If unattended, does a hoverboard catch fire in a forest?
Very bloody likely.
Half a million hoverboard users should hotfoot it to the hardware's makers and get a replacement, lest they go up in flames. The US Consumer Product Safety Commission issued recall notices against 10 manufacturers and retailers for 501,300 self-balancing scooters aka hoverboards. The lithium-ion batteries powering the gizmos …
The link suggests "powdered graphite" as a suppressant. I had no idea that powdered graphite could be used to fight a fire, get it dispersed in the room and a small fire could become a big bang?
Just goes to show that you learn something every day. (And El Reg has a good track record in this.)
Water is absolutely the correct thing to use to fight a li-ion battery fire.
The cells currently burning cannot feasibly be stopped. However cells are usually in blocks of many cells. Cooling them down will prevent fire/failure from spreading to the neighbouring cells.
A li-ion battery fire is not an electrical fire, for which water will do nothing, or an oil fire, which water will spread. Cooling it down with water is 100% the correct course of action.
I put an axe through a fairly large li-ion pack at the weekend. One cell immediately went up. Within 3 minutes or so, every cell in the pack had gone. Nothing can stop that initial cell, but water would have prevented the (much larger, and much longer) fire from occurring.
These are Li-ion cells, i.e., salts of Lithium in solution. There is no metallic Lithium anywhere in or near those batteries. While the other chemicals involved are pretty volatile, what you get in a battery fire is not a "metal fire" but a pretty much self-sustaining, rapid exothermic reaction of the components of the battery. Since it is self-sustaining (i.e., does not need external oxidisers), pouring water onto the ongoing mess will not add significantly to the reaction. As noted by others already, it will cool down the mess and thereby reduce the total amount of damage.
It's sort of built in because deep down inside every board knows it's both a phony (not really hovering, is it) and an overpriced crappy novelty without any real world use. Most of them somehow manage to cope with that and function. But if they have that type of rider ... well, you see what happens.
There's also the small problem that, in the UK at least, there's almost nowhere you can legally use them. They are officially considered as motorised transport, so can't be used on the pavement (pedestrian sidewalk for the USians) but don't have any of the required lights etc. which would allow them to be used on a public road. That pretty much restricts them to your garden/driveway.
Legs yes, no mention of feet!
Haven't all rechargeable batteries had over temp cut outs/fuses in them for decades?
Definitely anyone buying one in the UK is for sure a CHAV.
Is that really a term started in eighties from the London MET police, being short for 'Council House And Violent'?
Surely you mean "sideways-motorised-skateboard"? I'm with you though - not really sure what niche they fill, and without a catchy (and blatantly lying) name, I'm not sure they would have caught on to the extent they have. Which fortunately isn't very much.
To be fair to Swagway, they label it themselves as "smart balancing electric skateboard". The hoverboard term is only used by media.
Now, the guy in the video. Seems to me that the motor drives are engaging, but not with the result of making the wheels spin, which probably starts overheating the coils in the drives, resulting in fire which eventually might have triggered overheating batteries. Seems like a situation the electronics have no safeguard for, which is bad design.
Also, apparently, you have to calibrate the board before use. Did he do this?
The vid seems like a mix of very bad design, and incompetent use.
As for needing lights for public use as stated in this forum, apparently it has left and right indicators...
I'm in no way a fan of these things, but when stupidity results in in the thing burning up, the onus is on the manufacturer and a very crap design/QA department.
"42 cases of overheating batteries that caused burns to necks, legs, and arms, or severe property damage to 16 customers"
16 people suffered 42 incidents of injury and/or damage?
Are we talking about the sort of person who just cant take a hint, despite having hoverboards explode under them twice already?
"42 cases of burns etc.
16 cases of severe property damage.
Somewhere between 42 and 58 total incidents.
That wasn't too hard to work out, was it?"
Evidently it was. What it actually says is that there were 42 reported incidents of overheating, 16 of which caused either burns or severe property damage.
"From 500k devices? Sounds pretty good odds to me."
From 267k devices; that was just the incidents for Swagway .There were 99 in total between all manufacturers, although Swagway appear to be the only ones that have actually injured anyone.
suffered 42 incidents of injury and/or damage
From 500k devices? Sounds pretty good odds to me. And far better odds than a Hotpoint tumble dryer, where about a million faulty devices (under varying brands) have caused something around 2,000 fires in the UK.
Mind you, I'd imagine that the hoverboard figures would be dramatically worse if they included the hospital attendances from people falling off them.
With the proper electronics, Li chemistry batteries are not a problem. Then we travel to China, land of the quick buck where every penny is precious and every corner is cut. As an engineer, I can't tell if some of this stuff is compromised to save a little bit of change or if it's just gross incompetence. I've worked with plenty of people (management types) that know just enough tech to be dangerous, yet insist on being part of the design group.
Anytime some form of power, whether it's petrol, hydrogen or electricity, is concentrated, the design of the system needs to be focused on safety. I found a supplier of Li battery monitoring/charging circuits that sells them at £3ea for small quantities and they are in China. They even sent me a schematic to review and I find that they used a valid approach to the design. I've never had a Li battery fail catastrophically with the proper electronics.
With the price they charge for these toys, another £1 (in quantity) to ensure they don't burn down a house isn't going to tip the profitability balance.
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