I have a defective lithium-ion battery, one that is bulging quite severely, it's about 50% thicker in the middle than at the edge.

While the battery actually still works, I've replaced it as the old one didn't fit inside the device any longer, and the screen was about to come off.

However I can't safely dispose of it just yet, so the question is, will it be safe enough to just leave it unused on a table until I can get around to dispose of it safely, or is it safer to keep it cool/frozen?

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    Your best solution is to put the battery in a fireproof container. A battery like this is a potential fire hazard and should be isolated to prevent property damage in the event it does catch fire. RC folks use fireproof charging bags to protect against these types of situations.
    – bwDraco
    Jul 23, 2016 at 10:38
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    No, don't freeze it. Last thing you need is more crystalisation inside the battery.
    – Bob
    Jul 23, 2016 at 10:47
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    I removed the phone reference as phones are technically off topic for Super User. This condition can affect any pouch LiPo or prismatic Li-ion battery; most thin-and-light laptops use pouch LiPo batteries and can be affected by the same issue, so this question can certainly extend to computer hardware.
    – bwDraco
    Jul 23, 2016 at 12:17
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    When my wife brought home her mangled laptop and high-capacity battery after it was run over by a car (don't ask), I stored the battery in the BBQ grill outside until I could take it to be disposed the next week (in a metal bucket in the back of the pickup). Probably overkill, but LiIon batteries can have spectacular catastrophic failures. Not sure what I would have done if it had exploded in the grill, guess I would have come here asking if the grill was still safe to use for cooking food... :)
    – Johnny
    Jul 23, 2016 at 21:50

6 Answers 6


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I had this happen, and I had to store it till I had time to drop by a designated ewaste centre which specifically accepted lithium ion batteries. (This is important. Throwing potentially inflammable materials in regular trash is bad. Only you can stop fires)

There's likely no need to panic if it's a week or two.

You want to store it for as short a time as possible. For most part, unless you stab it, an unused bloated battery ought to be reasonably safe. Practically you want to leave it somewhere cool and dry - so a fridge isn't the best place. The fridge trick is used for dying batteries in some cases, not dead ones.

I'd suggest taping over the connectors to prevent accidental shorting and just leaving it somewhere non inflammable.

Freezing doesn't sound bad until you realise you need to take it out there's a sudden change in temperature (potentially bad) condensation (see moisture).

It's also worth considering this had happened over a course of weeks or months before it got noticeable - there was some pressure on the screen and I'd assumed it was an air bubble the screen protector, and I'd noticed the bloating entirely by accident, so short of baking (advertantly or otherwise), burning or stabbing your battery, or taking a few months to do it, you probably don't need to massively baby the battery. Just don't charge it (and for once self discharge is fine). A battery not in use is slightly less likely to spontaneously catch fire.

There're a few suggestions I've seen online - like putting the battery in salty water (which sounds like a terrible idea, especially since lithium reacts violently with water, and is a potential source of bloating anyway) or trying to discharge the battery (energy flow could mean heat could mean fire). The MSDS backs this up, suggesting that the electrolyte reacts with water to form HF (which is nasty) and the anode with h2. And many other scary things.

So leave it alone, keep an eye on it, and avoid viking funerals and you should be fine.

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    "and I had to store it till I had time to drop by a designated ewaste centre which specifically accepted lithium ion batteries." Depending on where you live, it might be worth noting that the store you purchased it (or the replacement) from may have an oligation to dispose of it for you, which may be more convenient than doing it yourself. Check your local laws for such a requirement...
    – Jules
    Jul 23, 2016 at 12:56
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    @Jules: Here in New York, any store that sells rechargeable batteries must accept rechargeable batteries for recycling. That includes most drugstores and electronic stores. Any major big-box store like Best Buy or Home Depot will recycle batteries.
    – bwDraco
    Jul 23, 2016 at 13:01
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    Yeah, it is scary. HF in solution is pretty nasty too and I think I'd err on the side of caution. I am rather attached to my vital organs.
    – Journeyman Geek
    Jul 23, 2016 at 23:53
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    @A.Grant: On the subject of charge vs residual energy: there is much more chemical energy available for an explosive failure than the charging level would indicate. The level of charge is based on how much energy the battery can supply under normal discharge. The energy available in a free-oxygen runway reaction is much higher.
    – HardScale
    Jul 24, 2016 at 17:37
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    Having seen the battery recycling facilities in big shops that sell things like mobile phones and laptops I'm more pessimistic than you. They may be legally obliged to accept batteries for recycling but whether they're actually competent to accept damaged ones is another matter.
    – Chris H
    Jul 25, 2016 at 19:14

