RE: LiPo battery low voltage
I have recovered several lipos over the years with success. Did you measure each cells voltage ? Do you have a charger that charges different types of batteries ?
Here is what I did the first time I ran down a lipo. It was several years ago after I put a lipo in my transmitter. I left it on and when I took it out to use it the battery was dead. At the time I only had a cellpro charger and it wouldn't start the charge or even try and restore it. I checked the cell voltage and all were below 2 volts. Everyone told me the lipo was shot and there was nothing you could do about it. I thought about that and decided to try something as I knew the voltage increases when they get warm and decreases when cold. I put the lipo on top of the pavilion roof and left it there all day. At the end of the day the sun heated-up the lipo and raised the cell voltage enough so the cellpro charger would recognize it and restored it . It came back and has been working fine for years but it does not hold a charge as long as it did before the over discharge.
A few other lipos I have brought back by using a multi-charger set to PB (lead acid) mode and connecting directly to the output leads of the lipo with no balance lead connected. I set the charger to the lowest voltage which I think is 3v and 1amp and start to charge it while monitoring it. After a minute or so I take it off and chack the cell voltage . Once it has raised it enough I put it on regular lipo balance charge and finish charging it.
All these packs have come back and gave decent performance however not as good as when they were new.
As long as the pack is not puffed or physically damaged I would say to give it a try.
If you want to dispose of it cut off any connectors you want to save and toss the lipo in a bucket of salt water for a few hours then throw it away.