In reply to 2M0NCM:
I’d consider it gubbed Neil. Dispose of it and buy some new ones. Luckily they are not terribly expensive to replace.
In reply to G3CWI:
The info in the link you give is widespread across the net Richard. As you point out whether it is sensible advice or not is unknown.
The actual link you give misses out an important step which makes the immersion in salt water a waste of time. Lithium cell chemistry is designed to stop any metallic Lithium existing in the cell. Still Lithium is one of the most reactive elements you can find and I’d be wary of getting the contents of a pack anywhere near water.
The other important point is assuming you do this and end up with an inert cell pack, what do you do with the contaminated water? Pour it down the drain and pollute somewhere else?
No, the sensible thing would be to discharge each cell in the pack slowly (use the charge/balance connector) and then take it to your council recycling centre. They normally have a place for batteries and many have a special area for Lithium cells often marked for Laptop batteries.
That disposes of the faulty cell, the next stop on this journey is why did it fail? Is the charger now faulty? Was the cell physically damaged at some point? I’m not sure which charger you use, some are fast chargers that charge all cells types and tell you all sorts of impressive numbers such as the weight of electrons added to the cell etc.! I’ve got a really dumb slow charger. It only charges 2S or 3S packs and only at 200mA. It means that it takes a long time to charge the cells up. It also seems to stop short of fully charging the cells at 12.4V for a 3S1P pack. I don’t know if this is good or not but applying a smaller current will stress everything less.
I’ve been using my LiPo packs for about 2 years or so now and I’m quite convinced they don’t have the capacity they used to have. Even so I’m hoping I can squeeze another year out of them.