[koolba]

That sounds like a good choice for a hybrid that uses the rotary ICE to periodically charge the battery.

[lttlrck]

Or a range extender generator like in the BMW i3

[phineastcat]

Mazda actually had a Mazda2 EV prototype with a rotary range extender that they unveiled in 2013. Not sure what ever happened with it, though.

[thephilsproject]

I first saw this on the Audi A1 e-tron concept; it was a 250cc wankel for the range extender. I thought that was the future when I saw it, and here I am now with a Vauxhall Ampera (Chevy Volt)!