Lithium-ion is emerging as automakers' favorite battery technology for electric vehicles, according to French battery maker Saft.
In European Union-sponsored tests in Stuttgart, Chrysler Voyager EPIC minivans with 45 Saft lithium-ion battery modules on board traveled 200km before recharging was required.
The EPIC, or Electric Powered Interurban Commuter, is a standard Voyager with a special chassis for batteries and electric motor.
Meanwhile, in Turin, Fiat Seicento Elettra minis with 20 Saft battery modules had a range of 140km.
A combination of battery cell design and systems integration improves vehicle performance substantially, Saft automotive communications manager Catherine Jouatel told an international electric vehicle symposium in Berlin last month.
Saft has already started small-scale industrial production of high-energy lithium-ion batteries for pure electric cars and hybrids.
'With their reduced weight and volume, Saft's lithium-ion cells represent a major breakthrough,' Jouatel said. 'Lithium-ion technology is the longer-term solution for electric vehicles and hybrids too.'
Saft worked with DaimlerChrysler and Fiat on electronics compatibility and battery integration.
'Results have been very encouraging, particularly in the crucial area of vehicle range - up to 200km in the urban cycle,' Jouatel said.
Saft research is focusing on thermal control for enhanced safety. New testing will involve fleets of 50 to 100 vehicles with other carmakers besides D/C and Fiat.
Saft of Paris operates plants in Nersac, in France's Bordeaux region. Saft began evaluating lithium-ion in 1996 as part of the Partnership for a New Generation of Vehicles, a program sponsored by the US Department of Energy.
That led to Saft developing high-power cells, 42-volt modules and full-size batteries. The devices are aimed at meeting automakers' requirements for specific power, cold-cranking capacity, cycle life and longevity.
Lithium-ion modules are typically 70 percent lighter than a comparable set of lead-acid batteries, with 80 percent recharge in one hour and full recharge in six hours, regardless of usage.
With the equivalent fuel consumption of 3.3 liters per 100km, the EPIC Voyagers running solely on lithium-ion power approach the US program's target of 2.9 liters per 100km.
Saft is developing medium-range batteries that balance power output with storage capacity suited to hybrids and stop-go-stop delivery vehicles. Saft's main competitors are Varta in Hannover, Germany, and Japan's Panasonic and Sanyo.
Nickel-cadmium and advanced nickel-metal hydride battery technologies are considered viable for current electric vehicles, and volume production of first-generation nickel-metal hydride batteries will start early next year.
But Saft says lithium-ion is better long term, despite costing a quarter to a third more than the other two technologies.
Ford confirmed its electric vehicle program dropped heated sodium-sulphur battery development. Ford tested Saft lithium-ion batteries in e-Ka prototypes three years ago.
PSA/Peugeot-Citroen and Renault are testing lithium-ion batteries in the Peugeot 106 and Renault Scenic.
Lithium-ion technology is already in widespread use for laptop computers and calculators. The power density, quick-charging and lightweight properties of lithium-ion batteries make them the power supply of choice for portable devices.
Lithium-ion technology also allows design flexibility. Cells can be any shape and located anywhere in a vehicle, said UK battery specialist AEA Technology.
AEA developed lithium-ion cells for the British army's new Bowman battlefield system. Flat and flexible batteries inside infantry body armor power sophisticated weapons and communications devices.