Saab 9-3 ePower

Side view of the Saab 9-3 epower SportWagon

Saab has become the latest car manufacturer to announce that it is developing an electric vehicle, with the Saab 9-3 ePower SportWagon.

Making its world premiere at the Paris International Motor Show later this month, the Saab 9-3 ePower all-electric family estate automobile is the prototype for a test fleet of 70 vehicles which will participate in extensive field trials in Sweden early next year.

The performance of the cars will be evaluated under a variety of real-world driving conditions as part of the development process for a purpose-built electric Saab vehicle. Targets to be verified include a projected driving range of approximately 124 miles through the use of high-density energy storage in lithium-ion battery cells.

Under the bonnet of the 9-3 SportWagon is a 184 hp electric motor driving the front wheels through a single-speed transmission. Instant torque enables zero to 62 mph acceleration in just 8.5 seconds, together with a top speed of 93 mph.

The 35.5 kWh lithium-ion battery pack is accommodated in a modified floor-pan, in a space occupied by the exhaust system and fuel tank on the standard 9-3 SportWagon.

The operation of the vehicle’s powertrain is controlled by a version of Saab’s own in-house Trionic 8 engine management system, with new software written for an electric vehicle application.

The Saab 9-3 ePower’s projected driving range of approximately 124 miles pushes out the boundaries for current EV performance. Key to its long range are battery cells which have an energy storage density substantially greater than the best currently used in EV applications. High energy density also contributes to a lower battery weight.

Saab battery packs

The battery pack has a capacity of 35.5 kW/h and is designed to operate with full power in ambient temperatures as low as -30şC, at least 10şC below the operating level of other battery packs on the market today. Another key benefit is the use of air, instead of liquid, cooling which contributes to lower cost and further weight-saving in the pack’s design.

The pack is intended to support recharge cycles equivalent to 10 years average use. It can be fully recharged from a domestic mains supply in three to six hours, depending on depletion status. Charging times can be greatly reduced if the voltage of the electrical feed is raised, as there is no limitation on the battery’s input capacity.

Test driving experience is expected to validate the performance of this advanced battery pack, which is designed to operate reliably within a full depletion ‘buffer’ set at only 12 percent of total capacity, a much lower operating margin than used in the management of other packs.

Its lithium-ion battery cells are also the first to receive a Nordic Ecolabel accreditation for their environmental safety and sustainability, which includes manufacturing processes.

The 9-3 ePower meets the high crash-worthiness standards that Saab applies to all its vehicles. The car’s power pack is located outside the occupant compartment in non-deformable structural zones, well protected and encapsulated. The battery management and monitoring system supports safe performance during normal driving and in crash conditions.

Test drivers

Hundreds of drivers and their families will be enlisted by Saab and its development partners during an extensive test driving and evaluation programme involving a 70-strong fleet of Saab 9-3 ePowers in central, west and eastern Sweden during 2011-12.

The Saab ePower project team in Trollhättan will monitor the performance of the cars across a wide variety of usage patterns and driving conditions. To log essential component data, all vehicles will be equipped with aircraft-style, black box recorders.