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Having recently read this question with its answers it seems like I should never ever charge my phone/laptop/tablet unattended. It also seems like I should always be worried about my devices exploding without any reason, and keep them locked in some super-secure bag or safe or something at all times, but that's not how we use our devices.

I have my phone in my pocket, in my hand or against my head all day, and at night, it's charging beside my bed. I'm assuming there's about a billion people doing roughly the same. I also usually have my laptop on the top of my lap, with its battery less than a centimeter from my legs, and I can't be alone there either.

I'd like to quantify this risk with some statistics, to compare it to, say, the risk of dying by falling from a chair (8 people in Sweden in 2014, 8e-7 of population per year) or by bicycle accidents (roughly 25 people per year in Sweden, 2.5e-6 of population per year).

How many people die or get injured by LiPo batteries in phones/laptops/tablets (with the casing on)? How worried should I be?

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    \$\begingroup\$ You misunderstood the answers. The batteries in your phone and other devices are pretty safe because there's been a lot of effort expended to make them safe. Bare cells (sucha as used in RC models) are a different thing and are dangerous and require careful handling (attended charging, safety bag, etc.) \$\endgroup\$
    – JRE
    Apr 27, 2016 at 10:03
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    \$\begingroup\$ In 2002, there were more than 33,000 deaths and 8,000,000 disabling injuries that occurred in the home - I'd be more worried about going home \$\endgroup\$
    – JIm Dearden
    Apr 27, 2016 at 10:04
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    \$\begingroup\$ @JImDearden: Especially when at home there are LiPo batteries being used everywhere... \$\endgroup\$
    – PlasmaHH
    Apr 27, 2016 at 10:27
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    \$\begingroup\$ @PlasmaHH OMG - I must move to the woods immediately where I'll be safe. \$\endgroup\$
    – JIm Dearden
    Apr 27, 2016 at 10:35
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    \$\begingroup\$ I'm voting to close this question as off-topic because it has nothing to do with electronics design. \$\endgroup\$
    – Vladimir Cravero
    Apr 27, 2016 at 11:30

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Overcharging a LiPo will provoke a strong exothermic chemical reaction which can lead to injury and or fire. This is the reason, why LiPios must be monitored while charged, at all times.

Every suitable LiPo charger can monitor each cell of your lithium battery and will cut off at ~4,2V to prevent overcharging. This is good enough in >99,9% of the time. The monitoring circuits are sophisticated, cheap and easy to build. Usually, a comercial bought Lithium batterie with a suitable charger is save. However, technical devices can fail and if so, a fire can start easily if no person is present.

As you've seen in the video, an overcharged LiPo is by no means something like a bomb, but the chemical reaction is stong enough to enlite furniture and by that, lead to a house fire.

To extinguish a lithium fire, you can use a common ABC-extinguisher or sand.
Water is not the ideal extinguisher for Lithium.

There is probably no public statistic to the damage due to LiPo batteries. You can find news and blogs about single individuals damaged by LiPo explosion. But this is rare and kind of overrated. As long as you handle them reasonable and as long as they're not damaged, LiPos are save.

If you have a damaged lithium batterie, discharge it at a low rate ( e.g. 0.1c or below, don't leave the scene!) and give it to the recycling. Don't forget to tape both terminals, so no short circuit can happen.

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  • \$\begingroup\$ One of the answers in the thread referred to in the question points out that industry practice in many cases is to use water, as there is not all that much lithium. \$\endgroup\$
    – Scott Seidman
    Apr 27, 2016 at 12:42
  • \$\begingroup\$ As this thread points out, you're right. Shouldn't be THAT dangerous. But still, water is not the first extinguisher to pick. electronics.stackexchange.com/questions/34501/… \$\endgroup\$
    – jawo
    Apr 27, 2016 at 12:46
  • \$\begingroup\$ batteryuniversity.com/learn/article/safety_concerns_with_li_ion -- according to batteryuniversity, the FAA recommends water or soda for small in-cabin lithium battery fires. I'm no safety expert, but it's possible that warning people away from water extinguishers will prevent trying to extinguish a fire when no other extinguisher is in place. \$\endgroup\$
    – Scott Seidman
    Apr 27, 2016 at 12:50
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    \$\begingroup\$ I already edited my post accordingly. From "Never try to extinguish Lithium with water" to "Water is not the ideal extinguisher for lithium" \$\endgroup\$
    – jawo
    Apr 27, 2016 at 12:51
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    \$\begingroup\$ Grammar-check & spell-check should be integrated into the answer dialog. \$\endgroup\$
    – Robherc KV5ROB
    Apr 27, 2016 at 12:55

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