eVTOL from Lilium
with support from AVL
he development of eVTOL for the urban air mobility
of the future meant that Lilium needed to design an
innovative battery system that meets the high technical
requirements and certification specifications of the aviation in-
dustry in terms of mechanical, electrical, and chemical design.
However, since there are no established testing requirements
for batteries in the aviation industry at present, the company
was faced with the task of developing its own product vali-
dation methodology for its new battery design. The complex
challenge called for the best test environment available, which
is why Lilium opted to collaborate with AVL.
Gradual Implementation of the AVL Test Facility
AVL designed a comprehensive test facility to be implement-
ed in several phases. The focus is on developing customized
battery test equipment for cell, pack, and system tests that
meet the specific requirements of these extraordinary com-
ponents. This equipment has been specially adapted to the
requirements of cellular chemistry and aircraft design, and
facilitates extensive testing, which also goes beyond the limits
of real-world use. Special attention is paid to the high current
flows during eVTOL’s take-off and landing procedures, as well
as to handle complex redundancy methods of the pack units.
Minimizing Total Cost of Ownership, Maximizing Transparency
of Costs
The test facilities developed by AVL were implemented grad-
ually, taking into account synergy effects for other projects
and optimum operational usability of the equipment. This
minimized the total cost of ownership (TCO) and maximized
the transparency of costs. A dedicated testbed building with
a bunker for battery misuse tests was also planned. The con-
cepts and design specifications form the foundation for the
final implementation of the test facilities at the Lilium campus
near Munich.
The Importance of Collaboration for the Success of the Project
The collaboration between Lilium and AVL in developing a
test environment for eVTOL was pivotal to the success of the
project. The use case demonstrated that aircraft battery cells,
packs, and systems can be validated using the AVL battery
test systems (AVL E-STORAGE SiC™ battery tester, AVL PUMA
2™ battery automation system, AVL cell/battery pack/battery
system test chambers, and AVL safety system). With the
implemented operating modes, all jet-specific parameters can
be tested in real-world and artificial conditions.
German aviation startup Lilium has caused something of a sensation
with its electrically powered aircraft that takes off and lands vertically
(eVTOL). To test the new battery developed for the high energy
demand, the company turned to AVL’s expertise.
Photo: Lilium
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