You don’t need a university course to remove tape and desolder or pry connections. How ridiculous.
You’re making light of a serious situation — yeah yeah it can all work out — but there’s many instances where it works out really bad — If you’ve ever been around a venting Li-ion cell, then you’d understand
Good luck with your pack — using one oddball cell can be disastrous also
httphttps://www.youtube.com/watch?v=1qOM5ih0IHg://youtube.com/watch?v=
Your method of ripping off the welds might have introduced weak spots in the battery.
You cannot replace one battery with another one because all are in series. One might discharge earlier or later. Replace all seven batteries with new ones and use the old ones for safe applications if you like.
Soldering to Li-ion batteries is usually a bad idea. The heat will cause damages that you can’t directly see. There are people who do it successfully (not more than 2 seconds per cell, cool down immediately), but nobody knows the state of the batteries. One out of 100 might have gone bad and cause an explosion weeks later.
If you’re going to “experiment” with batteries be sure to take precautions; especially with lithium. (bucket of water nearby)?!
!
Pic shows what happened when I was experimenting with nimh and a camping shower; I still don’t know how it happened.
My guess is that the “the spirit of dum ass come on me.”
P,S, Big difference between venting and exploding. (face shield)? 
Even a button cell can go boom for no reason.
Anyone can throw together a bunch of 18650s into a battery pack.
You’ve gotta ask yourself one question: “Do I feel lucky?’ Well, do ya, punk?” :laughing:
Never Throw Venting Li-ion Cell in a bucket of water — It’s been proven that it accelerates the chemical reaction
I’ve mentioned this before — I fool with a lot of batteries — I have taken apart 1000s of 18650 cells with no problem — One afternoon sitting at my desk in the AC, I was taking apart a 60v pack of VTC6 cells — all of a sudden a cell started venting — Like a lit Roman Candles in the house — I was very lucky it was only one cell and I was able to grab the pack to get it outside — No burns to me or the house — Sooted up my desk and office some — I learned my lesson that day and I consider myself lucky—- I take them apart, build outside on the carport where I can throw them in the yard
All these products with Li-ion cells ( especially cheap surplus ) can be very dangerous —- especially when charging — most people don’t realize you shouldn’t charge these when they’re hot
LifePo4 cells are much safer , but have the same issues when charging in extreme heat or cold — But they only smoke , they don’t go BOOM
There was an Old Illustration Joke on the wall of a Tattoo Shop — It was a suicide bomber getting his lesson — The caption said ” I’m only Gonna Show You This Once ”
Seriously?? You are going to just replace one battery, the bad one with a “non-bad” one.
Will the replacement be the exact same battery as the bad one or a random replacement??
……
Good video chops728, thanks.
The pictured XTAR VC8 can test battery capacity, so I can pick one with most similar capacity from my inventory. However I woke up today and decided to keep the cells and sell or give away the fan.
Good to hear. Just wanted to add that measuring the capacity is not enough. You also have to compare the discharge profile and internal resistance.