Not sure how accurate the blowout graphic is under the heading of "Aircraft grade magnesium alloy frame" is, but it seems to show just one battery under the platform. The whole design of it appears like a miniaturized version of a Segway.
http://www.ninebot.com/ninebot/ninebot-mini/index.html
The marketing is unintentionally funny. In the next section of that same web page is this gem: "Despite a complete safety guarantee, raising awareness of safe riding is also required – so don’t ride near people or vehicles or on freeways."
That would leave... riding alone on a path that allows Segways...??
