The FTC already debunked this claim years ago (which the article states). Calling out manufacturer propaganda shouldn't even need to be a thing we have to do...
https://www.ftc.gov/reports/nixing-fix-ftc-report-congress-r...
https://www.ftc.gov/reports/nixing-fix-ftc-report-congress-r...
Apropos: not rare at all to open AAA brand battery packs to find burned out wiring, burned out circuit boards, signs of combustion that somehow didn't go outside of the case. Take no risk with these things, even with the good ones: in case of doubt place in fireproof container and deliver to a recycling station that knows how to handle them safely. If you have no experience with these then do not try to repair a pack because the risks are nothing to be trifled with.
Finally: cheap stuff containing 18650's should be avoided like the plague, if the device is cheap then that means the components are even cheaper. Only use devices that use quality cells, that haven't been recycled and that have only been used within spec.
Your fire insurance policy protects you from monetary loss, but it won't revive you or your companions...
What should they be replaced with? I'm curious to know what alternate chemistry you're proposing for my e-bike battery.
Why do you say this? Non-ebikes can be sub-16 lbs; ebike battery packs can weigh, like, on the order of 50 lbs. Ebike users sometimes need to lift the bikes (up stairs at home, or on/off transit).
Battery pack weight absolutely dominates the design and utility of ebikes; any double-digit percent factor is very relevant (IMO).
A really large e-bike battery is 4kg. Nobody is riding an e-bike with 50 pounds of batteries. Even the battery pack on a Zero FX, an electric motorcycle, is only 42 pounds.
A bigger issue is that batteries are often placed in very bad spots (such as riding high on the rear pannier).
That would be nice, but so far there are no good candidates that have anywhere near the energy density of Li-based cells. As far as I understand it, besides material degradation and overcharge/overdraw, the energy density itself poses a risk. So even if we had that miracle cell chemistry it would be still pose a fire hazard when subjected to mechanical stress. The stored energy has to go somewhere.
More important is that Li-ion cells are no joke, and are not equivalent to ‘AA’ or ‘AAA’ battery formats. You can NCM, NCA, LFP, Cobalt chemistries and blends within - not even accounting for differing mAH and charge/discharge capacities. 18650 is simply a form factor.
Better labeling, specing, regulated and certified repair processes are just a start for solutions as it is currently a Wild West.
However, statements like ‘Li-ion should be replaced ASAP’ do not factor in that… lithium ion as a platform is not going anywhere and has essentially won at least the next half century for 18650 type form factors and applications. Moving away is not a reasonable solution.
Other chemistries are usually indicated by a different designation, such as LiFePO4, LTO and so on.
Yes, you can go into the details of the exact chemistry, the packaging, the manufacturers specs and so on but for bulk DIY purposes this is the reality. The detailed chemistry obviously has some implications for safety but because you will have no idea what is in a pack unless you open it (and plenty of times the cells are unmarked) you just have to assume the worst. That's the safest.
Lithium Ion chemistry is the internal details of the battery. Which denotes the type of lithium ion battery, there is no generic lithium ion battery. It will fall under a certain category (Ex LFP, NMC, NCA).
The same battery you linked on other websites is called out as NMC: https://voltaplex.com/sony-vtc6-18650-battery-us18650vtc6
Sure you can go buy unmarked cells on ebay but any reputable website should list the battery chemistry on their website or have a link to the datasheet. It is no different than buying any other electronic component.
It is very clear to me that there is a vast gulf between DIY and professional application, and for the latter I'm 100% sure that everybody there would be able (and should be able) to make the distinction. The number of hobbyists that can do so is going to be very low.
For maximum cringe, have a look at this youtube video and spot the potential problems:
https://www.youtube.com/watch?v=DAoCK3QNLng
And that's one of the very best.
I've spent a long time in that community, and a golden rule is to never mix cells - even cells of the exact same type because they're often binned to be matched to be even closer in operating capacity. Also, and more relevant here, mixing old and new cells is also a big no no due to changing characteristics during aging and use.
You can't just pop open a battery pack and replace a bad cell. I mean, you can, but if you cause a fire that kills someone, you should go to prison for negligence.
Many manufacturers make this difficult or impossible on purpose, and apparently they also have lobbied to change legislation to continue being able to do this, using battery fires as an excuse to cement their parts and repairs monopoly. It's that simple.
You then want to extend that to the other main parts like the motor or the controllers, so you're not left with a piece of junk when one component fails. Just like for normal bikes.
But if the hoverboard manufacturer had released the proper specs for their batteries and the safety procedures they undoubtedly provide to their employees and service centers. Then maybe the DIYer would have made something safer.
By keeping safety-critical details like the correct battery chemistry to themselves, they actually encourage people to do stupid things. Getting access to these informations is a big part of the right to repair movement.