Be afraid. Be very, very afraid. You are playing with fire.
And... enough with the movie sound-bites! But you are dealing with a significant fire risk dealing with abused lithium cells. First, I would not leave the batteries in the coach while trying to revive them. Try all your science projects in a fire-safe location. Second, pay strict attention to the battery temperature. If the batteries have a working BMS (Battery Management System), much of this is handled, but be forewarned the BMS may only be programmed to deal with normal State Of Charge depletion, and won't know what to do beyond that.
It might be time for an expert. One with adequate insurance.