dealer's mechanic.


> What do people do in factories?

Ventilation. Compartmentalization. Controlled processes with early warnings. Proper tools. Quality control. Active fire suppression. Not doing that at home with your wife, kids, and your dog.

Sure, if you know what you're doing, can deal with thermal runaway, and can trust your work afterwards, nobody stops you from doing it. I've done it myself (never tried anything larger than a e-bike battery though). Just keep in mind that you're working with a firebomb that deceptively looks like an electronic device.


To add on to this, for most things the failure condition is that the thing doesn't work. Here the failure condition is a very high energy reaction and should be given the proper respect vis a vis safety.


> I'm skeptical of the idea that some repairs are meant to be performed only by "experts" and that nobody should ever try to learn how to make them.

That is a very dangerous point of view. Many things really are too dangerous and require too much expertise for you to do. That's how and why expertise exists - it's required to accomplish certain tasks. Not everything - not nearly everything - can be done by amatuers.

It's dangerous to you and also to people around you. The flaming lithium ion cell can kill lots of other people, or leave them in horrible pain and permanently disfigured with burns, or destroy lifetimes of memory and property.

What will you tell them? 'I thought I could do it'? Why did you try when everyone told you it was too dangerous? '...'

> there is a manufacturing process that: welds cells together to make banks, and that sometimes produces a runaway reaction inside the cells. Given that that's the case, it should be entirely possible to do that safely in a controlled environment inside of a garage.

Not unless you have millions of dollars invested in design (by experts trained and experienced in designing such facilities), equipment, and construction for your garage. And it's not near any neighbors - they don't put those factories in residential neighborhoods.


There are a few points to make here:

1) You need to understand how things work culturally in a country/region. SE Asia in particular does not have the same concept of mandated safety like in the US or the EU. Which makes things easy.

2) People need to stop using "domain expertise" to gate-keep other people from doing something. Yeah, batteries can be dangerous, but that does not mean you need a highly qualified and expensive person to do something trivial, like welding batteries together. If we would have gone down this path, not Intel/Apple/Google would have been born because Fairchild semiconductor had the expertise, IBM was making personal computers and everyone used Yahoo or AltaVista for search, so what would people without experience achieve, right?

When there are no alternatives or they are more expensive than DYI, DYI will always win in places like this. Do you think in Indonesia people have thousands of dollars to buy batteries like they do in other regions?


Computer boards might burn but it's usually just a nuisance. Not so much for high energy batteries...


This is not as big of problem there as it might be in other places. Here, a video of how fuel is transported in other parts of the world (popped randomly on my feed): https://vm.tiktok.com/ZGePEvYU5/. It gets the job done, everything else matters very little to not at all.


Dead people, or living people with serious burns and lifelong disfigurement, or property loss - that "matters very little to not at all"?

If those things don't matter, what does? Batteries?


In a lot of cultures people would rather die trying to save their house. And in many places, for example, people would rather die trying to get their luggage from an airplane in flames thn just running for their lives.

My point being that you should not see everything through “western” eyes where life is valued more over psysical possesions.

And to answer your question: yes, cheaper batteries matter more in Indonesia than “safe” batteries. And I am pretty sure the same holds for pretty much all of SE Asia.


The talking point for every evil is to try paint any moral value as arbitrary and/or 'western'. It's transparently ridiculous on a rational level, and furthers real evil, real harm to real people.

If you find yourself on that side of the debate, on that path, you've lost your way; you've followed the wrong people.


If you actually think commercially available battery packs are being produced in super high tech, super safe, quality-controlled factories by experts, you should try disassembling one.

You do not need millions of dollars of equipment to solder battery cells together. You probably need “expert” training, meaning, like, watching a YouTube video. This stuff is not complicated.


> You do not need millions of dollars of equipment to solder battery cells together.

I have disassembled several. They're all welded, not soldered.

Soldering will damage the cell. Improper welding will poke holes in the cell.

It's not rocket science but as your own comment proves, basic research is required as well as some practice welding it a safe location.


I didn’t know soldering vs welding could damage cells, thanks for that! The battery packs I’ve built are all made from cells that have threaded terminal posts, because I don’t have a laser welder (which as I understand it is the tool that gets used for this most often).

