Wow! So you lost the entire bottom portion!
It shouldn’t make connection (turn on) at all (under ideal conditions). Obviously there’s enough travel in the spring loaded connectors inside the top portion of the body to force a connection against the external chassis (that’s exposed now in the bottom door) to complete the circuit.
However, using it in this condition is pretty dangerous IMO. As a bad wrap around the positive post of a battery being exposed would be a DEAD SHORT situation which would lead to venting (since the only thing keeping it from touching the bottom door is the wrap)
I would retire it until you can either find the complete bottom assembly (that fell out), or find a replacement bottom door.
You were correct in that you need the exact same model unit to get parts from though.
I’ll keep you posted if I come across a parts unit. But I would also suggest dropping a line to Smoant, and seeing if they can offer a solution (be it complete replacement, or a battery door, or whatever…)
Sorry folks! It would seem a pm bled over into public by accident! Lol