Are alkaline batteries in storage a fire hazard?

mountaindewer

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I read a story today about how a house caught on fire from a loose 9v battery in a junk drawer shorting out on something. They went on about how the 2 terminals are close together and can easily short out on something if loose. But, they even went on to say that AA and AAA batteries can do the same thing, but it's harder to do since their terminals are on opposite ends. They said to keep batteries in original packaging and to tape the batteries contacts if they are exposed. Stuff that should be commonsense.

Now, here's my thing. I keep on average around 200 or so AA and AAA batteries on the big wooden shelf in my closet for power outages. I keep them in their original packages until I need them. Then when I need some, I open the back of the package along the perforated lines in the cardboard that open up like a little door, and I take out what I need. So they stay in their original packages, and I just feed off of the open package until it's empty. And of course, the ones that I haven't opened are still in their package. So everything is in the original package. If I buy like some panasonic alkalines in the 2 packs at the dollar tree, ill buy about 20 or so, and to save space from them only being a 2 pack (a 2 pack of batteries take up as much space as a pack of 8 energizers) i will take the 2 packs apart, and store them in those generic battery boxes that are about the same dimensions as a pack of cigarettes, and holds 4 batteries. When the lid is shut, the batteries are secured and don't move or anything. So long story short, either in these plastic containers or in the 8 or 16 pack original packages that they come in, my AA and AAA batteries are stored securely. AA and AAA are the only 2 sizes i stock up. With those facts in mind that I keep them secured safely, what are the odds of them just up and starting a fire on their own? The article i read said not let them touch while in storage. I think they're referring to the contact points (positive and negative) of the batteries, and not the physical batteries themselves. I know that the positive side of the battery is the whole can of the battery, but it's covered with the wrapper or label of the battery, and that this wrapper and label is non conducting. I think they're referring to the contact points, cause it would be impossible to keep the battery sides from physically touching each other in their packages

A few other "what if" things would be: What if the separator inside the battery "broke down" and the insides suddenly shorted out together internally? Could that start a fire? Or at worse just cause the cell to leak?

What about if the can of the cell rusted and a weak spot formed, allowing the insides to spill out?

I have had a couple Duracell packs leak, and even a pack of Rayovac that leaked. I'm not worried about leaks, those are just a minor annoyance that just involves recycling them and buying another pack. What I'm worried about is a fire erupting.
 
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idleprocess

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9V alkaline batteries are indeed moderately hazardous when stored loose in such a fashion that they might short their terminals against something that could get hot and itself catch fire or transmit heat that starts a fire. But they also have such inherently limited current-delivery characteristics that this is somewhat unlikely.

With cylindrical cells, it is possible to short against adjacent objects, but the combination of circumstances is much less likely because no single flat object or plane can short a cell whose jacket is in good condition. The old Fenix AAA light on my keychain has popped its head in my pocket numerous times, ejecting the cell into the proximity of a shifting mass of varyingly-conductive keys and as best I can tell any shorting that occurred was insignificant - and the NiMH cells I use can deliver more current than alkaline cells.

Storing cells in their packaging such that they maintain consistent orientation reduces the shorting risk to about zero. Same for non-conductive trays, boxes, tubes, etc designed or repurposed for the task of cell storage.

Leakage is the scourge of the modern cheap alkaline cell. Storing them under mechanical stress seems to encourage the process (i.e. in a battery compartment with springs compressing the cell housing), however I've had it happen to cells in storage as well. I've seen clear fluid, discoloration, corrosion, and the formation of a powdery crust but never signs of any sort of energetic reaction from an alkaline leak. The worst I've experienced was storing them in a sealed container (ammo can) for years on end - nearly every cell in that container leaked.
 

Frijid

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The only question you ask that I have a hard time answering is the one about the separator failing and the internal ingredients intermingled with each other. Maybe a build up of gas from the volume of the ingredients suddenly mixing would cause pressure to build up inside the cell, which would trigger the safety vent to open and expell the gases. But even then, none of the ingredients in alkalines are reactive to oxygen, so therefore it wouldn't flame like a lithium does when it vents.

