This was our wheelchair!
What was really odd is that it was NOT on charge.
We had merely arrived at our cabin, folded it up, placed it in the corner of the cabin and less than 10 minutes later there was smoke coming out of the battery. It has 2 batteries, only one of the them was connected to the wheelchair power but BOTH went at roughly the same time. First smoke poured out, then, in one of them, I could see through a hole on the side and it was glowing! So I took it out of the wheelchair and wanted to get it outside but we'd only been onboard for 10 minutes and so I didn't know where to go. I dropped it there because it went "crack" while I was carrying it. Then I had to run back to the other battery in case my wife was in danger of the other one catching fire, but members of the crew were already there and had seen to it.