Mr. Jilani,

Thank you very much for your authoritative, timely, and thorough answer. I absolutely understand.

I do have a question about your response though. It sounds from this passage that an intact "used" battery is not what's prohibited, but rather the harvesting of the cells. - "will prohibit the assembly or reconditioning of lithium-ion batteries using cells removed from used storage batteries and prohibit the sale of a lithium-ion batteries that use cells removed from used storage batteries."

I wouldn't be removing cells, and they were never removed from the original battery. It is a fully intact battery that had been used. - What you said about the hospital batteries is clearly a separate matter. I thought that they might be even safer, and that's what the manufacturer told me was his feeling. (I bought it elsewhere.) And it's also a LifePo4 battery. - BUT, if I had a used, but otherwise authentic and intact UL-certified battery, would this also be a problem? It does not seem so from my reading of that passage.

Thanks again so much for your reply. If you don't have time to respond to my follow-up question, that is no problem at all.

Jeff
Safety never sleeps! I appreciate your questions and helping clarify things.

A used intact UL-certified battery pack retains its certification so long as it not damaged, defective, or tampered with. It should be used in the intended end product it was designed for. Using an intact UL-certified battery pack in an end product that has never been certified does not mean the end product is certified nor would UL Solution agree that it would be safe to do. Most often battery packs have a safety circuit known as the Battery Management System but how it’s designed to mate with the end product varies greatly. In some cases the BMS relies completely on control circuit safety from the end product and doesn’t have full electronic protection. If you were to ask the battery pack maker they likely will tell you the same, to only use the UL Recognized Battery Pack only in the intended UL Listed end product it was designed for.

Also make sure the certification is to the applicable standard. In the case of e-Bikes and the NYC law, the battery pack requires UL 2271 for safety of light electric vehicle batteries.
 
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Firstly, I appreciate you posting publicly, and I know you didn't post with the intention of debating the merits of the test or if they are the right solution for the fire issues we are seeing. But, I think it is very important to get it out into the open. and that is what public forums are for.

I just want to clarify that you're saying that ebike motors catching fire or exploding or shocking people are a significant issue? Do you have data that you can share on that?
I agree that chargers, of course, need some kind of certification since they have mains voltage.
I'm not trying to pick on you, but this focus on the rest of the bike distracts us from the real problem that we are trying to solve. That problem is batteries from low quality vendors catching fire in peoples homes. Until I hear about an ebike motor fire burning down a house, I am unconvinced.

Regarding the IPX4 requirement in 2849 clause 36, does this apply to batteries, and therefore over-ride 2271? I still think that is insufficient for safety critical things like batteries, especially for wet climates or people who wash their bike with a spray nozzle on the hose. Also, perhaps the pass/fail criteria should involve inspecting the inside of the battery case for water. The 1 hour observation period after testing doesn't seem to be stringent enough given that most issues due to water ingress happen over a much longer period (so corrosion has time to occur).
Electric motor have been suspected as the starting incident that leads to lithium battery fire in some cases. In lab environments, non-compliances have occurred specific to motor requirements and tests when certifying to UL 2849. Other parts of the system have an affect whether or not the lithium battery pack has thermal runaway even though it did not originate from the battery.

Regarding standard refinements to any UL safety standard, comments, suggested updates, and new safety science are always welcome. They are consensus based so opinions of other technical experts will discuss and debate the merits of the proposals. https://csds.ul.com/
 
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Most often battery packs have a safety circuit known as the Battery Management System but how it’s designed to mate with the end product varies greatly. In some cases the BMS relies completely on control circuit safety from the end product and doesn’t have full electronic protection.
Could a pack really pass UL2271 if the BMS is reliant on the vehicle to tell it when to open the circuit? Perhaps in some edge case where the pack is non-removeable?
 
Thanks again Mr. Jilani for responding. I was kind of hoping actually that you were going to say that a used and intact UL-certified pack was not acceptable, only because I was thinking of a counter-argument. I just enjoy that kind of devil's advocate questioning.

So, for example, I suppose that even a first-time buyer owns a "used" battery every time they use it after the first time. And, separately, I'd obviously much rather have a used battery from a person who had taken good care of it. If the first-time buyer had their "new" battery, it could be in worse condition than a used one which had been taken care of properly.

The used battery I bought was from a Segway Ninebot. Besides the appropriate UL certification, I was especially impressed with all the extra safety features that were built in. And I got it at a great price!

btw, I'm familiar with a BMS but your explanation was informative.
 
