From what I’ve read, Li-ion cells / batteries over time can develop internal threads or filaments (also known as “dendrites” I believe, as with neuro-cells).
Evidently, these microscopic, branch-like structures “grow from the anode toward the cathode during charging, potentially penetrating the separator and causing internal short circuits, fire risks, or premature battery failure.” –Argonne National Library and scads of [other links](lithium-ion batteries develop dendrites when charging)
Me, on the one hand I’m typically all-thumbs upon power cell chemistry, but OTOH don’t want to burn my place down accidentally. At the moment, I’ve taken to removing most of my collection of lithium-ion cells (apart from my cellphone battery), and placing them in lined, steel pans. Also, when I charge my cellphone these days, I put it in a steel pan, like in the OP. Just to be sure, you know?
Now, do I think that the risk of such Li-ion “dendrites” in cells escaping their outer, protective casing is high? Absolutely not, under normal conditions. (altho that also comes down to quality of the battery, which might be quite sketchy, depending) Meanwhile, do I think that such a potential fire might be disastrous? You betch your bippy I do! (just look at poorly-made ebike batteries for some examples)
So I’m thinking that both old Li-ion cells and ones which are frequently recharged (as with cellphone batteries), are at a higher-level of risk, FWIW.
Got an opinion on all this…?
I store sus cells inside a glass jar inside an old metal can with sand in between. Not very convenient for charging though… Some people use no sand but two metal cans, with a stone/piece of brick between their bottoms for some heat insulation. This is easier to pull cells out of (no sand spill if tilted) but their terminals need to be taped over to prevent contact with the sides.
But yes, the last time I had to pierce a cell I did it on an old tray like this (it was too bloated to disassemble the powerbank whose circuitry I wanted to reuse; it’s relatively safe to pierce the outer pouch and not the internal structure (!), obviously then it needs to be disposed of either way − just think how much pressure was needed to bend the milled aluminum like this)
I usually only charge sus cells when I’m in the room but there’s plenty of dirty old heat-resistant containers in the tool shed so I could leave it in one for overnight charging. With enough thickness and surface area, like the tray you showed, it will likely distribute the heat of a single 18650’s thermal runaway without the other side getting hot enough to ignite what’s underneath (I put it on bricks to be safe, and cover it too, the gas pressure inside a cell releases lots of kinetic energy if it bursts). Glass jars aren’t conductive and withstand lots of heat but might break in an explosion, which is why I add another layer; a glass jar on a tray should be enough for charging a single cell, at least that’s what I did last time.
Excellent; thank you for the extensive explanations!
Biggest thing that’ll help is buying high quality batteries and cells. Don’t buy cheap power tool clone batteries, or random cells off amazon.
Anything sketchy i charge outside, and I don’t charge lipos when I’m not home.
I don’t leave batteries charging overnight or when I’m away from Home. Thats about it.
These bags are what many rc hobbists use to store and charge lithium in. There are many different form factors (and price points) to pick from, but they all work to suppress the potential flames and vent off the smoke in a safer way than it just venting in open air.
I have had a battery vent off violently after an rc car I had hit a telephone pole guy wire sideways at 70mph, and it is indeed something you want to contain should it happen indoors.
Best practice is to just be present when charging, and use a bag if you run cheap/old batteries. An old metal toolbox or something would likely work as well, just anything to keep the flames down.
These bags are what many rc hobbists use to store and charge lithium in.
Oh, nice!
When / if I figure out an alternative to Amazon, I’ll be sure to get some of those.Check to see if you have a hobby shop in your area. Most carry these in stock, and it helps support local business rather than Scamazon.
But also be prepared to have your mind blown and maybe pick up a new hobby. 😂
But also be prepared to have your mind blown and maybe pick up a new hobby.
I actually did have some attraction to RC gadgets as a young man, but never quite took the plunge. As an older, disabled bloke who’s mainly housebound, I’ll just have to do it in another life. 🙂
I have a timer on my charging station to disable it at night time.
My previous smartphone which was a pretty cheap brand (work gave a stipend and I got the cheapest one to keep the monthly cost below what they gave. later I got a better one since I had built up some overage). Anyway when it died it was by its battery puffing up and burthing through the phone body. No fire though so thats good. I would assume at this point charging software is optimized so I would think overcharging would be something that just does not happen but maybe I assume to much.
Anyway when it died it was by its battery puffing up and burthing through the phone body.
Scheiße. I recall having one like that some years back, and I panicked and tossed it in our dumpster. Probably could have done better, but I didn’t want to take the chance.
I would assume at this point charging software is optimized so I would think overcharging would be something that just does not happen…
Yes, from what I’ve read, most software is generally very good about not overcharging. However, with counterfeit product, who knows…
I worry about my scooter but I’m hoping if it doesn’t swell it will be ok
Large battery packs (tool batteries and bigger, but some powerbanks too) usually consist of canned batteries (most commonly 18650), which can build up enormous pressure without visible damage, although worse electrical properties like low capacity and sometimes self-discharge can manifest by then.
I mean, one of Louis Rossmann’s previous e-bike batteries combusted spontaneously and violently, and he’s done tons of qualified modifications to the bike so he would have noticed any major irregularities.
Well fuck
I worry about my scooter but I’m hoping if it doesn’t swell it will be ok
Yeah, I was thinking about an e-bike, but if I store it in my complex’ parking garage, there’s probably a decent chance it will get stolen. If I store it in my apt, then it would pretty much be a nuclear disaster if the battery pack went. (lots of wood & ignitables)
