[privatelypublic]

Can't recommend charging cells that have fallen below their official stop voltage- the liability and risk is too high. However, numerous papers have shown that the serious risks happen if they're reverse charged.

I wouldn't use anything but a bench supply stuck outside though.

[joecool1029]

As I said, it's against all recommendations. I've done this a few times over the years though and haven't hit the copper shunting problem described in literature. If they did have that problem my charger would pick up the short and stop charging them.

I did have a failure once and it was on a new molicel. I damaged the outside wrap of a cell while building a pack and it had a short and self-discharged the cell, likely reverse charging it in use. A week or so later the charger rejected it. When I pulled it out it was a fully shorted cell that would accept no charge, but it did not catch fire.