Volvo unveils viable hybrid technology for heavy vehicles

April 1, 2006
The Volvo Group presents an efficient hybrid system for heavy vehicles that offers fuel savings of up to 35%. Designated I-SAM, this hybrid concept provides

The Volvo Group presents an efficient hybrid system for heavy vehicles that offers fuel savings of up to 35%.

Designated I-SAM, this hybrid concept provides maximum fuel savings on routes with frequent braking and accelerations. Maintenance costs for vehicles can also be reduced through reduced wear on the braking system.

I-SAM consists of a combined starter motor, drive motor, and alternator, along with an electronic control unit. The system interacts with Volvo's I-Shift automatic gearshifting system. Batteries are recharged by the diesel engine and whenever the brakes are applied.

The electric motor offers smooth performance at low speeds, supplementing the diesel engine's performance as speed rises. This system allows the truck to accelerate under electric power alone.

“Thanks to the electric motor's capacity, the diesel engine can be automatically switched off when the truck stops to make deliveries, pick up loads, or pauses at traffic lights,” said Lars Märtensson, environmental affairs manager at Volvo Trucks. Auxiliary functions such as the servo pump and AC compressor are driven electrically in the hybrid truck instead of by the diesel engine.

Efficient interaction between the two power sources lets the vehicle be fitted with a smaller diesel engine without compromising on performance.

The Volvo Group is also participating in the development of a new type of battery, Effpower, based on lead-acid technology used in start batteries in vehicles. Through this new technology, power output has been doubled, while manufacturing costs for the batteries can be reduced. With Effpower, cost efficiency in electrical hybrids can be further enhanced.