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Electric Vehicles Research
Posted on February 25, 2011 by  & 

Microhybrids sweep the board

Faced with increasingly onerous pollution legislation, manufacturers of on-road vehicles are finding that making their vehicles switch off if stationary for more than a few seconds is something of a quick win.
Such vehicles are whimsically called microhybrids despite usually not being electric vehicles at all because they do not use electric motors for traction. Most recharge the enlarged starter battery by regenerative braking. A few have a small electric motor assisting initial acceleration making them EVs.
Issues remain however, such as whether even the best lead acid batteries are up to the task in all the temperatures and duty cycles encountered. Supercapacitors are sometimes added and lithium-ion batteries are sometimes employed. Time will tell who is right.
Certainly microhybrids are far less expensive than full-fledged electric cars. Microhybrids are already on the road in Europe and Asia, including tens of thousands in India.
Many countries have raised their mileage standards. A microhybrid system can improve gasoline mileage by 6 percent to 10% (more for the less efficient US cars) and the qualification cycle is quicker than the qualification and testing cycle for batteries for a full-fledged hybrid or regular car.
One analyst believes that, by 2015, 32% percent of the batteries sold to hybrids will be made for microhybrids. However, when IDTechEx uses the term Hybrid, we refer only to genuine electric vehicles i.e. with electric traction at least some of the time.
Meanwhile, the latest to add this stop start capability are General Motors where its 2012 Buick LaCrosse will have "eAssist" technology. Microhybrids contain a small electric motor and a fairly small lithium-ion battery pack to help a car to go from zero to cruising speed. The batteries then get recharged through braking.The additional motor and batteries increase mileage by 25%, according to GM.
The LaCrosse, coming out this fall, will get 26 miles per gallon in the city and 37 miles per gallon on the highway. In addition, GM has a Buick Regal coming out with a microhybrid unit at around the same time.
In addition to the many microhybrids already rolling out in Europe, this year we learn that the new Peugeot 308 features the next generation Stop Start "e-HDi" micro-hybrid technology. e-HDi is based on the combination of a 1.6 liter HDi Euro 5 diesel engine and a reversible alternator. Relying on an alternator control system (Volt Control) to recover energy during deceleration and a hybrid battery to store and deliver additional energy on startup (e-booster), the HDi unit allows:
  • a 15% reduction in fuel consumption in urban traffic;
  • a 5 g/km reduction in CO2 emissions for approved cycle fuel consumption;
  • 40% faster restarting (400 ms) than with an enhanced starter stop & start;
  • activation of engine cut-out from 20 km/h with a manual gearbox (8 km/h for the electronically controlled gearbox);
  • increased driveability of the Stop & Start system (silent operation, no vibrations).
The second-generation reversible alternator has a power of 2.2 kW and allows up to 600,000 restarts. The Stop & Start function can be driver deactivated.
Continental AG is supplying Maxwell Technologies ultracapacitor-based booster systems to PSA Peugeot Citroën for the second-generation e-HDi systems.
CO2 emissions now start from 98 g/km. The new 308 will receive its world premiere at the 2011 Geneva Motor Show and will go on sale from April 2011 in Europe. It is the second Peugeot model after the 508 to offer the system.
which has now been renamed from Future of Electric Vehicles to reflect its unique covering of the whole subject.
The giant automotive companies with electric vehilce interests take a global view. For example, GM has its Adam Opel and other subsidiaries across the world and Tata of India has Tata Motors Europe and other subsidaairies across the world promoting its electric vehicles. Now smaller automotive companies such as Tara International, Tesla Motors, Peraves, Bluebird Automotive, eCRP and Alke' are also expanding globally with electric vehicles. A similar thing is happening with aerospace companies involved in electric aircraft such as EADS and boat companies, even small ones such as Kopf Solarschiff.

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Posted on: February 25, 2011

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