From reading the posts this seems to be the same issue as the Toyota Yaris - the 12v battery must be used to start the power train, but the designers assumed it'll be used often (read very often, like an Uber car) that they can fit a tiny 50Ah battery in it.
If the 12v battery is dead you're not going to go anywhere at all. Period.
it's a design fault in my opinion.
I don't hear the problem mentioned so much for Hondas .. is it because there are less of them around than Toyotas? I read in the Toyota forum you need to drive 7k+ miles for the car to be suitable. If you use it as a city car (which they're marketed for ironically) then you'll get this battery issue.