Ponder this while I prepare to tell you a story. Think about all the Walmart, target stores, hardware stores and every other store that houses batteries to sell. If shorting out while in the original packaging was that dangerous, all of said stores would be tinderboxes. I've personally witnessed a kid in a buggy that was parked next to an island in the middle of a Walmart aisle reach, grab, and throw a pack of batteries from the height of the buggy and hit the hard floor. The mom put them back on the shelf. There was no fire reported that night from damaged batteries setting the store on fire. Some poor sap probably bought them later and cussed at whatever brand they were for being junk.

Around 2001 or 2002 when I was in the 6th grade, we were forced to do a science fair project. I wanted to do mine on auto ignition. I figured the only thing I had that could get incredibly hot, but not produce a flame was a shorted out AA battery. I figured I would wrap the cell in some aluminum foil tighted molded around it to produce the short circuit. My idea was to see which common items would ignite from this heat source and which wouldn't. I tried wrapping toilet paper around the cell before I molded the aluminum foil in place, which would hold the item tightly against the cell, thus getting it hot. I used toilet paper, paper towel, cardboard, a dryer sheet, plastic from a shopping bag, cotton, etc. Nothing caught on fire from the heat. About the only excitement I got was a few batteries hissed while they vented and the jacket on some of the batteries got a little deformed, but no fires. I don't think anything even blackened. I tried one or 2 items with a D cell, and even a 9v. Nothing happened. I abandoned the project and moved on. I then did an experiment with plants and how their root take nutrients through them with a set up involving food coloring that won me 3rd place. Moral of the story is, I purposely tried to start a fire with shorted out batteries and couldn't do it.

Look, we all know a 9v battery and steel wool will cause a fire. But a 9v, or any battery in it's case, is well protected. Pissing off a lithium or nimh battery is another thing, but your not talking about them. I honestly think that you're overwhelming your self with nothing. Have your treasure trove of batteries. The worst thats going to happen is you may see a pack with one that has leaked. Hell, ive seen that happen to a brand new pack of duracells on the rack at a rite aid store.
 

WalkIntoTheLight

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For all practical real-world purposes, no, alkalines are not a fire hazard. They're not like lithium-ion batteries, in that they don't catch fire and burn. Even if you short them, their internal resistance is so high that all they do is get warm. They're safe to store just about any way you like. They're awful batteries, since they'll leak, but it's not going to be a fire hazard.

Yeah, 9v batteries can spark a bit if they're shorted, so just don't store them loose in a pail of gasoline and nails and you'll be fine.
 

mountaindewer

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Thanks guys, I feel a lot better about my decision to keep them now. I try to cycle through them so they're not sitting around too long and they stay fresh. I do have some that are about 4 or so years old that I've been feeding off of and they still test at 100 on my zts. Ive always had a stockpile of alkalines, for many years and the only thing that happened was ive had 2 or 3 cells mildly leak, and that's it. No fires or explosions. I think just reading that article set my anxiety off.
 

Frijid

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Have a look at this video: https://youtu.be/sTSQwtwr-Gg

Those are ones that are abused, not ones sitting idle on a shelf, and the worse case scenario is just a mess to clean up. Nothing a fire hazard, other than the abused lithium at the end, but they're different than alkalines.
 

Lynx_Arc

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just don't store batteries of any type in a fashion that would allow a chance of the terminals shorting out across them. I've had a nimh AAA short out in my pocket on change as the light it was in the head unscrewed and the battery fell out. I typically store my alkaleaks in a plastic fishing tackle type box end to end with 9v pointing outwards towards the plastic box so they have nothing to short out on. If you are storing them bare get a piece of tape and tape over the terminals onto the battery itself or leave them in the plastic package. The thing is if there was even a tiny chance of fire the current plastic wrappers they are sold in would be changed to prevent it from happening.
IMO if you have to have that many alkaleaks I would strongly consider investing in a charger and some eneloops to take the place of a lot of batteries and reduce your dependence on alkaleaks. I've all but abandoned alkaleaks from having dozens of them to at most 8-12 of them and investing in Energizer lithiums for super long term backup. With Energizer lithiums you have worry free backup batteries for decades with no worries but again not allowing them to short out on anything.
 
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