Could a pack really pass UL2271 if the BMS is reliant on the vehicle to tell it when to open the circuit? Perhaps in some edge case where the pack is non-removeable?
Battery packs submitted for formal certification evaluation at the same time the ebike electrical system is submitted can be evaluated to UL 2271 and UL 2849 concurrently.
 
Battery packs submitted for formal certification evaluation at the same time the ebike electrical system is submitted can be evaluated to UL 2271 and UL 2849 concurrently.
That seems like a dangerous loop hole. What i've read indicates that some of these fires have been caused by buying batteries used in other vehicles, perhaps from the used market. I believe every battery needs to have full protections built into it and not rely on the vehicle.
 
That seems like a dangerous loop hole. What i've read indicates that some of these fires have been caused by buying batteries used in other vehicles, perhaps from the used market. I believe every battery needs to have full protections built into it and not rely on the vehicle.
Fire protection is multi-prong approach.

FDNY has given great education that only use the lithium ion batteries designed for the end product.



Full electronic, environmental, and mechanical protection for battery packs is defined in UL 2271. At this time most used batteries have not been safety certified to it.
 
Very interesting thread.

It seems to me that an ebike battery pack is so inherently dangerous that it must also be protected from impact forces because my understanding is that physical damage to a SINGLE cell can set off a massive fire as other cells contribute.

So perhaps a physically-strong shield will be a requirement down the road, not just a cloth or plastic shell. Our Lectric batteries are in a stout aluminum case; would that pass?

As for preventing a massive fire from just a single cell failure, perhaps a potted "pack" will be required, such that a single burning cell cannot ignite its neighbors. AND the individual cells cannot be re-purposed down the road.

This genie is out of the bottle. How to we put it back in?

EDIT: Regarding the disposal of cells, am I correct to assume that a fully-discharged cell is no longer a fire hazard, regardless of damage?
 
@Fire_Safety, the CPSC recalled this device a year after it burned and killed two girls. It was UL 2272 certified and tested.

Do you know how it was accredited as such but still proved dangerous?

 
UL Solutions Market Surveillance department investigate any concerns reported from consumers, regulators, and any other concerned party related to products identified as UL Certified. Market Surveillance actively monitors CPSC for recalls that involve UL Marked products. They open investigations and work with the manufacturers to determine root cause of the identified concern and ensure corrective actions are taken.

While I cannot go into the full details, I can provide that UL Market Surveillance have opened an investigation and are looking into this matter.
 
UL Solutions Market Surveillance department investigate any concerns reported from consumers, regulators, and any other concerned party related to products identified as UL Certified. Market Surveillance actively monitors CPSC for recalls that involve UL Marked products. They open investigations and work with the manufacturers to determine root cause of the identified concern and ensure corrective actions are taken.

While I cannot go into the full details, I can provide that UL Market Surveillance have opened an investigation and are looking into this matter.
Thank you. While it is lamentable that the causes aren't being made public, it is reassuring that whatever happened will inform future UL surveillance efforts.
 
@Fire_Safety, the CPSC recalled this device a year after it burned and killed two girls. It was UL 2272 certified and tested.

Do you know how it was accredited as such but still proved dangerous?

As mentioned in the posts above, UL certification does NOT guarantee safety. There have been multiple incidents with UL certified packs.
To summarize, 2 of the major causes (perhaps the biggest ones) of fires are internal cell faults and water intrusion. UL does not address the first and is quite weak on second.
 
As mentioned in the posts above, UL certification does NOT guarantee safety. There have been multiple incidents with UL certified packs.
To summarize, 2 of the major causes (perhaps the biggest ones) of fires are internal cell faults and water intrusion. UL does not address the first and is quite weak on second.
Then what's the point?

I would have assumed that "UL Certified" means that, while nothing is 100% impossible, the item is made in a factory that uses very high quality standards and it is very unlikely that the battery will fail, assuming it is charged by a UL Certified charger.

Water intrusion is a whole different matter. Perhaps a future certification requires a circuit that senses flooding, and responds by quickly but safely depleting the charge on the battery. My assumption is that a discharged lithium cell won't burn.
 
Then what's the point?

