Many lights, many many batteries. Storage ideas?

Best, safest, safe enough- all are variable terms with differing opinions on exact definition. Adjacent healthy cells have been known to ignite when a faulty or damaged cell goes into thermal runaway/fire mode. Now imagine 18 times that more. The combined heat might melt an ammo can; at least it will get hot enough to ignite readily combustible items in contact with it. The rubber gasket is long gone by then, the LiIon gasses and the melting plastic fumes from the shot-shell holders making for a lot of really toxic smoke. If that happens- which it probably won’t but it could.

I’d prefer fewer cells stored together with more space between them using a less hazardous separation substance, perhaps in a thicker metal container but definitely kept well away from anything combustible. Other than the cells left in lights I use regularly I’m also a hypocrite; the few extra cells I have right now are stashed together here in my wooden desk drawer with plastic and paper around them. I know we’re crazy about lights and cells but I do wonder what compels some folks here to admittedly have upwards of 20 cells- do you really have a use for them or is it just a ‘pride of ownership’ thing? I’m just wondering aloud, please don’t answer that in reply and derail the thread :wink:

My eventual plan is to make some nice wooden racks for my cells. Yes, wood will burn but it also has an upper rate limit of how fast it will burn, and even when well-charred it still has some structural strength. It’s also a decent thermal insulator when it’s not in any combustion stage. No toxic fumes when burning with wood and it’s a very good electrical insulator too. I guess a couple inches between cells would be enough to slow down adjacent combustion considerably if it did not stop it. An ammo can is likely going to be the outer container but it will be stored in a wooden box lined with an inch of sealed sheetrock. That box will have sturdy well-attached handles which can be used to drag the whole thing away if needed. The cell racks could be stacked with an inch of sheetrock in between either loose or fixed to the bottom of every rack. Not fireproof but it would slow the process down substantially while still offering a means for removing the whole mess from the building quickly. Better than the wooden outer box would be a kid’s small toy metal wagon filled with sand.

When you can’t stop a disaster you do what you can to minimize the damage it can do and you have post-disaster plans in place too. We’re knowledgeable here and pretty careful too (I hope!) so it’s very unlikely any of us will have a problem but it is still possible and we should plan for the possibility.

Phil

Yeah I prefer to plan for the worst and hope for the best. I guess I could spread the batteries between 3 ammo cans to at least minimize thermal runaway…… I wonder what temp these batteries burn at when they go? I know ammo cans are used all the time as small portable camp stoves for winter tents so I know they stand up to heat and flame well. I just don’t know how hot.

I did buy one of those fire proof bags for cash that I had inside a safe. I could buy more of those and use them in conjuction with the ammo cans but that would get a lot more expensive.

If you are worried about the cells being in a protected area (although not the cheapest route to take) then why not get a fireproof safe and use it for the storage of your cells?

Something like this maybe? •Protects for 30 minutes up to 1550°F; UL, ETL verified
http://www.walmart.com/ip/First-Alert-2011F-Fireproof-Security-and-Media-Safe/17432335

Not a bad idea. I actually have 2 fire safes similar to those. I didn’t know if that was a little bit too sealed and would make for a pipe bomb/ pressure type scenario…? Maybe I should empty one of mine out and see if it holds water or how sealed it is pressure wise.

You could always drill a small hole or 2 in one to let pressure escapes and still have probably 95% of the fire proofing there.

I keep cells in all my lights and have lots of spare batteries. From everything I’ve read charging batteries is typically where the danger is and not having them just stored. If storage was a problem then laptops would have the same issue when they’re off the charger; their protection circuit is to prevent overcharging/over-discharge and doesn’t do anything for spontaneous combustion.

That is actually what originally made me put them in an ammo can…… a friend of mine had a laptop battery start on fire. One that was just sitting there, not being charged.

And now that I have more batteries it got me thinking that the can probably wasn’t sufficient.

When a cell vents, the production of gasses is close enough to that of an explosion that a few small holes would do nothing to prevent an over-pressure failure of a smaller container. The volume of gasses might be contained in a strong larger unit which had room to allow for it without bursting, but on opening the container you’d get a face-full of hydrogen fluoride so probably not a good idea. Removal of all but the end of the ammo can gasket on the latch side is my plan (it needs to be left there for the latch to stay closed) I don’t know if that is enough but with the lid having ‘flaps’ extending downward it would hopefully direct some of the venting in a safer direction (downward into the outer container). It would also leave the can able to shed water similar to a house roof but still vulnerable to spray or water ingression if the can were turned over. Which would be a good idea as you could toss a burning can into water and it would enter the can to cool the situation and prevent adjacent cells from joining the fracas. The water would probably ruin all the cells but at that point who cares?

I’m not sure the ‘ideal’ method or container exists for in-home storage of a large number of cells. It would need to protect from heat on both sides (from the outside in case of a house fire so that the cells don’t overheat and add to the problem). It would need to be quickly removable to the outdoors. It would need to direct gas venting in a safe direction while maintaining enough structural integrity to remain movable. And it would need some mechanism to prevent or at least slow down considerably adjacent cell reactions from overheating should any individual cell burn.

Here’s a pic of 20 cells burning Battery U (scroll about 3/5 down to figure 8) which is what initiated my response here. There is danger in one cell going boom, but I wouldn’t want 20 doing it together.

Phil

Is there really any danger of these cells exploding while just sitting around? I can’t recall a single story of something like that happening. I also have mine in a plastic shotgun shell case which prevents them from shorting together and insulates them electrically, but without any outside impetus I can’t see them causing any problems. I should probably add that I don’t have any potentially untrustworthy cells, not even any laptop pulls. Mine are all high quality cells.

So yeah, I buy good cells and just store them in a plastic case, sitting on the shelf next to my lights. I’m quite comfortable with that.

Good point on the ammo can gasket Sawmaster. I have been hooking the latch on mine but not locking it down so it wouldn’t have immense pressure. But removing most of the gasket seems like a better idea.

Just climb into the safe yourself and you’ll then be protected from everything.

I doubt there is any risk with “good” Li-Ion cells stored in 18650 plastic cases not connected to any electronics or drain source, as long as they can not short in any way, and not exposed to high heat sources, or impacts.

A safe? You mean my mile-deep bunker isn’t good enough? :bigsmile: More seriously life always causes your death so there some point where it’s not worth worrying about anymore. A lightning strike may be more likely but I’d rather not have either happen to me. Good cells are “safe” but not perfectly so- nothing is. When your time comes you’re gone so it may not be of that much concern to any given individual. I just see easy ways to greatly reduce this particular small risk and I think they are worth taking the time to do.

Phil

I can’t……. because the batteries are in there…….

:wink:

you could just give them to me if you have too many! :stuck_out_tongue:

I want to know what would happen if a cell vented in a light, would it provide fire protection or be extra dangerous?

I personally keep my most used 5 lights with batteries, then again i only have a few more batteries then that.

possibly this could happen >

I remember reading about that, the theory at the time was unbalanced multi cells or something.

Get a shed.
I keep dozens of yet to be recycled laptop cells in a metal toolbox in the shed.
It smells sweet ! Something has leaked.
Even one of those big BBQ boxes would do.

But good cells are always in torches, with a few charged ready to swap and go, on my desk.