I stand by my point though, because a laser welder is not particularly expensive or exotic equipment, you can safely operate one in a garage, and you can learn to use one effectively with a little bit of practice.

Attitudes like “IT’S DANGEROUS DON’T EVEN TRY IT” are silly, and lead to people having unwarranted fear about really basic, easy-to-understand technology.


Not an ideal analogy. A better analogy is "would you hire an electrician to do task XYZ?" Nothing stopping you from learning enough to do amateur electrician work -- but at a certain point, the risk to reward ratio becomes poor for most people and not a good investment. At a certain point, you're doing it to sate your curiosity -- not an invalid motivation by any means, but it's not necessarily driven by practicality.


You say that, but it sure was nice, last year when my dryer kept popping the breaker, for me to be able to easily track down that the electrician that replaced my panel ~8 years ago had (a) used the wrong breaker for the dryer, (b) used a physically damaged breaker, and (c) improperly torqued one of the legs leading to the dryer.

Learning DYI home maintenance is not for everyone, but I sure have enjoyed it. Being comfortable with so many aspects of my house is something I really like.


Breakers were design to be installed by the average Joe, as are drier legs. The failure mechanism of an improperly installed breaker is that it doesn't work properly, or it gracefully melts in a metal box which is required by law/code to handle that exact case of graceful melting and small plastic fires.

The tools and technique required for dealing with stack of little fire bombs, that explode if poked, bent, or overheated, sometimes at a much later date, while sitting in your garage/living room, has a much more serious failure mechanism. And, more than that, most DIY battery packs I've seen involve lack of funds and Aliexpress cells. In the RC hobby community, everyone knows that you store DIY battery packs, especially those made with cheap Aliexpress cells, somewhere where they're free to spontaneously combust without consequence.

Battery packs are scary. People who understand that have better outcomes [1] than people who don't [2] (tbf, these are Lipo)

[1] https://www.reddit.com/r/fpv/comments/fb1u4d/thanks_reddit_y...

[2] https://www.reddit.com/r/fpv/comments/l1hegi/psa_dont_leave_...


Why yes, I do all my own electrical. Has saved me thousands and I am more careful about many parts of the process.


When there’s actually dangerous stuff under the hood, maybe we should worry about it though. If piercing a cell with a screwdriver is going to cause a fire, and a runaway chain reaction could burn down your garage, maybe we should have a way to give mandatory training on how to handle things safely before you’re allowed to play under the hood.


Why is the cost greater than the benefit?


Because humans are bad at statistics, and don’t want to waste money on hypotheticals. “It’ll never happen to me.” So you can skimp on the cost of safety training.


'under the hood' is relative...

Most vehicles are Skateboard platform anyway; I feel like you'd already have to be in at least a semi-specialized shop to even get to where you can safely FAFO with the pack...

And frankly if a normal person manages to just 'get one' and put it in their garage well I don't know what to say aside from 'sometimes natural selection has factors'...


I’d rather we be able to teach people so they’re safe when they experience the FO part of thermal runaway. Hey, I really needed that bucket of sand.

But I don’t control what other people are doing, so, like you said, natural selection. The problem comes when that garage is adjacent to the neighbors garage, and it catches from there, that we do need to control what other people are doing.


Also, what do people do in RVs in the desert?


What people should do is not have flammable batteries in a vehicle unless the whole system, the entire RV or EV, has been designed by experts. I built custom designed safe solar starlink campers as whole systems and make physics simulations and do extensive tests. That is how you prevent most battery fire in a car or off-grid tiny house in a desert.


Ok how about a gas powered RV, a highschool chemistry teacher, and one of his former students, Jesse. I think that's enough expertise.


Do you perform your own dentistry?


Don’t you? When there’s something wrong in your mouth, do you look in the mirror, use your tongue on it, use a toothbrush or floss or toothpick on the problem before going to see the dentist? Or do you feel pain in your mouth and magically you’re at the dentist without doing any of the above?


I don't bust out the drill or try to apply putty for a temporary tooth.

That is to say, yes, I can confidently exchange batteries (clean my teeth). I'm not confident in modifying those batteries with a welder/soldering iron.

