Woman Suffers 2nd-Degree Burns after Her Fitbit Explodes

Megalith

Megalith

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It seems like everything is at risk of exploding these days. One woman’s Fitbit Flex 2 went bad when it was on her arm and ended up giving her a significant burn, enough that doctors had to extract pieces of it out of her skin. Fitbit has offered her a free replacement device, but I would have tried to get a little more out of it.

Dina Mitchell said she had owned her Fitbit Flex 2 for about two weeks when the fitness tracking device allegedly caught fire on her arm while she was reading a book on Tuesday night. "I was literally just sitting and reading when my Fitbit exploded,” Mitchell told ABC News in an emailed statement on Sunday. "It was either defective or really mad I was sitting still so long… I don’t know. Either way, it burned the heck out of my arm." She said she ripped the device off of her arm as it was still burning and tossed it onto the floor. Mitchell said her doctor had to pick pieces of plastic and rubber out of her arm after the incident.
 
At the end of 2016, FitBit reported 60 million devices sold. 1 exploded. Not a bad ratio, IMO.

Cars catch fire. Hairdryers catch fire. All kinds of kitchen appliances catch fire, and no one cares. Small electronics though? For some reason that's a huge news item.
 
putting cheap lithium batteries up against the skin and this is bound to happen to someone.
You know car batteries do explode and people have gotten injured just for jump starting their car, right?
Most things with electricity have the chance to catch on fire and or explode if something goes wrong.
 
Hypergreatthing said:
putting cheap lithium batteries up against the skin and this is bound to happen to someone.
You know car batteries do explode and people have gotten injured just for jump starting their car, right?
Most things with electricity have the chance to catch on fire and or explode if something goes wrong.
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I don't think FitBit was using cheap batteries...but even GOOD batteries have problems sometimes.
 
The last thing fitbit needs is another recall. I'm just waiting with baited breath for them to remotely detonate my Pebble....
 
Hypergreatthing said:
putting cheap lithium batteries up against the skin and this is bound to happen to someone.
You know car batteries do explode and people have gotten injured just for jump starting their car, right?
Most things with electricity have the chance to catch on fire and or explode if something goes wrong.
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Wwhen a gas powered car catches fire not a second thought about, it's business as usual. But when an electric car catches fire after a huge crash, they feel the need to make a story out of it.
 
M76 said:
Wwhen a gas powered car catches fire not a second thought about, it's business as usual. But when an electric car catches fire after a huge crash, they feel the need to make a story out of it.
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Well gas is explosive if uncontrolled.
Most people think that car batteries can't explode, but they do.
Here's a short video on how to make a 9 volt battery explode. Sure it requires a short, but it doesn't take long:
 
Hypergreatthing said:
Most people think that car batteries can't explode, but they do.
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Heck yeah they do, I was at a gas station once and saw it happen to this lady, explosion was so powerful it warped her fender well on her Pontiac. She escaped unharmed though.
 
Bandalo said:
At the end of 2016, FitBit reported 60 million devices sold. 1 exploded. Not a bad ratio, IMO.

Cars catch fire. Hairdryers catch fire. All kinds of kitchen appliances catch fire, and no one cares. Small electronics though? For some reason that's a huge news item.
Click to expand...

The difference is how they burn.

Most electrical or fuel fires start out as a small flame, not much hotter than a butane lighter. If you catch them early enough, they are easy to put out.

The batteries in small electronics burn in a completely different way, when they catch fire it's more like a road flare or model rocket engine. If you don't have the correct type of extinguisher handy, there is almost no way to put them out. (water doesn't work, smothering doesn't work)
 
Bandalo said:
Cars catch fire. Hairdryers catch fire. All kinds of kitchen appliances catch fire, and no one cares. Small electronics though? For some reason that's a huge news item.
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It's not about small or large electronics. It's about devices that you wear on your skin (or, worse, in your pants) all day long, every day.

A hair dryer is something that you hold in your hand for two minutes two times a month... or in some people's cases for ten minutes once a day. Moreover, the most dangerous parts are not on the nozzle nor the handle. Kitchen appliances will usually not come into direct contact with you for more than a second while you push a button. If you're so unlucky that the device catches fire precisely on the small moment when you're using it, there is usually some separation that allows you to escape unharmed and you are aware that you're activating the device at the time so your senses are focused on it. Of the small percentage that explode, a much smaller percentage causes injuries.