I would have assumed that "UL Certified" means that, while nothing is 100% impossible, the item is made in a factory that uses very high quality standards and it is very unlikely that the battery will fail, assuming it is charged by a UL Certified charger.
Well, it helps reduce the odds of some points of failure - mostly electrical failures with some mechanical checks such as vibration and temperature swings.
UL2271 (the requirement for batteries now in NYC) is more stringent than the other UL battery tests that can be used to get UL 2849 (full bike) certification.
2271 requires the use of all UL approved materials (i.e. - all plastics, wiring, etc.) need to be UL certified (i.e. - long, expensive materials tests and those suppliers paying UL for quarterly factory inspections)
Also, 2271 has a very thorough BMS testing.

One of my worries with UL mandates, such as in NYC, may actually make the problem worse. Firstly, there is the false sense of security, as mentioned previously.
Secondly, there is already rampant disregard of the existing rules (just basic shipping rules and UN 38.3 testing) , you may have heard of container ship fires from mis-labeled batteries - to avoid hazmat fees. And there is a lot of suspected fraud in Chinese testing laboratories.

So, once these un-enforceable laws are put in place, what happens? Well, the legitimate suppliers that can't afford the added costs of redesigning their batteries and the certification and maintenance of the certification leave the market. Who does that leave? The big players and the cheaters. If the big suppliers are too expensive, where will the users get their batteries? Unaccountable online sellers that don't know the rules or don't care.
 
Water intrusion is a whole different matter. Perhaps a future certification requires a circuit that senses flooding, and responds by quickly but safely depleting the charge on the battery. My assumption is that a discharged lithium cell won't burn.
I think the waterproofness requirement should be much higher. Some BMS do have humidity sensors, but all they can really do is prevent charge/discharge.
I do like the idea of discharging a battery if water is detected. It would have to convert that energy to heat, which would take a while to drain the battery without overheating whatever kind of discharge resistor is used. But, perhaps a slow discharge would be ok if the important bits take a while to corrode in water.
 
Most of us (including myself) were happy the federal government transferred the regulatory authority of ebikes from USDOT to the CPSC. Most were concerned about licensing and insurance, although that was never a given. The downside is safety. DOT is a cabinet level department and they do have teeth that bite. The CPSC can take years to remove consumer products.

Sure there are problems with transportation vehicles, but considering the millions that are bought and sold every year, truely dangerous vehicles are really rare. Cars and motorcycles imported into the country are highly regulated for safety. Ebikes? Ebikes are brought into the country exactly the same way bicycles and any other consumer toy. Containers listed in the manifest as consumer bicycles are offloaded and the value is declared. The importers and sellers are tasked with policing themselves. Only after a tragedy happens the government and lawyers get involved.

If we really wanted to put an end to fires and other safety issues, ebikes and bicycles should be treated like the transportation vehicles they are, and the regulatory authority should be transferred to the USDOT. You see cyclists and ebikers everywhere talking about their right to do this or that, the right of access to parks and trails, the right to the roadway. Consumer goods really don't have the same access rights as transportation vehicles. There's a lot of limitations on parkland and roadway infrastructure.

I'm not advocating one thing or the other. I have my opinions, noting them here won't help. The crap is just starting to hit the fan; the government usually under-reacts or over-reacts. I fear an over reaction is coming. Politicians love to virtue signal they care about some safety issue and they legislate with a big hammer. We are still a tiny minority within the cycling community.
 
@Fire_Safety, the CPSC recalled this device a year after it burned and killed two girls. It was UL 2272 certified and tested.

Do you know how it was accredited as such but still proved dangerous?

This is the article that showed up in my feed:
The author calls them bikes throughout the article except in the sentences that are lifted directly from the recall. Sigh
 
This is the article that showed up in my feed:
The author calls them bikes throughout the article except in the sentences that are lifted directly from the recall. Sigh
Lol that is so obviously not an e-bike, much more so than an e-scooter. Bizarre.
 
Lacking any reliable comprehensive listing by the industry, I started one here: https://www.climateaction.center/safety-certifications
Great list that you have started to build utilizing available sources! It would be ideal if the brand who says they are certified provide a web link back to the certification organization who has actually issued it for the electrical system that is being used on their e-bike. For example here is the link to Velotric Discover 1: https://productiq.ulprospector.com/en/profile/4916127/qgns.e525107. There should be a column actually giving this link instead of the marketing literature. I've shared similar feedback with NBDA leadership that brands should provide direct web link to their product certification coming from the certifiers. It's required by OSHA to have the product listing available.
 
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