When the battery is full, the genset is shut off completely.
With a multi-gear transmission, a engine while it is accelerating the vehicle is *by definition* almost never at peak efficiency. With proper gearing, it can achieve maximum efficiency on flat ground with no wind. Add an up hill and or a head wind, and the engine is forced off-peak. How much off peak? These are large factors not in the control of the driver.
Electric motors have a very flat efficiency curve that is 2-3X higher than an internal combustion engine. The recent serial hybrid *airplane* claims a 25% improvement in fuel mileage.
World?s First Aircraft With Serial Hybrid Electric Drive - Siemens Global Website
Why are we discussing the merits and challenges of various hybrids on this thread? We already have a thread on parallel hybrids:
http://ecomodder.com/forum/showthrea...ids-15069.html
And we have threads on serial hybrids:
http://ecomodder.com/forum/showthrea...ids-13213.html
http://ecomodder.com/forum/showthrea...ker-14852.html
http://ecomodder.com/forum/showthrea...ike-19843.html