If I clean my teeth and they still hurt you bet I'm going to the dentist.


For people who do this, it's more like changing batteries, than modifying them. You only put the batteries into the slots and attach metal wires to the ends - isn't that a lot like changing batteries already? The device which attaches the wires is simple to use: you press it against the connection, press the foot switch and it makes a little spark and now the wire is attached. If you know what you are doing, building a battery pack out of pre-fabricated cells is not scary.


Then what are they welding in the OP?


I don't see any pictures of welding happening in the OP. I do see a battery pack constructed with the usual spot-welded metal strips. The spot welder is the machine that you press against the connection, press the switch and it goes zap and you have a connection. It isn't especially dangerous, as far as I know. It uses a low-voltage high-current pulse to melt and fuse the metal only at the contact points.


Errors that may lead to a thermal runaway: Accidentally shorting a cell. Putting the cell in backwards. Putting a highly charged cell with discarded cells (or vica versa). Using a damaged cell. Any of these can happen rather easily, with potentially disastrous consequences to life and property.


Many things are dangerous. Use caution and have a backup plan (keep the area non-flammable and keep a bucket of sand nearby) and you'll be fine.


> Many things are dangerous.

That's not a rational response. Everything is dangerous. The issue is how dangerous they are.


Yes, sometimes, when it’s not convenient to utilize infrastructure where I am.

So far I have become adept at removing and replacing my own crown, including heavily modifying when needed, filling if they aren’t too deep (or temporary fillings if they are deep) and one extraction when I was at sea and had no better choice.

I don’t recommend it if it’s not necessary, but for those who may find themselves in that situation there is a book called “where there is no dentist” that outlines most common procedures and tool use. It’s worth learning if you’re likely to be away from “civilization “. Also “where there is no doctor “ can be a lifesaver.


You extracted your own tooth!? Woah. Speaking as someone who has seen people evacuated from Antarctica for dental issues, I'd like to read a blog post or something about that.


Of course, in such a case , you’ve likely waited (as I had) until the tooth is really bad. Despite antibiotics.

I think because of the infection it was quite loose, and prying a little with the elevator was all it took to get it to where it could pull it out with my fingers. If I had not had dental tools, it might have been much harder.

The pain is already really bad, yanking it out really wasn’t much worse than the steady state and once the nerves were severed it was instant reduction in discomfort.

Half a bottle of gin made it easier. The hard part was having to wait until the sea conditions were good enough that I felt like I could safely be numb-faced drunk.


It's not the same thing because I don't have training to be a dentist, but I do have training and skills and knowledge for a variety of non-dentist mechanical, electrical, and electronic things. So this is a specious argument. Where does it end? Do I not do any work myself ever? Or are there things we can all agree some people are capable of doing?

I think the gatekeeping around all of this stuff from people is frankly kind of ridiculous. It's not like the battery repairmen are doing asbestos abatement naked in their living rooms while their families are watching TV. But people are treating it like the same thing.


> I do have training and skills and knowledge for a variety of non-dentist mechanical, electrical, and electronic things.

A fundamental of expertise is knowing the terrain, what you can and can't do safely and reliably. A fundamental of knowledge is becoming aware of far more that you don't know; only in ignorance do we imagine there is little outside our personal boundaries.

Highly experienced professionals will tell me, 'I don't know how to do that, you should talk to ...', and will refuse to even venture advice. My doctor tells me to talk to a specialist. Naive, immature amatuers assure me they can do anything, and can diagnose and treat my medical condition via social media.


Capability is fine but also goes hand in hand with risk. Working on lipo/li-ion cells is risky which is usually why such work is not zoned for residential areas. How would your skills and training translate into something a neighbor or inspector can understand? Would you resent them for questioning your non-dentist abilities? Is someone with no formal training but years of practical knowledge working on devices enough?

It seems like the questions from my end bend back toward proving yourself when a situation breaks, not when it works, which is what sometimes happens when you do work yourself. Have you heard the parable of the nuclear boy scout, David Hahn?


Do trained dentists perform their own dentistry?


Touche.


