I've built a 2.2 KWh pack and spent weeks preparing for the build and did that in my own house in a spot right next to a door just in case I f'd up. Which I didn't, but I was fully prepared for that. You should never do something like this in an apartment building, any more than you would start a metal welding shop or a chemical plant in your living room. The risks are not compatible with shared accommodation.
There could even be a reasonable harm reduction argument that providing proper parts, tooling and documentation would actually reduce the risk. I could see reality going either way on this.
But in any case, arguments from safety should be directed and focused on actual risks. We have laws and building regulations for this reason. As you say, you wouldn't start a melding shop in your living room, but we don't ban anyone from just buying a welding machine.
Seriously: on the scale of 1 to 10 for risky things you could do I think DIY e-bike battery repair should rank higher than parachute jumping.
Finally, the degree of access required by the NY law is broadly summarized as "same level that an OEM would/does provide to dealers or authorized repairers". E-bike manufacturers could easily (and quite reasonably, based on safety concerns) limit that to whole battery packs (because for exactly the safety reasons you noted, basically no repair shop is going to want to do cell level tinkering).
NYC has had over a dozen e-bike related fire deaths year to date, almost entirely killing bystanders. One guy was modifying battery packs in his kitchen, ran out the front door with his arms on fire and his whole family burned to death. A shop in Chinatown was letting dozens of customers charger their batteries overnight in the store and the fire killed tenants upstairs.
So we obviously need right to repair on electronics, but people questioning if we need carve outs for things like battery packs are not Unabomber luddites.
I have some home power tools that use lithium battery packs and they are extremely rugged and overpackaged for safety reasons compared to what I see on these e-bikes. That may be another avenue of regulation is simple minimum standards to thermal runaway resistance and containment in consumer grade lithium battery packs.
And this bit even has nothing to do with right to repair! People will do stupid shit that puts innocent bystanders at risk. That's just life. We should put into place measures that disincentivize that sort of behavior, of course. But giving companies a pass to make hermetically-sealed, unrepairable garbage is not how to do that. Ensuring that customers have detailed documentation and access to affordable, well-made parts so they have the ability and understanding of how to safely do repairs would be a good start.
Either occasionally sets something ablaze unprovoked.
(As much as I hate this as a city dweller, the compromise solution may be simply to ban work on certain types of batteries in multi-tenant buildings and dense residential areas - making it so you effectively need to own a home outside of the city, with a plot of land, to do this. Or perhaps just enforce existing rules better, because I bet that the potentially dangerous activities are already not legal to perform in a regular flat.)
From casual review, it appears that the greatest risk for fire in households remains: cooking equipment, heating equipment, smoking, and inadequate electrical wiring (extensions cords, overdrawn circuits, etc.).
This leaves off other majors like kids with matches, candles, flammable liquids, etc.
Note: This is not to say that LiIon batteries are safe and beyond reproach. The Toronto fire service had 29 battery-related fires in 2022, up from 11 in 2021. This compares vs. 254 "cooking equipment" fires, 158 "open flames / smokers" fires, and 77 "electrical distribution" fires (2019 figures). This suggests lithium ion batteries are a source of domestic fires, but not a major one (~2% of causes).
I wish. I've installed distribution panels and gas gear and none of that comes close to working on a sizeable Lithium Ion pack in terms of risk.
If you don't believe me that is something I can not help but there are other commenters in this thread who back that up, surely the people that actually did this stuff have some relevant experience?
The stats are what they are because of the relative distribution of e-bikes vs gas stoves and such. What should worry you is that the number of e-bikes is still relatively low vs the number of gas stoves.
As for sharing the document, I'd love to but there is no email address visible in your profile, could you supply one please?
As for the statement, as a professional I do tend to believe other professionals. Ultimately the statistics don't lie: lithium ion related fires are a minority of current household causes. To your point, that may change over time particularly where larger installations (e-bikes, solar system batteries) are involved. I'll pitch that the regulatory regime is more than capable of catching up and enforcing change if the degree of risk starts to go up. We already see fire departments commenting on it, so it won't be long before we start seeing guidelines and restrictions on battery sizes within homes.
