I dont trust cheap chinese items.
I always prefer going with genuine devices.
I was thinking to buy that 18650 power bank box… but now… obviously not
I know you swear you put the cell in the right way, but to me it looks like you put that one cell in backwards and the positive and negative of the cell shorted out on the spring. I can’t explain the picture of the negative end of the cell. Can you take a picture of the positive end of the cell?
This was not a product I thought was bad, since I new original Xiaomi 10400 PB cost $16 with batteries, I was sure $6 was not a really cheap deal for a empty box, since 4 x brand name batteries cost from $2 - $6 buying on sale, or in packages of 50 from Alibaba.
The rest of the stuff I have talked about, was stuff I ordered before joining this forum, and before I was enlightening 
About the battery the wrong way, you did see my picture?
As you clearly can see, it was inserted the right way. If you look at the pictures here… you can see there is no damage to the positive side, and that the negative side, was the side where I put the battery.
So you are saying that I lie? Or just want my money back or something? In this case, I will not ask for any refund or something. I have another order for 7 more on it’s way from Gearbest.com, so I will see if I try to use them or not. I have to say that I opened a second PB, inserted the same types of batteries (not the bad one) and it’s totally fine. Works 100%. So most likely there was something wrong with this one PB, or the battery, but since the battery still has 4.2V on it, and seems like it works (has not tried it in anything) there has to be the PB? Or?
It looks like a production fault with the battery voltage shorted. No protection in the power bank will help with that, except if they had put a fuse in the wire.
I doubt that it caught fire, it was probably just the wires getting red hot.
If the only damage is that spiral, you might have put the battery in the wrong way.
I will suggest you do a few tests on the battery before using it again:
If you have a analyzing charger, give it a spin.
See how much voltage it drops when laying fully charged for 24 hours.
+1
Here is some pictures of both sides, maybe the “crack” at the side on the top had something to do with it? Of course, that could have happened when I trow it in the ground to getting the battery out…
[quote=myhken]
That sounds like the correct explanation.
You are the real expert here, when you see the pictures here… and the rest I have posted. Do it seems like I put the battery in the wrong way?
My Multimeter says the battery has 4.2V still, but why risk it. I just trow it away. I have plenty others.
But really, you can see the melted plastic on the negative side on the battery, and that the positive side is perfectly fine. If I had put it in the wrong way, how could I get melted plastic on the back of the battery (then facing the positive side on the PB) when my pictures clearly shows that there is no damage at all on the positive side of the PB, just on the negative side, there the negative side of the battery was.
[quote=HKJ]
Thank you, if it was to me you wrote it.
Put it outside the house in a metal container (or in a bucket of water) and recycle it properly.
Yes, and one of the outer turns of the spring got a connection through the crack in the isolation on the battery.
Of course, having it in my fireplace is just to keep my house safe. I also have a box of batteries to I have got (like Ultrafire and the 5000mAh blue battery from Gearbest.com) that I’m going to take to the recycle center next week.
But why is the melted plastic on the negative side of the battery? Do you see any damage to the positive side of the power bank?
And you can see the melted plastic on the negative side of the battery, and there is not any thing on the positive side of the battery?
Still, you think I put it in the wrong way? How did the melted plastic and burn marks come on the negative side of the battery then?
+2.
You buy cheap crap hoping for a good outcome, then seem shocked when it is indeed a crap product. Now you are playing with ‘fire’. What amazes me almost more is the support you are getting for this repeated behavior. You’ve been warned off numerous times.
Come on, a 4-battery power bank for $6? You can barely get a decent single for that. You already knew that and did it anyway.
Remember something it has been on it’s way before I joined this forum. And how can you call this crap, when the price seems right for this product?
http://www.gearbest.com/chargers/pp_186601.html (it’s $6/pcs for an empty shell)
And I did use a Sanyo UR18650ZY battery, that is not a crap or cheap brand. So how could I see this come?
I have used this forum and other now to get better information about products, stores and sellers, and have ordered lots of quality stuff after I joined here.
But the power bank was ordered from Gearbest.com, and I have no information about they selling crap. Before I got the blue 5000 mAh batteries (of course, I knew they was not 5000) and now the power bank shells. But now I know that I can’t trust Gearbest.com for good quality either, like Ebay, Aliexpress and any other site.
Maybe it is my first explanation then. There is no mystery why the spring got hot, there the wires are close together and will help heat each other.
If you have a ohmmeter check the resistance from + to - in the box, if it shows nearly the same value as shorted probes, then the box is shorted.
If the box wasn’t defective from the get go, I’m thinking it’s still good now. If the box is shorted all of the springs would be damaged. The short had to be the cell.
I would also expect that.
The problem is with the heat damage at the back of the cell and the front do look undamaged.
There is nothing at the back of the cell that can short (Except on a protected battery).
At the front it is possible to short the cell and fairly easy if the wrapper is damaged.
I.e. there are two way you can get the short, either from the centre to the can at the front of the cell or from the centre at the front and all the way around to the back of the cell.
Was that battery in in your BT-3100 when it heated up and stopped working?
wow… that’s insane… I’m glad it didn’t explode!
Although this doesn’t take 18650s, I wonder if the Fujitsu FSC341FX works better (if you can find it, that is)…
This is why I originally thought that there already was another cell inserted adjacent and was popped up so that the cell case was shorting the + and - connectors of the box. Then as the cell in question was inserted it shorted out through the case of the improperly inserted cell adjacent to it. That is the only scenario I can think of that explains the spring, the negative end of the cell etc.