Having conquered portable applications such as cell phones and laptops that have relatively modest power demands, Li-ion batteries continue to migrate into higher-power applications. Two recent announcements from battery manufacturers Valence Technology and Saft illustrate the progress that larger Li-ion battery packs—with capacities of 40 Ah or more—are making in ground-based transportation and space applications.

Valence Technology (www.valence.com) of Austin, Texas has announced that Oxygen S.p.A. (www.oxygenworld.it), a provider of electric transporters, has placed orders for Valence’s U-Charge XP battery systems, which are based on company’s Saphion large-format lithium-ion technology. The Italian company selected Valence batteries to power a new line of electric scooters designed for delivery fleets across Europe. Oxygen’s initial fleet deployment will start this summer with a major European Postal Service.

Oxygen’s electric transporters are designed for businesses and commuters who require reliable and economical transportation, but are ideal for delivery services in congested urban areas. Valence’s Saphion technology has enabled Oxygen to deliver a solution where their customers can make deliveries for the entire daily route without having to recharge the battery.

Oxygen will use the U-Charge XP Power System (Models U24 and U1) in its cargo scooters. The Oxygen electric scooters feature advanced technologies such as brushless motor, electronic engine control and regenerative braking to recharge the battery. Driving range is up to 85 miles.

The U1 is a 12.8-V battery that specifies a 40-Ah capacity at a C/5 discharge rate. This battery measures 7.75 in. x 5.2 in. x 7.2 in. and weighs 13.4 lbs. The U24 is a 12.8-V battery with a 100-Ah capacity, measures 10.24 in. x 6.8 in. x 8.6 in., and weighs 34.5 lbs.1

“Oxygen is another example of an OEM which has moved from evaluation/prototyping to production level deployment of our battery systems. 2 We expect more companies will embrace the benefits of lithium-ion in large format applications and select Valence given the safety and benefits of Saphion technology,” says Dean Bogues, president of worldwide sales & marketing at Valence Technology.

Meanwhile, Saft (www.saftbatteries.com) , which has US headquarters in Maryland, recently won an award from Boeing (www.boeing.com) to supply Li-ion batteries for the Mobile Satellite Ventures Satellite program. The multi-million dollar contract will mark Saft’s largest U.S. commercial satellite contract for Li-ion batteries and the first commercial satellite program using Li-ion technology for Boeing. The satellites will be among the largest and most powerful ever built and will be provided to Mobile Satellite Ventures (MSV) for an advanced commercial telecommunications network.

Saft will become Boeing’s designated source for Li-ion technology for two of the Boeing-built GEO-Mobile MSV satellites, in which they are expected to provide up to 18 years of battery life. The rechargeable batteries will be installed on the satellites to power critical systems. Saft’s VES140 40-Ah Li-ion cells (arranged in a 6P12S configuration) will provide a compact, weight-saving source of on-board power to ensure continuous, reliable operation of the satellites at times when their solar panels are in eclipse. The VES140 has a nominal voltage of 3.6 V, while the 6P12S batteries have a nominal voltage of 50 V. These batteries will be placed in series for the 100-V bus in Boeing’s satellite.

Despite their similar nominal voltage, the VES140 cells differ greatly from Li-ion cells used in laptop computers or other commercial applications. Space-grade cells, the VES140 can endure more charge/discharge cycles than commercial cells. The VES140 cells are based on the same electrochemistry as Saft's Li-ion cells for automotive applications. In order to reliably deliver reserve power for 18 years, the satellite batteries must be built from the best materials and must be designed and built with specialized expertise, according to Saft.

Saft’s Li-ion batteries allow Boeing and MSV to decrease the satellite’s weight significantly versus the previously used nickel-hydrogen battery chemistry. This approximately 30% to 50% weight savings on the battery, which results from a specific energy of 120 Wh/kg, allows the satellite manufacturer and user to dedicate more of the satellite’s crucial mass to the payload.

"Saft has been working with Boeing for many years and this award is the result of a group effort to get Li-ion batteries on-board their GEO-Mobile satellites," said John Searle, Saft CEO. "Li-ion is the ideal battery technology for space applications due to its superior performance and light weight. We believe this award strengthens Saft's position as a leading supplier of Li-ion battery systems for the U.S. space market."
Boeing will build the GEO-mobile satellites, based on its powerful 702 infrastructure, for the world’s first commercial mobile satellite service using both space and terrestrial elements. The network, based on MSV's patented Ancillary Terrestrial Component (ATC) technology, combines the best of satellite and cellular technology. It will deliver reliable, advanced and widespread voice and data. Each spacecraft will supply 11,000 W of power.

1. A datasheet for the U-Charge XP Series batteries is available online at www.valence.com/pdffiles/U-Charge%20XP%20DS%20Jan06.pdf

2. Oxygen’s order of evaluation/prototype units was reported in “Batteries Take to the Road in Electric Scooters,” PETech Times, October 5, 2005, available online at http://powerelectronics.com/batteries-electric-scooters/