General Motors introduced a
mild hybridMild hybrids are essentially conventional fossil-fuel vehicles with oversized starter motors, allowing the engine to be turned off whenever the car is coasting, braking, or stopped, yet restart quickly. It includes regenerative brake and electric support drive, but mild hybrids do not have an...
system called
belt alternator starter (or
BAS) in the 2007
Saturn Vue Green LineThe Saturn Vue is a compact crossover SUV from General Motors' Saturn marque, and is Saturn's best-selling model. It was the first vehicle to use the GM Theta platform. The Vue is the oldest model in the Saturn lineup since the demise of the L-Series in 2005. A second generation Vue was launched in...
and
Saturn Aura Green LineThe Saturn Aura is a mid-size car produced under the Saturn brand of American automaker General Motors. It debuted as a concept car at the North American International Auto Show in January 2005. The production model of the Aura was shown at the 2006 New York Auto Show in April, with production...
. It operates similarly to the "start-stop" system used in the Chevrolet Silverado Hybrid in that it shuts down the engine as the vehicle comes to a stop and instantly restarts it when the brake pedal is released. A
36 volt electrical systemA 42-volt electrical system allows use of more powerful electrically driven accessories in an automobile. Electric motors would be used for power steering or other systems, providing more compact installations and eliminating the weight of drive belts or large wires for high-current wiring...
is used to operate a motor/generator unit that is capable of starting the 2.4L Ecotec engine in less than 500 ms, making the autostart system essentially transparent to the driver.
General Motors introduced a
mild hybridMild hybrids are essentially conventional fossil-fuel vehicles with oversized starter motors, allowing the engine to be turned off whenever the car is coasting, braking, or stopped, yet restart quickly. It includes regenerative brake and electric support drive, but mild hybrids do not have an...
system called
belt alternator starter (or
BAS) in the 2007
Saturn Vue Green LineThe Saturn Vue is a compact crossover SUV from General Motors' Saturn marque, and is Saturn's best-selling model. It was the first vehicle to use the GM Theta platform. The Vue is the oldest model in the Saturn lineup since the demise of the L-Series in 2005. A second generation Vue was launched in...
and
Saturn Aura Green LineThe Saturn Aura is a mid-size car produced under the Saturn brand of American automaker General Motors. It debuted as a concept car at the North American International Auto Show in January 2005. The production model of the Aura was shown at the 2006 New York Auto Show in April, with production...
. It operates similarly to the "start-stop" system used in the Chevrolet Silverado Hybrid in that it shuts down the engine as the vehicle comes to a stop and instantly restarts it when the brake pedal is released. A
36 volt electrical systemA 42-volt electrical system allows use of more powerful electrically driven accessories in an automobile. Electric motors would be used for power steering or other systems, providing more compact installations and eliminating the weight of drive belts or large wires for high-current wiring...
is used to operate a motor/generator unit that is capable of starting the 2.4L Ecotec engine in less than 500 ms, making the autostart system essentially transparent to the driver. The
air conditioningAn air conditioner is a home appliance, system, or mechanism designed to dehumidify and extract heat from an area, or provide heat to an area. The cooling is done using a simple refrigeration cycle...
continues to be operated through a belt-driven pulley, but is disabled in auto-stop mode, providing the "eco" A/C mode is selected.
The BAS system is capable of providing modest power assist during launch and acceleration. Although unable to operate in pure
EVeV may mean:* Electronvolt, a unit of energye. V. may mean:* Eingetragener Verein, a registered club in Germany#eV may mean:* Most Valuable player ShaQEV may mean:* Estonia's official name is Eesti Vabariik...
mode, the BAS system provides about 15-20%
fuel efficiencyFuel efficiency, is a form of thermal efficiency, meaning the efficiency of a process that converts chemical potential energy contained in a carrier fuel into kinetic energy or work. Overall fuel efficiency may vary per device, which in turn may vary per application, and this spectrum of variance...
gain in the city. The system is reasonably simple and inexpensive, making BAS equipped vehicles the least expensive hybrids available.
One major benefit of the BAS technology is that it fits in the same space as a conventional engine. No modifications were required to the Vue's chassis to accommodate the BAS system, with the battery pack housed in the
spare tireA spare tire is an additional tire carried in a motor vehicle as a replacement for one that goes flat, a blowout, or other emergency...
well. This allows the Vue Green Line to be produced on the same assembly line as the normal Vue, producing substantial cost savings and allowing the company to adjust production more easily.
The BAS system uses a conventional 4T45-E
automatic transmissionAn automatic transmission is an automobile gearbox that can change gear ratios automatically as the vehicle moves, freeing the driver from having to shift gears manually...
, although it has been modified to include a more efficient final-drive ratio and includes an electrically-driven pump to provide pressure in auto-stop mode.
This system has already found its way to two other GM models, the 2007
Saturn AuraThe Saturn Aura is a mid-size car produced under the Saturn brand of American automaker General Motors. It debuted as a concept car at the North American International Auto Show in January 2005. The production model of the Aura was shown at the 2006 New York Auto Show in April, with production...
and the 2008
Chevrolet MalibuThe Chevrolet Malibu is a mid-size car produced in the United States by General Motors. It is marketed in the United States, Canada, Mexico, and the Middle East.-First generation 1964–1967 :...
.
In March 2008
General MotorsGeneral Motors Company, often known as simply GM, is a United States based automaker with headquarters in Detroit, Michigan. GM was the world's 18th largest corporate entity and third largest automaker as ranked by 2008 revenues on the Fortune Global 500. Ranked by global unit sales for 2008, it...
announced their intention to produce a more advanced "2nd Generation" BAS hybrid system that includes a Lithium Ion battery and a more powerful and efficient motor generator unit.
CobasysCobasys LLC supplies nickel metal hydride batteries, battery control systems, and packaged solutions for automotive applications, uninterruptable power supplies, telecommunications applications, and distributed power generation...
which supplies the battery had to conduct a recall for leaks in 2008.
Later due to slow sales, GM has relegated the 2010 model year BAS hybrids to "fleet only" status
Other Names
- BSG: Belt-Driven Starter Generator
- BISG or B-ISG: Belt-Driven Integrated Starter Generator or Belt Mounted Integrated Starter Generator
- BSA: Belt-Driven Starter Alternator or Belted Starter Alternator
Vehicles
- 2007-2009 Saturn Aura Green Line
- 2007-2009 Saturn Vue Green Line
- 2008-2010 Chevrolet Malibu Hybrid