New one on me, got called out yesterday to a holiday park for a gas leak, possibly from two x 2000lts tanks. Customer had been awoken by a "gas" alarm. The place is stinking but definitely not a Propane smell, my gas detector is going mental, the smell was changing from sewage to strong piss to ammonia depending on how close I got to the camper, checked the gas fridge for a refrigerant leak (ammonia) that's ok, cupboard with a Truma water heater has a really strong smell but no obvious cause. When we lifted the seat to get to the Lesiure batteries, F@$k me one battery was red hot and gassing like fook, pulled the fuse and it just kept going, got it out and away from the camper, Site manager has gone to get advice from Google or the Fire brigade, 50mins later Trumpton turn up with not a clue what to do with it apart from telling us it's still 70°c....ended up pulling the cover off a pouring water in untill it stopped venting.
So the morale of the story is maybe the vent pipe that was still coiled up and taped to the side of the battery should have been vented to outside....The gas alarm was actually a CO alarm...I assume the gas that was being detected was Hydrogen so a lucky escape for the owner's.