A fuel cell power system, comprising a fuel cell which generates D.C. voltage while operating; an ultracapacitor which, in operation, is electrically coupled with a load and has a voltage condition; and a circuit which, in operation, electrically couples and decouples the fuel cell to the ultracapacitor...http://www.google.co.uk/patents/US6497974?utm_source=gb-gplus-sharePatent US6497974 - Fuel cell power system, method of distributing power, and method of operating a fuel cell power system
