In an age when the demands on
lithium-ion battery systems are increasing, the need for flexibility, speed and
cost effectiveness cannot be underestimated.
Production on projects in Cedar Park will
begin in September, with series battery systems expected to be delivered from
the end of the month onward. In production will be the company’s new modular
systems for prismatic cells. Frers states, “On the one hand, we integrate NMC
(nickel manganese cobalt oxide) cells in new 24V Li-ion modules. Weighing only
18kg, they are very reliable for up to 6,000 cycles, while having a good energy
density (135Wh/kg or 316Wh/l) with regard to their size and weight.”
The
high-performance battery systems produced at our Cedar Park works in Texas are
largely made using components of American origin, and therefore fulfil the
local-content requirements of the “Buy American” Act of 2009.
For certain applications, such as its next US
project, which will be for the city of Dayton, Ohio, batteries are required to
have very long possible lifetimes, “so we’ve developed battery systems that
will live for nearly as long as the whole bus – 10 years or longer, assuming
wise use” adds Frers. “For these applications, LTO (lithium titanate oxide)
cells are the optimal solution. LTO cells are stable for more than 10,000
cycles and, in the right usage, even 20,000 cycles.” The LTO cell’s energy
density is 89Wh/kg or 172Wh/l.
As part of the Ohio project, Voltabox will
provide a dual-mode trolley bus battery system. Its nominal voltage level will
be 600V, with a total capacity of 61kW/h. Comprising 1,512 LTO cells per system
(42 modules, each with 36 cells), the configuration will enable up to 24km battery-driven
distance with a 12m bus, with all 43 seats taken. Impressively, in this
application, there will be up to six load cycles per day, in up to 18 operating
hours per day.
Vossloh
Kiepe, the producer of traction equipment for electrical vehicles, will be
using the high-performance systems from Voltabox as back-up power supplies for
some 200 new electric trolleybuses in Seattle and San Francisco.
A further application for which Voltabox’s
modular system for prismatic cells is ideal is vehicles used in material
handling, such as forklifts. Both 24V and 48V Li-ion batteries, traditionally
the standard in these applications with the lead acid batteries that have been
favored until recently, are employed. Frers says, “Two, four, six, eight and,
in some cases, 10 of these modules will be packed in special containers,
combined with an external master BMS unit that we produce, and a display unit
will be added to show the parameters of the battery. Our maintenance-free,
high-performance battery systems will ensure the robustness and quality of the
vehicles, which are key components of any modern, smooth-running logistics
operation.”
Voltabox
develops battery systems based on two different types of cell-technology. Both
technologies – iron-phosphate and nickel-manganese-cobalt-oxide-based – each
offer their own distinct advantages, when it comes to the corresponding
applications, which we have enhanced and fine-adjusted in the course of our
development work.
Frers is also keen to point out that
Voltabox is not limited to the industries on which it has already made its
mark. “With these new modules based on prismatic cells,” he concludes, “we have
a ready solution for car and motorcycle batteries. In fact, we’re working on
exciting projects in these areas that, for now, will remain confidential.”
