Large size hybrid electric trucks from Volvo

The Volvo Group unveils viable new hybrid technology

Today, the Volvo Group presents an efficient hybrid solution for heavy vehicles, which offers fuel savings of up to 35 percent. “We envisage opportunities to accelerate developments in commercially viable hybrids for heavy vehicles. This can be significant for both our customers and for the environment,” says President and CEO of Volvo, Leif Johansson.

The Volvo Group’s hybrid concept provides maximum fuel-saving effects on routes with frequent braking and accelerations, for example in refuse collection, city bus traffic and city distribution. Calculations indicate that fuel savings can amount to 35 percent. Maintenance costs for vehicles can also be reduced through reduced wear on the braking system.

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

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This is interesting, and there are several advantages. This is meant for heavy trucks, and one complaint of the typical heavy truck is the noise it makes.

The Volvo hybrid drive train, I-SAM (Integrated Starter, Alternator, Motor), is said to have several useful features:

• Allows the truck to accelerate under electric power alone allowing such a truck to drive quietly.
• the diesel engine can be automatically switched off when the truck stops to make deliveries, pick up loads or pauses at traffic lights
• Auxilliary functions like the air conditioning can be run independantly of the main engine.
• The combined electric and diesel drive system allows for a smaller main engine.
• They made sure the main engine can run from biofuels.

What's even more interesting is the battery system, by EFFPOWER. It's a lead-acid battery made in a way that's highly suitable for hybrid vehicles. It offers a high power density (for lead-acid batteries) at low cost, and a tremendous number of charge/discharge cycles under shallow discharge.

However the battery technology might not be good in a pure battery EV. Battery EV's see deep discharges, under which the large number of shallow discharge cycles is not an advantage. Shallow discharges are different in nature from deep discharges.

More information on hybrid electric vehicles

Find more at Green Car Congress