Thanks MrSnuggles. For the most part, laptop batteries are specified and regulated. Of course, people will buy cheap rip-offs and they put everyone at risk. But, as i see it, ALL vaping batteries are unregulated.
Ultimately, every passenger has signed a contract to obey the instructions of the airline, via the flight and cabin crew. Some of the rules are antiquated and some may seem overly cautious to many (including myself, on occasions) but that is the contract of carriage.