USABC Progress On NiMH Batteries is Electrifying
24 September 1999
USABC Progress On NiMH Batteries is Electrifying
Contract With SAFT Completed; New Contract Signed
SOUTHFIELD, Mich., Sept. 24 -- The United States Advanced
Battery Consortium (USABC) has completed work with SAFT under their nickel
metal hydride (NiMH) battery development contract. The module developed has
increased performance over previous electric vehicle (EV) modules, further
enabling zero-emission vehicles in the field, which is good news for the
environment.
The final NiMH module design meets all of the goals and targets specified
in the contract. It is a single 12-volt unit that incorporates a resealable
vent in each cell to guard against high gas pressure developing in the event
of an overcharge. The module also includes liquid thermal management and a
restraining system to prevent the module from bulging during cycling. The
specifications of the final module can be found in table 1.
"This has been one of the most successful USABC programs. All the program
goals were achieved and SAFT has begun delivering production modules to
DaimlerChrysler for their EPIC Electric Minivan," said Thomas J. Tartamella,
the USABC SAFT NiMH program manager. "As the USABC looks to long-term
technologies to meet OEM EV battery requirements, NiMH will be the mainstay
advanced EV battery technology."
During Phase I of the project, USABC developed an advanced NiMH battery
for EV propulsion as part of a 39-month, $20.8 million contract, which ran
from December 1992 through March 1996.
Phase II, which focused on cost reduction and further performance
improvements, was a 32-month, $11.05 million contract and ran from April 1996
through November 1998. During the course of the Phase II program, a 35
percent module cost reduction was realized over the final Phase I module.
Four battery packs incorporating the final module design were delivered in
two configurations to USABC by SAFT as part of this contract (see table 2).
Three 30-module packs were delivered for EV testing and one 34-module pack was
delivered for utility applications.
While the USABC and SAFT have made a lot of progress on NiMH batteries,
cost and size issues remain. With the technology available today, further
size and cost reductions are unlikely. For this reason and because these
batteries have already been commercialized, the USABC is moving on to other
batteries technologies, including lithium-based batteries.
On Feb. 1, 1999, the USABC entered into a 36-month, $14.4 million dollar
development contract with SAFT America, Inc. to develop their lithium-ion (Li-
Ion) battery technology for EV propulsion batteries. The SAFT Li-Ion
technology aims to exceed the USABC mid-term goals and reach the
commercialization goals. The program is divided into three distinct phases
and will result in delivery of full-size battery packs complete with all
necessary control systems.
USABC pursues the development of advanced energy storage systems capable
of providing future generations of electric and hybrid vehicles with
significantly increased range and performance -- at a cost competitive with
gasoline-powered vehicles. Its members include DaimlerChrysler, Ford Motor
Co., General Motors Corp. -- under their United States Council for Automotive
Research (USCAR) umbrella -- EPRI (representing electric utility companies)
and the U.S. Department of Energy.
USABC is one of 12 consortia under USCAR, which coordinates cooperative,
pre-competitive research projects of DaimlerChrysler, Ford and GM.
Other USCAR research deals with safety, emissions, alternative power
sources, lightweight materials, recycling, electronics, and -- under its
Partnership for a New Generation of Vehicles effort with the government,
suppliers and universities -- technologies that can lead to more fuel-
efficient vehicles. For more information, visit USCAR's Web site at
http://www.uscar.org
Table 1
SAFT NiMH Module
Module nominal voltage 12V
Module dimensions (LxWxH) 390 mm x 120 mm x 195 mm
Module rated C/3 capacity : 106 Ah
Module typical C/3 capacity : 111 Ah
Module typical weight :
(with coolant and restraining system) 19.8 kg
Module typical specific energy : 70 Wh/kg
Module typical energy density : 152 Wh/liter
Module rated specific power :
(80% DoD, 350 A max and 8 V min) 150 W/kg
Cycle Life (DST120 to 80% DoD @ RT) 1000-1400 cycles
Table 2
Electric Vehicle Pack Utility Peak Shaving Pack
30 modules 34 modules
Pack C/3 rated energy 40 kWh 45 kWh
Pack nominal voltage 360 V 408 V
Typical total weight of
modules 670 kg 757 kg
(603 kg of modules) (683 kg of modules)
Overall dimensions (*) 925 mm x 2005 mm 925 mm x 2249 mm
x 229 mm x 229 mm
Maximum currents 350 A 30 sec, 220 A continuous
Pack maximum power (350 A,
30 sec, 80% DoD, 0.8 V/cell) 90 kW 102 kW
(3 kW per module) (3 kW per module)
* : dimensions include tray brackets and attachment points