How dangerous are disconnected bulging batteries?

Question

It is well understood that if you have a device that uses a Lithium-Ion battery, and if the battery starts to bulge, then something is wrong with the battery and you should properly dispose of it by taking it to a battery disposal/recycling center. Improper handling could result in a fire being started by the faulty battery, so it's best to dispose of the device and have it replaced.

However, I am curious when the battery begins to deteriorate and starts to bulge, is it still dangerous when it's removed from the device and set aside? To be clear, none of the metal leads are coming in contact with any metallic, or conductive material, so the circuit is not complete on the battery. It's just sitting on a non-conductive, safe surface.

Context

I bought a piece of hardware yesterday at its only problem is that the battery is bulging. I've taken out the battery and I want to keep it until I can find an OEM replacement, which could take a few weeks to arrive from the distributor.

I want to keep the old battery so that I can compare it against the replacement which, I'm afraid, might be a KIRFy piece of hardware. I'd want to return it and get a refund if that were the case. Keeping the old battery around for a while does have it's purpose.

Answer 1

I don't know, and I suspect there are not any solid numbers that will answer your exact question. If it's bulging there is clearly pressure inside, but the risk is not obvious. However, there is a way to make the battery less dangerous.

The worst that it can do is burst into flames. You can find videos illustrating pretty much the worst that is possible.

So keep the battery in a place where, if that ever occurred, serious consequences would not result. For example, inside a metal box of some kind with no flammable materials nearby. Don't store it in a cardboard box on a shelf full of papers, for example, rather treat it more like a thin vessel filled with gasoline or a container of gunpowder.

By the way, lithium cells are not allowed to be shipped by air in a good many instances, so this kind of thing tends to take longer than you might otherwise expect.

Answer 2

Exactly what are you going to compare to the replacement? Can pictures or numbers or some kind of mock-up be used instead? Unexpected fires are bad.

Bad things can happen <50,000 youtube videos could be linked here> ; the thing might start burning pretty hot and long, and can skitter about while it throws a couple feet of flame.

Is your "safe surface" still safe? Even so re-read your fire insurance and check that it's up to date. Bad things often find a way of getting worse.

Answer 3

On a lithium ion cell that has been overheated or mechanically damaged, self-discharge through internal shortings can be in progress. This can lead to thermal runaway at any time, even if the cell is not used/connected/moved/heated/whatever. Such a thermal runaway will typically annunciate with a self-heating but you are not safe if the cell is dead cold now. This may change within minutes!

Do yourself a favour and keep such a cell in a safe location. A metal case on a non flammable surface will do.

There are few consumer goods that contain materials with the potential to self-ignite from cold temperatures. In fact, chemical fire starter is a safer material than your phones battery. No need to worry unless it is damaged, but if it is ... be careful!

Answer 4

If you have access to electrical tape, carefully tape the contacts to prevent any accidental short circuiting.

Place it in a non-sealed container outdoors, ensuring it cannot be punctured. If it it stored in a sealed container, and the battery starts releasing gases, pressure could build up and cause an explosion.

Also perhaps photograph the battery incase it catches fire before the other one arrives (it shouldn't, but it's better to be cautious), so you can still make a comparison between the old and new batteries.

Answer 5

I feel that there is paranoia about Li batteries. This is the result of the news reports of various fires/explosions attributed to these batteries. However, when you take into consideration the millions of them that are in use, it seems to me that they are very safe.
I would recommend that you put the battery in a metal case, about 10 times the volume of the battery, and place the case in the shaded part of your backyard.
If there is no shade on your backyard, make some by using cinder blocks and a piece of plywood.

Answer 6

Its probably harmless if its stable (not heated, deformed, charged or short circuited). If by some chance it does overheat, be extremely wary of the fumes. Its possible that hydroflouric acid can be produced - this is very nasty even though the immediate effects are not noticable. The risks are low, but its better to be aware.