With wearables, they are "on" all day so they can explode at any time when your mind is totally unaware of them. They rest against your flesh in an "on" state every minute of every day. So, when you notice the fire you will usually have suffered physical damage already. Of the small percentage that explode, most will cause injuries... in your pants.
 
Since she wasn't doing her exercising it was just taking matters into its own hands and was just going to burn off the fat. The new AI in beta form.

Trying to remember about early digital watches doing that in the '70's but I don't. Of course we didn't have instant news and interwebs.

I remember electronic stuff having the batteries leak nastiness in a few but never started a fire.
 
sir-gold said:
The difference is how they burn.

Most electrical or fuel fires start out as a small flame, not much hotter than a butane lighter. If you catch them early enough, they are easy to put out.

The batteries in small electronics burn in a completely different way, when they catch fire it's more like a road flare or model rocket engine. If you don't have the correct type of extinguisher handy, there is almost no way to put them out. (water doesn't work, smothering doesn't work)
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True, lithium fires are class D, and they'll burn until their fuel is extinguished, or the internals separate enough that they no longer generate enough heat to continue to react. They still garner an inordinate amount of news time. Example: About a week ago there was a fire 30 minutes north of my house. Started by a small kitchen appliance (toaster oven IIRC), and it burned the house down. All the people got out with smoke inhalation and minor burns. Covered on the local news only, never made national news. In this case, a woman suffered minor burns and the loss of a $90 piece of gear, and here it's front-page news.

lironmiron said:
It's not about small or large electronics. It's about devices that you wear on your skin (or, worse, in your pants) all day long, every day.

A hair dryer is something that you hold in your hand for two minutes two times a month... or in some people's cases for ten minutes once a day. Moreover, the most dangerous parts are not on the nozzle nor the handle. Kitchen appliances will usually not come into direct contact with you for more than a second while you push a button. If you're so unlucky that the device catches fire precisely on the small moment when you're using it, there is usually some separation that allows you to escape unharmed and you are aware that you're activating the device at the time so your senses are focused on it. Of the small percentage that explode, a much smaller percentage causes injuries.

With wearables, they are "on" all day so they can explode at any time when your mind is totally unaware of them. They rest against your flesh in an "on" state every minute of every day. So, when you notice the fire you will usually have suffered physical damage already. Of the small percentage that explode, most will cause injuries... in your pants.
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Well, for a hair dryer, or a curling iron, or kitchen mixer, or whatever, the contact time and time of use isn't a good metric in this case. Yep, you only hold that dryer for 5 minutes a day. But that's also the only 5 minutes a day the thing is turned on. So technically you're exposed to the hazards 100% of the time the device has power, just like a wearable. Plus those small appliances can burn you, electrocute you, explode and shapnel your kitchen, or pinch your fingers in the beaters, etc. A wearable's only mode of injury is catastrophic battery failure.

People die all the time in fires caused by home electronics. Or they're electrocuted to death. Of the VERY VERY few wearable accidents I've heard of, it's all been minor or no injuries.

I'm mainly saying the risk of injury is INCREDIBLY small compared to the risk of injury from any other electronics you deal with every day.
 
All wearables should be designed where if it gets too hot the band pops off almost instantly. That way if it goes off the thing falls off before you get bad burns.
 
tunatime said:
All wearables should be designed where if it gets too hot the band pops off almost instantly. That way if it goes off the thing falls off before you get bad burns.
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I can see it now.. wearable pops off into gas tank opening while somebody is pumping gas and then it catches fire and ends up catching the car on fire and then the pump, and then the whole gas station goes up.
 
cyclone3d said:
I can see it now.. wearable pops off into gas tank opening while somebody is pumping gas and then it catches fire and ends up catching the car on fire and then the pump, and then the whole gas station goes up.
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Would make for a good news article.
 
What people don't understand is that any device that contains a battery can explode. That includes small little button cell alkaline ones as well. The only difference is the amount of energy produced. A small button cell you are unlikely to notice before removing it from the device as the amount of energy it contains is very low. The more energy packed into a smaller package the more energetic the reaction. Lithium batteries pack a ton of energy into a very small package. Anyone who straps or holds any battery powered device should be aware of this basic fact.
 
cyclone3d said:
When was the last time you heard of a device with a coin cell battery catching fire?
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Probably about the same as the 60 million to 1 Fitbit fire.

