battery extremly hot after accidentally making mod too tight

[Coastal Cowboy]

Assume that the battery is bad and toss it.

There's no reason to use a battery than can be replaced for less than $15 shipped when its condition is uncertain. It's going to be a risk on the charger, and it's going to be a risk in your device.

 

[Coastal Cowboy]

Like someone already mentioned, dump the Efests

There's nothing inherently wrong with Efest batteries. They are not top of the line, but they are reliable. I have two Efest IMR 18350's that have performed and behaved well in the months that I've used them. No battery is going to take abuse and not show some effects from it. Some batteries handle the stress more gracefully. Others, not so much.

 

[BigBen2k]

If the cell is swollen, or deformed in any way, it's a tosser.

If it isn't, let it cool overnight, then use a meter to check its output voltage. If it's ok, try a small load on it (like a lightbulb) and see how it reacts. If there are any fluctuations in the light, toss the cell.

Never exceed the C rating of the cell; this one's not likely rated for your usage.