Conventional vehicles that switch off when they stop, however briefly, are called stop-start or, misleadingly, micro hybrid (because they do not usually provide electric traction and they are not therefore a form of electric vehicle). The fuel saving, or increase in range, is 5-8% and the response in the marketplace is dramatic because this is both an easy way of meeting ever tougher pollution regulations and providing a valued sales proposition.
Even manufacturers of mining, material handling, agricultural and earth moving vehicles are now incorporating the technology which is mainly based on advanced lead-acid batteries, increasingly with a supercapacitor added so they do not fail to work in cold weather or when many stops occur.
Maxwell Technologies has sold over 600,000 supercapacitors for this use, mainly in cars, and followed on with a complete conventional vehicle battery replacement consisting of supercapacitors across a smaller lead acid battery with both a cost and a performance advantage claimed. Use of a lithium-ion battery is another option for stop-start but that has cost issues.
Increasing range by battery deep discharge