> I'm skeptical of the idea that some repairs are meant to be performed only by "experts"

If you're skeptical of this very banal notion than you are likely not qualified to be doing whatever work you're doing. Yes, tons of technology is needlessly complicated and the salesmen and their compatriots in the "no user serviceable parts inside" sticker division have spent a lot of time and effort to convince people that the inside of electronic devices is sacrosanct; however that has led to an IMHO dangerous notion that every instance of someone saying "hey, you really shouldn't take this apart on your home bench" is regarded with suspicion, or some notion of "they just want you to buy a new one!" and not that, sometimes things break and if they're designed well, they may well have a failure mode that prevents a much worse failure mode.

And it might be expertise that's the dividing line, but it could just as easily be a matter of the material itself: that sometimes, what's in there is pretty fucking dangerous actually and shouldn't be messed with by just any old guy, even a technical guy, who has a YouTube tutorial. It might be that the parts inside failed for a reason and replacing them, while it makes whatever thing work again, might not actually be a great idea depending on why the original ones failed and that if you don't know the answer to that question, blindly putting them back might be setting you up for something disastrous.

I'm 100% a believer in the right to repair, but I do not mean for that always to be myself. On the rare occasion I take something apart with lithium cells inside (which I avoid at all costs!), I handle them like live grenades and either re-connect them to whatever managing circuitry or, if whatever it is is beyond fixing, disposing of them safely. I don't do this because I don't understand them: I know intimately how they work. I do this because I understand them and respect the danger they pose, not unlike firearms or the parts of my car that I know I don't know enough and am not qualified to fix.

Being intelligent is, IMO, oftentimes more about knowing what you don't know and respecting that than knowing what you know.

And, as an aside just because it's related to this point I've articulated: do not take apart lithium batteries in an apartment. I don't give a shit what your qualifications are or how good your risk assessment might be, you do not have the right to take into your hands the safety of yourself and at the same time, every other person currently occupying the structure you inhabit. That is just not your risk to accept, full stop. You are not an island and all the high minded libertarian nonsense you can muster cannot get around the fact that if you make a mistake, no matter how benign in the moment, you could damn well set other people's homes on fire with zero warning for them.


The flip-side of this is that there are so many activities that people do all the time that carry risk. Plenty of them are not really necessary, and create some risk for other people, and yet they are perfectly acceptable.

A good analogy is the use of candles. They are pointless and fundamentally dangerous, but some people like them. People who like them even think they are calming, which is a very bad reaction to an open flame from a risk-assessment point-of view.

If i knew my neighbour liked candles, i would hope that they are being safe and accept that they have a right to take socially-acceptable amounts of risk, not berate them on the internet.

I don't see how repairing battery-containing electronics is any different. Both are unnecessary, and both could turn a small mistake into a fire.

So, I'm quite happy replacing my own phone battery with reasonable precautions, but no, friend, you may not charge your sketchy e-bike in my hallway.

The level of risk that is acceptable is socially defined, and far from the black-and-white view that some people seem to have.


> So, I'm quite happy replacing my own phone battery with reasonable precautions, but no, friend, you may not charge your sketchy e-bike in my hallway.

Having myself witnessed a cell phone's battery go up when it was nicked during a removal, I'll take the candle a thousand times over one of those. But you know what you know.

Personally I just wouldn't fuck with re-manufactured batteries at all. Batteries should be new, from licensed factories, and they should be recycled in a way akin to car batteries so we don't lose all the lithium inside that's still perfectly good for another go-round in a new battery.


Yeah, i know the risk, that was my point. Given the difference in frequency (say, ~every day vs. ~once a year) and level of attention, the risk to others is at least comparable.

Given how popular DIY phone battery replacement is, you'd expect there to be at least a few incidents reported if it was a major risk, but I just don't see them. On the other hand london fire brigade reports 200 candle fires a year...


> Being intelligent is, IMO, oftentimes more about knowing what you don't know and respecting that than knowing what you know.

Someone once said 'INT is knowing how to make an Atomic bomb. WIS is knowing the implications of actual use'


> if you make a mistake

or if the battery is defective, or the power goes out and you're stuck in the dark, or ...


I design big custom battery packs in car trailers or shipping containers for storing them outside of infrastructure. If the battery catches fire you can drag the trailer or shipping containers further away to let it burn out. Of course it gets harder to drag them away after a few minutes of fire when the axles and wheels start to melt.

