Here is the thing. A very small leak over a long period of time the smelly stuff in the propane goes away and you still have propane in the camper and it may be at an explosive level. Several years ago here where we live a family got exploded inside their camper when the wife went to light
the cook stove. There was no propane smell present. They lived but were burnt really bad.
If your battery was dead B 4 you went to charge it, the detector would not have been working and once the voltage was raised it started working and it went off.
This is a very bad situation. You need to have it resolved before you do any camping. NEVER turn on any electrical
device or cause any static electricity or have any flamible object inside the camper u till you resolve the issue.