I haven't published it yet, and will probably do so in the near future so if you read HN regularly you'll see it sooner or later.
Edit: sent! should be in your inbox, happy reading.
I'm not an outlier either. Most of us carry at least one fragile lithium polymer battery on our person at all times.
I understand that larger packs like those on my bicycle are more energetic, but I'm still not convinced that it is more dangerous than something as mundane as the grill on my patio, and the stats seem to back this up.
The point is, though, that both are pretty safe as long as some standard safety protocols are followed. Should you be allowed to spot weld 18650s on your kitchen counter? no. But you also shouldn't be building experimental grills in your living room either, or playing with gasoline.
Battery fires are horrible, and we should be regulated to protect our neighbors from them just as we regulate other electrical devices, explosives, flammable or noxious chemicals, and home wiring. That does not mean that we should allow private companies to dictate how we use or repair the products they've sold us, even though it could absolutely include legislation to forbid us from experimenting with certain batteries under certain circumstances or without certain licensing.
How much of that is due to tech being relatively new?
Gas has some impressive failure modes too; in fact, every now and then I hear in national news about a residential apartment building having to be torn down after being structurally damaged beyond repair by a gas explosion in on of the flats. That's on top of fires and carbon monoxide poisoning. Gas is relatable in its ubiquity and danger, in ways lithium ions aren't yet.
> If you don't recognize that fact then maybe I should send you my safety notes regarding lithium ion battery packs?
I'd actually love to read those. I am personally afraid to play with lithium ion batteries, though a little less than I am playing with propane tanks. Maybe your notes would help me recalibrate. My mail should be in my profile.
None. The power density + basic chemistry and the way in which packs are manufactured are pretty much set. Without a change in any of those we won't see any major safety improvements. My hope is on a safer basic chemistry becoming mandated.
> Gas has some impressive failure modes too; in fact, every now and then I hear in national news about a residential apartment building having to be torn down after being structurally damaged beyond repair by a gas explosion in on of the flats. That's on top of fires and carbon monoxide poisoning. Gas is relatable in its ubiquity and danger, in ways lithium ions aren't yet.
Yes. True. But: yet.
> I'd actually love to read those. I am personally afraid to play with lithium ion batteries, though a little less than I am playing with propane tanks. Maybe your notes would help me recalibrate. My mail should be in my profile.
Ok, will mail this to you right away.
edit: sent.
I don't think there's anything in my house that is as dangerous as a large lithium battery and that's before counting that hoverboards and ebikes that do nothing but put stress on them unlike say a laptop that just sits on a desk.
That's heavily dependent on jurisdiction. In many places you can do your own electrical work without any kind of license (you can pull a permit by simply acknowledging that you are responsible for the work), and the inspection does not adequately cover all the safety issues that could arise.
For minor -- but still potentially dangerous -- things like replacing an outlet or light switch (or, hell, even a mains-connected light fixture), you don't need to do any of that.
> I don't think there's anything in my house that is as dangerous as a large lithium battery
For some reason we accept that many of us have, either in our basement or in a closet, one or more devices that continuously set a fossil fuel on fire in order to heat our homes, heat water, or dry clothing. Many of us even have a device that exposes that fire to the open air in order to cook food. Those devices do have some impressive safety features (well, except for the gas stove, oof), but they also have some pretty impressive failure modes. Not to mention how bad it is for your health to be inhaling the particles a gas stove spews into the air, even with an exhaust fan.
I'm not pointing this out in order to claim that lithium-based batteries are safe or are no big deal. But we accept all sorts of risk in our homes already, and batteries don't strike me as meaningfully different.
Same for electricity to a lesser extent.
As for electronics, if batteries are becoming such a problem that we end up comparing things to gas stoves, I'd vote for regulations mandating standardized, interchangeable, interoperable battery packs. That is, isolate the directly dangerous bit - batteries and charging circuits - and make those work like propane tanks or gas stoves, while everything else in the device should be end-user tinkerable.