The point is to never put Lithium-ion batteries inside buildings, especially not put them inside heavy (metal) boxes bolted to the building.


> The point is to never put Lithium-ion batteries inside buildings

Missing word?

Because I have dozens of 'em inside this building right now...


> never put Lithium-ion batteries inside buildings

No EVs in garages or multi-storey car parks?


You will have to do some research to find out what the new laws in the making and fire department procedures say about garages and multi-story car parks in 2024.

A quick review by me just now suggests the government regulations still have not yet caught up with the new reality in the US and EU:

EV's and large batteries inside buildings are not yet forbidden but probably will be soon.

Fire departments choose to evacuate a building with EV fires (and other industrial fires) and just let it burn out [2].

Fire departments only quench a fire by sudden rapid cooling if possible, for example by drowning [1] the entire Li-ion fire in a basin. Taking the oxygen away is not the goal.

[1] https://www.ctif.org/sites/default/files/2023-03/Putting%20o...

I design neighbourhood batteries as two shipping containers underground. In the bottom container the batteries with multiple infrared camera's looking at all battery sides and also with redundant temperature sensors. The top shipping container will deliver 60.000 liter of water into the bottom container in seconds. Testing such a setup would make for a hot and cool spectacular Mythbusters episode.

[2] https://www.youtube.com/watch?v=MT1QTPEZoHY


EV's and large batteries inside buildings are not yet forbidden but probably will be soon.

I'd like to see a reference for that, the closest I can find is this NFPA bulletin calling for updating fire protection and electrical standards for parking garages, nothing suggesting a ban.

https://www.nfpa.org/news-blogs-and-articles/blogs/2022/11/2...

https://risklogic.com/evolving-fire-safety-recommendations-f...



The conclusion is very encouraging!

> The affected Megapacks failed safely despite total loss.


> Testing such a setup would ...

You've tested it, right?


I wish, it'll cost a million dollars or more to test at this scale and it would still be one data point. Instead I simulated these systems to test the physics.

But please, come help me do this test in real life, it will be fun!


Are you representing these devices to others as safe, with safety mechanisms? That is, are you selling or even giving them to people?

I hope only you are at risk from these devices (and I hope you are safe too, but that's your choice). Untested technology can't be depended on. As a rule I don't believe anything works unless I see it with my own eyes - if I swap in a new patch cable, I ping something. Safety equipment for mortal risks is on a different level.


Sounds like a sound design to me. If he gets sued at least he can argue he did everything reasonable to prevent and quench a battery fire. That's how gen 4 nuclear power stations are designed to cool the core in the event of a loss of coolant incident. The other way is to use LiFePo chemistry which doesn't ignite like LiIon but has half the capacity.


> Sounds like a sound design to me. If he gets sued at least he can argue he did everything reasonable to prevent and quench a battery fire. That's how gen 4 nuclear power stations are designed to cool the core in the event of a loss of coolant incident.

"Sounds like a sound design" isn't sufficient engineering; doing everything reasonable would include testing or using an existing tested design; and nuclear power station designs certainly are tested.


You can sell tickets to the events like it's 1930


> EV's and large batteries inside buildings are not yet forbidden but probably will be soon.

Really? That would more than inconvenience millions of people who already have such things. Seems most unlikely to me. Here in Norway we have about half a million EVs many of which are parked in private garages overnight and in multistorey car parks during the day. I can't recall a single incident where the battery either caused or exacerbated a problem.


> forget about doing DIY battery pack repairs at all.

Yah, some things it's best to not learn the hard way.

But if you're intent on doing it, to it outside on a concrete slab.


P.S. I do anything that involves fumes or dust outside, such as painting, solvents, etc.


>Before doing that, try watching some experiments with fireproof containers specifically designed for these fires

I watched a bunch of those videos on YouTube when I was in the market for one and ended up not buying any. The ones that were fully sealed just exploded and the ones that were vented shot 3 foot tall flames and showers of sparks out of the vents igniting everything on the ground around the container. Better to just charge the bike outside on pavement or concrete away from anything flammable.




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