Chinese powerbanks are so fucking dangerous. Cheap price = cheap quality. Alright, I get it, but that's not my point.
Today my dad gave me his powerbank and wanted me to upgrade it.
A 50k mAh powerbank, but it is far away from 50k mAh. He bought 12 6000mAh rechargeable batteries.
Before I started replacing it and resoldering the powerbank, I decided to open up the Chinese 50k mAh battery. A lot of aluminum foils covering the batteries. That's not great. A very high chance for a short circuit to happen.
Anyways, I carefully took the aluminum cover halfway out.
I took a (plier?) with plastic handles and grabbed the pack of batteries with it to not put myself into danger.
And BOOM! A short circuit.

Btw. It smelled very weird when I took the aluminum cover off of the pack.

Were the tabs covered with kapton tape? If not, that's indeed a severe hazard. You'd assume that they have a little bit of safety regulation going on...

The weird candy-like smell is normal btw when they're concealed like this. The cells always outgas a little bit. When pierced, the smell is a very strong and unpleasant one.

@Condor from the first look I was sure this was your rant 😁

@netikras i too thought it was @Condor

@netikras @gitlog most of my powerbanks have already been reduced to single cells 😜 I'm planning to build my own in the future though. But in order to be able to use 18650 cells, I'd first have to figure out how to tab weld nickel plates on them. So far I haven't been able to do this without spending half a kidney 😅

@Condor dunno how about @gitlog but it wasnt the powerbank topic that was similar to your ranting. It's bashing on lo-quality electronics in general :) it's just smth you do 😁

Kapton is known to be the cause for several crahed airplanes. The Kapton insulation of their wiring looms absorbed moisture and began to crack. Kapton is very nice, but not too great as a permanent and only insulator.

I'd recommend to buy one of these “empty” powerbanks you can fill with your own 18650 cells if you want one with very high capacity. No need for delicate pouchbag cells and no need for spot welding either. And you can reuse old laptop battery cells or buy knowm, good quality ones.

@Condor: I've seen people building dual-pulse spot welders from these “car HiFi” electrolytic caps with “1 F”. I've tried to reproduce this but my capacitor's ESR is far too high, and I have no idea how to find a good quality one since they all look basically the same (“ULTRA energy+ 30000 mEgA” or whatever).

Seems like the battery pack was an illusion. It was a big ass battery cell.

Why would you buy a power bank from an untrusted source? 🤔

@620hun it was my dad. Not me.

@-ANGRY-CLIENT- you, as in anyone

@620hun oh haha. That is a good question. Maybe it is due to the lack of knowledge.

@Condor yes they had kapton tape on them

@Condor it was not candy-like. It is hard to describe. It was more like very strong ammonia when I started taking the aluminum cover off.

@-ANGRY-CLIENT- hmm, interesting.. might've been the lithium cells' outgassing, maybe the tape that was used.. most likely is the lithium cells though. They tend to have a weaker smell of their components when it's disassembled after months or even years since confinement into their enclosure after manufacturing though. I'd bet that it was that kind of smell. In that case it shouldn't be much of an issue. If you suspect that it's been pierced or even had risk of internal shorting, always put it in an explosion-ready metal dish and keep flammable substances out of the vicinity of the lithium cell though (and keep such a dish nearby during any disassembly of those). They're quite nasty when they short. I've had one that I'd cut right through with snips in an act of anger and sheer stupidity.. it wasn't fun. I effectively treated it as a bomb and left it to dump all its energy into heat and to cool down in a metal dish placed outside for several hours. It was a harsh lesson for me...

@7400 oh yeah, those are supercapacitors iirc. I've seen some people use them in a bank to increase the voltage while decreasing the capacitance.. but not entirely sure if those could weld. Their ESR shouldn't be as much of an issue as their rated voltage is though.. but I don't have any of those supercaps to experiment with unfortunately 😔

No need for plastic handles. The voltage won't hurt you unless you stick your tongue to it. Also, only teardown empty batteries and keep your explosion containment pie dish ready.

@Condor definitely could. See Afrotechmods about playing with ultracaps. Those things are evil.

@Condor: The supercapacitors definitely can weld, but I'm talking about normal electrolytics. The problem is that most of them aren't anywhere near the specs since the typical customers have no way of checking.

Thanks for reminding me, that I should go ahead and recycle my punctured batteries and not sotre them in a carboard box!

@JFK422 you're welcome! :)

Isn't it easier to just buy a bunch of 18650 cells from a known brand (Samsung, LG, Panasonic, etc), if you really want to go the custom route?

More expensive than "powerbank from random deal site", less expensive than rebuilding your house after a fire.

@bittersweet the thing is that I was not the one buying it.

@-ANGRY-CLIENT- But you can be the one slapping the buyer with a newspaper. Fulfill your destiny!

@bittersweet not if the buyer was and is my father.

@-ANGRY-CLIENT- Depends how fast you can run...

@bittersweet lmao nah would never do that, even if I was the movie character flash himself