Loose batteries, fire risk?

An idle but slightly worrying thought just occurred to me.  We have two plastic Tupperware style boxes with batteries in them.  One with good batteries, one with dead ones awaiting a trip to a recycling point.  Mostly loose, a real mix of AA, AAA, D, various sized CRXX type button batteries for various stuff etc.  I try to keep the new ones in their original packaging, but others in the house just rip them open so they all spill out.

Is there a risk of some kind of short generating enough heat to risk a fire?

Is there a risk of some kind of short generating enough heat to risk a fire?

It would be about as likely as a monkey sitting down at a typewriter and producing a meaningful sentence by randomly banging on keys.

Probably not just be careful with PP3 batteries or any others with 2 terminals which are easy to short out.

I normally tape the contacts with electrical tape as these can get hot and might catch fire.

It would be about as likely as a monkey sitting down at a typewriter and producing a meaningful sentence by randomly banging on keys.

How do we know you’re not a monkey?

hurls poo….

Yep, I’ve seen a 9 volt PP3 battery get really hot when accidentally shorted, which is probably what sowed the thought.  I don’t think there are any in there but I’ll check!

At work we just have to tape over the terminals of any battery’s with the terminals on the same face. I.e pp3 9v.

It would be about as likely as a monkey sitting down at a typewriter and producing a meaningful sentence by randomly banging on keys.

Not necessarily, Bruce already noted the PP3 risk, but your CR button cells also have a +/- in very close proximity. We have to tape these at work before they go in the recycling box for the same reason.

What prompted this was that I’ve just changed the battery in a key fob used with a motorcycle tracker. It’s a fat CR button cell and the terminals are extremely close so could be shorted fairly easily.  Only 3 volts so probably not going to get too hot.  I did however find a lone PP3 buried in there! Terminals now taped.  I shall resume typing bollox like a pissed up gibbon until I think of another unlikely scenario to worry about!

CR button cells also have a +/- in very close proximity. We have to tape these at work before they go in the recycling box for the same reason.

That’s a sensible precaution, but it’s still a very unlikely possibility just tossing some loose cells in a Tupperware container. 9V cells with the terminals on the same end are asking for trouble though.

Standard batteries arent going to spontaneously combust, or remote controls everywhere would be causing fires.

Standard batteries arent going to spontaneously combust, or remote controls everywhere would be causing fires.

I know they are not going to do it spontaneously.  lt’s whether terminals being shorted in a big pile of loose batteries could generate heat.  Batteries aren’t shorted out in a remote.

There’s a small but real and foreseeable risk of combustieeeeeeee, eeeeeeee, oo ooooooo eeeeee

lt’s whether terminals being shorted in a big pile of loose batteries could generate heat.

It’ll depend on what’s shorting them and how much energy the batteries have. Eventually something will melt and the circuit will be switched off. That’s how fuses work. It just depends on whether it all gets hot enough to set the box on fire before it melts. Very unlikely with some loose batteries rattling around in a Tuperware container.

Go into any branch of Aldi or your local tip and you’ll find a big plastic pot of batteries for recycling
Keeping new ones wrapped is sensible for various reasons and I suppose it might avoid aa tragedy

What prompted this was that I’ve just changed the battery in a key fob used with a motorcycle tracker. It’s a fat CR button cell and the terminals are extremely close so could be shorted fairly easily. Only 3 volts so probably not going to get too hot. I did however find a lone PP3 buried in there! Terminals now taped. I shall resume typing bollox like a pissed up gibbon until I think of another unlikely scenario to worry about!

It’s not really the voltage, it’s the current capacity (which is miniscule in button cells) and the total charge the battery holds (also miniscule). I suspect you’d struggle to start a fire with an large bag of new ones even if you set out to do so by shorting them all together in a loop.

Just make sure you don’t keep your steel wool in your battery recycling box…

might avoid aa tragedy

Very good

Regular AAs etc, I wouldn’t care unduly. Anything with lithium in I’d treat with a little more care. I’ve seen one go up first-hand and it was… dramatic.

Yeah, I tape button cells and 9V batteries, and they live in a metal biscuit in the garage. I have genuinely wondered about it but also keep forgetting to drop them off at the recycling centre.

Lols at the guide to fuse replacement above… ☝🏼🤣🌋

Just make sure you don’t keep your steel wool in your battery recycling box…

This happened in my bosses van.

Got a lift home, and when he opened the side door to get my tools out I noticed a burning type smell. We searched through the bloody mess in there and found that a large ball of steel wool had been put into the box we kept spare powertool batteries in. The underside that had been in contact to one or more of them was well alight.

Just as well I got a lift back, or it’s likely it would have went up at some point during the night.

It would be about as likely as a monkey sitting down at a typewriter and producing a meaningful sentence by randomly banging on keys.

Place i used to work had two fires in the (very new) battery recycling boxes within a week.
So they put a plate/guard over the tops of the bins to stop people putting large, high discharge batteries in them.

The battery recycling bins at the supermarket here have signs about making sure the batteries are flat, and at the tip they get a bit lairy about putting high capacity/power batteries in the bins, so they make you tape the terminals and stack them seperately (car or motorbike batteries, powertool batteries, RC car stuff etc).

So they put a plate/guard over the tops of the bins to stop people putting large, high discharge batteries in them.

