Five blogs of Dave
Looking back at the future: Saab 9-3 epower
by, 13 June 2012 at 18:41 (756 Views)
Now that NEVS is set to own the Saab car company and plans to build a 9-3 electric car while it develops a car based on the Phoenix platform, a look at the past may give hints of the future.
In 2010, Saab issued a press release. This is an excerpt.
Targets to be verified include a projected driving range of approximately 200 kilometers through the use of high density energy storage in lithium-ion battery cells.
The Saab ePower is the first electric vehicle from Saab and is a result of a co-operation between Saab Automobile, Boston Power (batteries), Electroengine in Sweden AB (battery management system), Innovatum (project management), Power Circle (Sweden’s electric power industry trade organization) and the Swedish Energy Agency (partial financing).
Under the hood is a 135 kW/184 hp electric motor driving the front wheels through a Saab in-house designed single speed transmission with state of the art efficiency and noise & vibration levels. Instant torque enables zero to 100 km/h acceleration is just 8.5 seconds, together with a top speed of 150 km/h.
The compact yet powerful 35.5 kWh lithium-ion battery pack is accommodated in a modified floor-pan, mainly in space within the car’s wheelbase previously occupied by the exhaust system and fuel tank. This enables an optimum weight distribution and excellent driving dynamics similar to those of a standard SportCombi.
Electro-hydraulic power steering is used and the cabin is equipped with full air conditioning, via a compressor powered by the battery pack. A separate 12-volt battery, for the lights and cabin ancillaries, is also charged from the battery pack via a current transformer.
The Saab 9-3 ePower’s projected driving range of approximately 20 kilometers 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.
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 -30ºC, at least 10ºC 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 re-charge cycles equivalent to about ten years average use. It can be fully recharged from a domestic mains supply in about 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.
From: Saab 9-3 ePower - Saab
There may be a typographical error since it is unclear if the range is 20 km or 200 km. The battery is not very large. In comparison, the Ford Focus is about to be released and has a range of 75 miles (greater than 100 km).
Inside Saab, a blog written by Steven Wade in his official capacity as a Saab employee, also wrote about the Saab 9-3 epower. Below is an excerpt.
The Saab 9-3 ePower, the basis for these test vehicles, uses a lithium-ion battery pack and a new, advanced battery management system to deliver 200 kilometers of zero-emissions driving with the convenience of a full sized family wagon.
A view of the battery case inside the vehicle. It goes down the middle of the car, allowing for optimal weight distribution and forms a divider between the two rear seats.
From: Saab Zero Emissions fleet under construction | Inside Saab by Steven Wade