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Belt Alternator Starter (BAS)
The Belt Alternator Starter or BAS-hybrid vehicle is a new trend in hybrid vehicles. This type of system is often referred to as a mild hybrid. Rather then have an expensive full hybrid system in a vehicle for maximum fuel economy a relatively cheap BAS can be added to a vehicle line to make modest consumption reductions for a much lower price.
A Sophisticated system controls an alternator generator mated to the engine to stop the conventional powerplant in idle or deceleration as well as offer added torque in certain situations. Typically a large battery (usually a 36-Volt NiMH) stores electricity to help restart the engine when the driver releases the brake pedal.
As an example the Saturn Vue Green Line uses this system to gain a respectable 20% gain in fuel economy over the non-hybrid Vue.
