Peugeot Citreon announces their 2009 Peugeot Citreon H2Origin Delivery Wagon:

Newslink (http://www.totallymotor.co.uk/news/manufacturer/peugeot/fuel-cell-research-results-revealed-by-peugeot-$1219840.htm)

This is the second article I've read that uses "range extender" as the means of describing a serial hybrid - I think it conveys the concept well.