Then you should get new solder and new flux. The stuff you can get today is not corossive.
I don’t see how corrosion gets a cell to flame but the picture is really weak. Also these packs do usually get spotwelded and I thought you wouldn’t need solder of flux for that…
I am really confident that the charging was the problem
That’s why I would be interested in the used circuits, charger and batteries. I guess we would find the problem quickly.
My rule of thumb for battery packs with 18650 is 5$ per cell, if it’s below That price you need to be suspicious.
So such a bike pack must at least cost 20$, if it’s below you can be sure it’s garbage.
I am not the Chinese manufacturer using the problem materials.
It looks like they used ordinary steel, not stainless, to make the connectors in the battery pack, doesn’t it?
Yeah, it is a simple pack that will end up with unbalanced cells, so for sure the charging process seems likely to have caused the cells to vent.
Then something ignited somehow.
Click the picture showing the corroded connectors for the reviewer’s description:
It could be a balancing problem between the cells, but the cells in my bike light battery pack have a protection on each cell.
The balance in that battery pack is not very good, but if 4 of the 8 cells (4p/2s) are too low the battery pack cuts out.
That is why i made extra connections to charge the battery pack with the hobbycharger to get all the cells to the same voltage.
And when i was soldering the extra wires i noticed that the pack was not waterproof, the rubber sleeve is just wrapperd around the cells, with a piece of black plastic at the bottom (nu glue or other sealant).
I have not seen any corrosion on my bike light battery like in the photo above…
The connections in that pack are not soldered, you can see the spotwelds.
So i don’t think flux caused the problem, for what i can see it was moisture that caused the corrosion.
Throwing water on a charger plugged into the wall was the second dumb thing he did.
Those powder fire extinguishers are the ones most people have, me included. I hear they can corrode TV electronics years after the powder was released indoors. I’m considering getting a ‘Clean Agent’ one. They are the ultimate I hear. It beats a corrosive cloud in your home.
I’ve ordered a bunch of cells from FastTech and never had an issue. All of the physical qualities are correct and they test as they should. I would say they are just as reliable as any of the US vendors - the only unknown is who their suppliers are (and the suppliers beyond them) and that’s true even of our preferred US sellers. I’m sure there are other chinese vendors who may not be as legitimate though.
Buying cells form chinese vendors is a necessary evil, no one wants to have a cell blow up, but we have limited options.
I wish we could guarantee no cell is ever counterfeit, but we just can’t, manufacturers don’t sell cells directly to the public so we are stuck with the current options and can only make the best of it that we can.
I have a fluke meter that is left over from my auto technician days. I may check my cells. I am not used to this as all my rechargeable stuff (laptop, phone, cordless power tools ) pretty much takes care of themselves. They go dead you charge. If you leave them plugged in past full charge the limiter kicks in. It sucks that you should have to babysit these things like a car battery but if that’s the way it is I guess “It is what it is” as my dad puts it.
Glad to hear this guy and family are ok. In this case most likely a bad charging circuit and/or crap cells...and lucky for us we have some here that graciously gives us his time to test and inform us of chargers and batteries :)
This could have happened anywhere and with many more things than a bike light. One example is your car. Not going to get into it but just Google "car fire"...and 9/10 times it is caused by a shorted battery while just parked in the garage.
I would rather believe that the guy who took the pack apart had his finger shoved up his … aboral pore … and got … fecal matter … on the pack, than to think someone somewhere got paid for doing that. And then I notice the fact that the welds (in what looks like a scrap of shiny metal s/he found on the floor) aren’t even made properly.
This!
I think it needs to be said even more bluntly.
LISTEN PEOPLE! If you see corrosion or (even worse) RUST on your battery packs, Do Not Charge them, Do Not Insert them in any device, and do not leave them in your home or place of business another moment! Recycle them and move on to your next set!
I’m really disappointed that this needed to be said the first time, but perhaps it really does need repeating: You have to Look. You have to Pay Attention to what’s happening around you. You have to Think Clearly and make good choices about how you’ll interact with your environment. Or you can expect a violent, painful death. And destruction. This guy was lucky, that’s all. Darwin missed the mark, that day.
It’s hard to witness all the blame-throwing at “cheap Chinese cells” and even laptop pulls (???), for an incompetent pack maker or an even less competent owner, but I see the magpies are quick to squawk…
At least the guy this happened to confessed his sins. I was disappointed that he didn’t seem to “get it”, and that he “saw” the review article but didn’t seem to have read that article; but he stated that he had left the charger sitting on a stool next to a stuffed chair, then went for an extended bike ride.
Little wonder the rest of the story would play out in its usual manner…
EDIT: And to his credit, he never said “dude” a single time!
As BLFers we know a great deal about batteries, lights and electronics, most people know charge, operate, recharge. They have no interest in the nuances of why things work, they just know how to operate them. A red flag to you is a curiosity to someone else. They assume products are as safe as other products, that the government they hate for protecting them is protecting them.
Stories like this are why I don’t leave my laptop plugged in charging unless I am in the house. I also charge my stuff on the kitchen counter, not on my couch. And I have a large a$$ fire extinguisher. No guarantees, but less risk.
I bet dryer fires are much more common than battery fires. Do you take precautions to minimize the chance of dryer fire in your home?
We bought one of the first “Shark” vacuums (like, v0.something, not even v1), installed the cheesy flex-hose that came with it, and leave it ready-to-go by the dryer. It replaced an ancient Hoover portable that was made for a beater-bar head & therefore the hose was worthless.
“Vacuum off the lint filter” has always been a part of “Load the dryer”. I guess that’s why our lint duct, 20yrs old, installed new by us, is still clear and clean…
Dryer fire? Not in my house.
But you’re right. In the grand scheme of things, exploding batteries are pretty low on the threat scale. A few simple facts to understand, a normal sense of environmental awareness, and you’ll only get to read about them.
And BTW, your laptop has vastly more engineering in its charging circuit than our toys ever will. That’s why recycling laptop packs is such an excellent source of dependable, top-quality batteries (admittedly with a bit of work to acquire). I have an ancient Dell on the bar which stays plugged in 24*7 except when I’m walking around with it. It’s on its 3rd battery pack now and it is in excellent shape. SWMBO doesn’t even walk around much with her Latitude, so it stays on the wall wart more, & likewise is doing just fine. It would never even occur to me to try that with a “regular” battery charger!