Originally Posted by
windowontheAside
I think you may run into problems with the battery. You can't check it in, but I'm not sure one that size would be allowed in hand luggage either.
I should have known this was not going to be as simple as I'd like
FWIW, I found this link with a bit more info https://www.britishairways.com/en-gb/information/disability-assistance/assistance-available
Seems up to 300 Wh battery is OK in cabin and I believe I'm looking at 2x 12V 12 Ah batteries, which I make to be 288 Wh (?).