When I had a bulging Li Ion laptop battery, I stuck it in my barbecue grill outside until I had a chance to take it to hazardous waste disposal.

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    Barbecue grills are used to fire... So long as there aren't any holes in the bottom, this is a good idea.
    – wizzwizz4
    Jul 23, 2016 at 18:43
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    AFAIK almost every grill has holes in the bottom, except maybe those big horizontal barrel smoker things. Charcoal grills have holes and vents top and bottom to control the amount of air venting through and control the heat, but you can at least close these. Many propane grills have holes in the bottom for the grease can. Also note, a common propane grill will have a can of flammable grease attached to the bottom of the grill. Also remember the big tank of propane. Still, this isn't a horrible idea because the battery in the grill won't combust in your house or garage.
    – nexus_2006
    Jul 23, 2016 at 20:41
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    To clarify, I've never seen a charcoal grill with holes under the charcoal, unless the grill has a separate tray for the charcoal to sit in. I've seen plenty of vents, but they're not holes under the coals.
    – barbecue
    Jul 23, 2016 at 21:11
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    Just don't accidentally turn on the BBQ!
    – TLW
    Jul 24, 2016 at 0:34
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    Damn. I'm really disappointed that your profile isn't just full of barbecue-related answers.
    – RJFalconer
    Jul 25, 2016 at 16:10

This is a fire hazard! You need to isolate the battery to reduce the risk of property damage.

RC LiPo battery fire RC LiPo battery fire (source)

  • The battery is internally pressurized with oxygen due to a cell failure. All Li-ion batteries can generate a small amount of free oxygen internally during normal operation, so most batteries are encased in a rigid shell to prevent expansion. However, in the event of failure, a cell can generate enough oxygen to expand dramatically. (You probably remember from chemistry class that oxygen is one part of the fire triangle, so guess what happens if the cell vents and there's a spark or open flame nearby...)

  • Puffing occurs when the battery has suffered metallic lithium plating due to abuse or failure, causing the oxygen to not recombine as intended in the cell chemistry. The metallic lithium reacts with the oxygen to form lithium oxide, but lithium oxide has less oxygen than the normal lithium ion chemistry, causing free oxygen to accumulate inside the battery. This extra oxygen is what causes the battery to expand. Needless to say, this can be a serious fire hazard. More information can be found in this Traxxas forum thread and in this blog post by Matthew Barnson.

  • While this condition is most often encountered by RC enthusiasts who push LiPo batteries to their limits, any pouch LiPo (or even prismatic Li-ion) battery, including the kind used in mobile devices, can suffer this type of failure. If the cell is allowed to vent, a fire could result.

  • The best thing to do is to isolate the battery in a fireproof container. RC enthusiasts often use dedicated fireproof charging bags to prevent fires from causing property damage in the event of battery failure. If you don't have such a container, leaving the battery outside in a metal barrel or similar can reduce the risk of property damage in the event the battery does ignite.

  • While freezing the battery will reduce the expansion (as most gases expand and shrink almost linearly with temperature), it will not reduce the actual amount of free oxygen inside, nor will it fix the underlying problem of metallic lithium plating. In fact, since recharging a Li-ion battery below freezing can cause plating (see Battery University article), storing the battery in very low temperatures may not be a good idea.