There are a number of reports of LED kids shoes catching fire, which were power by CR2032 cells, as well as dash cams and other small devices that use coin sized batteries. However, even assuming non were ever reported, they can still catch fire or explode, that does not change.
 
BlueFireIce said:
Probably about the same as the 60 million to 1 Fitbit fire.

There are a number of reports of LED kids shoes catching fire, which were power by CR2032 cells, as well as dash cams and other small devices that use coin sized batteries. However, even assuming non were ever reported, they can still catch fire or explode, that does not change.
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But was it the batteries themselves or a short in the devices that caused those fires? I am guessing it was a dead short.

Unless a coin cell is severely damaged.. as in smashing it just right for the positive and negative poles to make contact, there is absolutely no chance of the battery causing the problem. The insulation layer between positive and negative on coin cell type batteries is quite thick and very hard to short unless done intentionally.

The real problem with the lithium batteries is that they are making everything too small. Because of that it is fairly easy for them to short out. A defect is much more likely to happen as well as that defect to cause actual issues.
 
cyclone3d said:
But was it the batteries themselves or a short in the devices that caused those fires? I am guessing it was a dead short.

Unless a coin cell is severely damaged.. as in smashing it just right for the positive and negative poles to make contact, there is absolutely no chance of the battery causing the problem. The insulation layer between positive and negative on coin cell type batteries is quite thick and very hard to short unless done intentionally.

The real problem with the lithium batteries is that they are making everything too small. Because of that it is fairly easy for them to short out. A defect is much more likely to happen as well as that defect to cause actual issues.
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You can guess all you like, they happen and can happen, that is the nature of batteries. And we don't know what exactly it was in this case either, again, 60 million to 1, or 0.000001% failure rate. Anything, ANYTHING can be dangerous, you have to consider the risk in everything you do, or just never get out of bed.
 
cyclone3d said:
Unless a coin cell is severely damaged.. as in smashing it just right for the positive and negative poles to make contact, there is absolutely no chance of the battery causing the problem. The insulation layer between positive and negative on coin cell type batteries is quite thick and very hard to short unless done intentionally.
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Or unless they have manufacturing defects...
 
Bandalo said:
Or unless they have manufacturing defects...
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That would have to be a pretty bad manufacturing defect in that type of battery for it to short out all by itself.

Have you ever taken apart regular batteries?

The construction of them is pretty fool-proof and very safe.

They are completely different then Lithium batteries.

You can smash them with a hammer or hydraulic press or whatever as much as you want.. and they are generally not going to short out and start a fire. They will just stop working.

Try that with a Lithium battery and see what happens.
 
cyclone3d said:
That would have to be a pretty bad manufacturing defect in that type of battery for it to short out all by itself.

Have you ever taken apart regular batteries?

The construction of them is pretty fool-proof and very safe.

They are completely different then Lithium batteries.

You can smash them with a hammer or hydraulic press or whatever as much as you want.. and they are generally not going to short out and start a fire. They will just stop working.

Try that with a Lithium battery and see what happens.
Click to expand...

They're designed for different things and supply massively different amounts of power at higher voltages. So yes, they are different.

And yes, I've taken classes on battery design, so I've seen the insides of lots of different battery types. Li-Ion batteries are fairly safe. You hear a lot about the accidents because of the energy involved, NOT because of the chances of shorting out. With a typical coin cell (say a CR2032), you have an energy density of ~650milliwatt-hours/cm3. Or something like 240mAh total energy, and only around 3V nominal. More importantly, they have a high internal resistance (around 30 ohms) which means even if they short, you're still looking at a fairly low current, and you'll suck the low-capacity battery dry quickly. So when they DO have manufacturing defects, you just get a dead battery out of the package. But they can heat up and cause damage and fires to surrounding electronics. This also means you can NOT get high currents from these types of cells.

On something like a cell phone battery though, you're looking at 800-3600mAh of total energy depending on the phone. And internal resistance is closer to 40-50mOhm @ 3.6V. When that shorts, you have a much higher peak current, and much higher heat is developed, which leads to breaking down the internal barriers of the battery, which leads to the high energy chemical reaction with the electrolyte.

Also, to be clear, "regular" batteries like the coin-cells we discussed ARE lithium batteries. They're just lithium-manganese, not lithium-polymer or lithium-ion rechargeables.
 
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