The OPs batteries are 1.5V AAA to D cells, plus button cells. Different kettle of fish.

It’s a good thing that there aren’t many type writers left or more monkeys.

The world is getting safer.

We have to tape these at work before they go in the recycling box for the same reason.

do you recycle a lot of batteries that still have significant charge?  I’m not sure I understand how a typical dead battery is going to cause a fire even if you short the terminals in the perfect way?

You wouldn’t normally throw away batteries with charge left, but sometimes charged batteries get mixed up with the dead batteries, you don’t know how much charge is left in the battery when it won’t work in the appliance and sometimes you want the appliance to work as long as possible and change part used batteries.

The risks are quite low and it may never happpen but an inch of tape reduces the risk.

I’ve chucked a couple of batteries in my pocket before, forgetting there were also keys in there.

Wondered why my leg was getting very hot until I realised

There was a laptop fire (Li ion battery) at a university in Vienna that destroyed a lab – no physical casualties. Written up recently in a journal to publicise the disaster.

Laptop hadn’t been used or charged in 2+ years, and was just sitting in a cupboard. Even for a freak accident, I didn’t realise this was possible tbh.

https://chemie.univie.ac.at/wissensaustausch/news/detail/news/laboratory-fire-2021-nature-chemistry-tells-our-story/

Wondered why my leg was getting very hot until I realised

Done that…

I’m not sure I understand how a typical dead battery is going to cause a fire even if you short the terminals in the perfect way?

An “empty” LiPo battery, i.e. one that won’t run a device any more, probably has more energy left in it than you’ve actually used from full to “empty”.

Li-po’s can go up if damaged/shorted or, indeed expanded – some Sony PSP and phone batteries were known to ‘expand’.

We’ve had a blanket ban on staff charging e-bike batteries in the office at work, until they can put in a fire safe recharging facility.  The guy with a very dodgy looking ‘easy rider’ chopper type ‘electric bike has been reported – work’s banned illegal scooters too, and this home brew ‘electric motorbike’ looks a hazard in waiting – I’d be mightily hissed off if my bike went up !

There was a laptop fire (Li ion battery) at a university in Vienna that destroyed a lab

The OP is talking about a box with some AAA, AA, and D cells, plus some button batteries. Yes, other types of batteries are much more dangerous, but the ones the OP has aren’t those.

The OP is talking about a box with some AAA, AA, and D cells, plus some button batteries.

And unbeknown to me a loose PP3 – terminals now covered.  So if nothing else it prompted me to check for that.  I have seen how hot PP3s can get if the terminals are shorted, hot enough to cause a fire in the right circumstances I reckon. As regards all the others?  Yes I know the risk is incredibly low, but probably not zero.

I come from a background where ALARP is a big thing and I am also aware of bizarre accidents from seemingly innocuous causes.  House and car fires caused by mirrors and eye glasses, oily rags spontaneously combusting etc.

I just wanted to give some thought to it.  Having done so, I probably wont change much except be on the guard for 9 volters!  I reckon that is ALARP compliant in my situation.

We’ve had a blanket ban on staff charging e-bike batteries in the office at work, until they can put in a fire safe recharging facility.

Probably time for this again.

Do you think that press would squash this laptop battery back into shape? It’s swollen up and won’t fit back inside the case.

The risks are quite low and it may never happen but an inch of tape reduces the risk.

My question though, is, was it ever a realistic risk in the first place or has someone conjured up an theoretical possibility with no substance behind it which now means that some people will not bother with the hassle of finding tape and recycling and just dump in a drawer (where they may still present the same risk) or quietly in the ordinary bin (where they will have similar risk and an environmental issue?

I have in my head (but not sure where from) that a PP9 square battery (which on the face of it are the biggest risk of the normal disposable batteries) can only actually put out 0.7A.  Is that right?  So 0.7A at 9V = 6.3W.  Obviously if that is through a thin enough wire you can still get it red hot, and if its in contact with something flammable that could make fire (just a thought – but is “tape” more flammable that the the rest of the battery bin!).

A typical hearing aid or calculator battery (button cell) will be even less.

If 95% of the batteries are “dead” then you are left with 5% of a very small risk.

If it IS a real risk, not something made up by someone with no real basis, then is expecting the user to apply tape really the best way to mitigate it?  Would it be better to put the batteries in trays which nearly packed them by size (which would massively reduce the risk of random rogue batteries which are potentially higher risk).

We’ve had a blanket ban on staff charging e-bike batteries in the office at work, until they can put in a fire safe recharging facility.  The guy with a very dodgy looking ‘easy rider’ chopper type ‘electric bike has been reported – work’s banned illegal scooters too, and this home brew ‘electric motorbike’ looks a hazard in waiting – I’d be mightily hissed off if my bike went up !

I’m going to guess that the H&S manager / office manager type who instigated this rule thinks they are a menace on the roads rather than a real safety risk?  He’s certainly not worried about staff dying as I think thats much more likely if you go home and charge it whilst asleep (something he is indirectly encouraging) than if its done sensibly in a workplace where presumably there is good fire detection equipment and you are awake!

They are a real risk. Years ago teachers of the deaf used to carry spare PP3s for the kids radio hearing aids in pockets. There were occasional melted pockets.

Risk for a used flat battery is low. Ideally you would clip the plastic cover back on the terminals but failing that use tape.