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    "leaving the battery outside" Exposed to the elements? Wouldn't that increase the risk of failure? Or do you mean it needs to be covered? That still wouldn't protect against heat or cold, though.
    – jpmc26
    Jul 26, 2016 at 1:50
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    The point is to prevent it from burning down the house.
    – bwDraco
    Jul 26, 2016 at 1:51
  • This is not an answer to the question. OP is already fully aware of the fire hazard.
    – Agent_L
    Jul 26, 2016 at 12:40
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    @Agent_L: I'm rather confused here. Doesn't this address the OP's question on how to safely store the battery?
    – bwDraco
    Jul 26, 2016 at 13:00
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    @bwDraco The only parts of your answer that actually address the question "how to store" is "isolate battery in a fireproof container" and "don't store in a fridge" (the second in quite convoluted way). It's good to mention the hazards but most of your answer is about how and why it can fail catastrophically while the actual solution is merely a side-note.
    – Agent_L
    Jul 26, 2016 at 13:24

I would contact the local fire department (by their local non-emergency number) to see if they have arrangements for dealing with these. Especially if you're away from home. You don't want to leave it on a table in a hotel room. The fire department would definitely want to help you dispose of it safely rather than deal with the resulting fires.

Please don't use emergency phone numbers for non-emergencies like this. Emergency phone operators wouldn't appreciate you taking up a line while somebody in real danger out there could be waiting in line for their call to be taken.
There are non-emergency numbers for fire and police departments that you can google.

  • I agree totally with the edit. I should have thought about specifying the non-emergency number, but I hadn't thought it was necessary. I guess it just shows that if you think something goes without saying, it should be said anyway. Jul 26, 2016 at 22:43

I've had quadcopter batteries do this after mechanical damage. You already know to isolate the battery in a fire-proof container. The most readily-available fireproof container that I've found in the common household is a thick pot with a lid.

Do not put the battery in the freezer. Freezing may cause already-damaged metal components to contract and could cause a short, leading to fire. Freezing is outside the engineered temperature range even for an undamaged battery, leave the battery at ambient temperature. If you can, store the pot with the battery outside yet protected from pets, animals, and children. Don't leave it near wooden or plastic furniture or decks.

Note that a high-capacity Li-ion battery may cut through even a metal pot, so be careful.

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    I would add to this that the pot should not be non-stick. It's hard to set PTFE on fire, but a battery explosion might well do it, and if you do set it on fire, the smoke is toxic.
    – zwol
    Jul 25, 2016 at 23:55

I'm trying to think how I'd deal with this, in a normal 'what do I have around the house that I can use' manner.

I'd do a pile of sand in the garden, and build a wall around it a few feet deep (literally a pile of sand with a hole in the center). I'd pop a old paint can / wheelbarrow/something else that can contain the battery and if it decided to go pop allow me to move it after without some crazy clean up operation.

I guess I'd chuck a plastic sheet loosely over the top to stop it being rained on, but it'd be in no way 'sealed' as to not build up pressure if it decides to go bang.

  • Plastic can be flammable. Probably not the best choice to cover it with.
    – jpmc26
    Jul 26, 2016 at 1:53
  • @jpmc26: If the battery gets hot enough to ignite the plastic sheet, I would think the flammability of the plastic would be the least of one's concerns.
    – supercat
    Jul 26, 2016 at 23:31
  • @supercat I thought the whole point of making a sand fort and putting the battery in a metal container was to handle the case where it has already ignited? I dunno if any of that would work, but it seems introducing the potentially flammable plastic sheet largely defeats the point. ;)
    – jpmc26
    Jul 26, 2016 at 23:40
  • A big sand fort seems like overkill. Just put it in a paint can or other container, and not right next to anything flammable. I agree that a plastic sheet could actually allow the fire to spread outside the can, which is exactly what you don't want.
    – dan1111
    Jul 27, 2016 at 14:26

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