Webasto Delivers Battery System for Zeus EV Chassis

The single-source battery, software and thermal management solution enables Zeus to size for capacity and integrate for both range and work functions.

May 27, 2022

Ryan Gehm

Zeus Electric Chassis’ first customer is the Sacramento Municipal Utility District. (Zeus)

Electric work trucks are beginning to roll off the line at Zeus Electric Chassis’ production facility in White Bear Lake, Minnesota. Zeus is providing the Sacramento Municipal Utility District (SMUD) with five built-to-spec Class 5 EVs, four of which are being upfitted with truck bodies from the Knapheide Manufacturing Co.: an electric stake truck; an electric open-body service truck; an electric closed-body service truck with crew cab; and an electric dump truck.

Taylor Hansen, president and CEO of the Customized Solutions – Americas Region, Webasto Group. (Webasto)

Knapheide is not the only company Zeus has worked with since early in its chassis development process. Webasto supplies a single-source battery, software and thermal management solution used for the Zeus EV chassis. “We worked closely with Zeus’ engineers to provide a highly flexible battery system that will evolve with Zeus’ vehicle lineup and business,” Taylor Hansen, president and CEO of the Customized Solutions – Americas Region, Webasto Group, told SAE Media. The relationship with Zeus began at an industry tradeshow in 2019, she noted.

The Webasto Commercial Vehicle (CV) Standard battery, battery-electric thermal management unit (eBTM), and the vehicle interface box (ViB) that contains the power distribution system and battery management with DC fast-charge capability, are included in the system. The battery packaging is crash-tested and validated up to 100 kN (22,480 lb) and is rated IP67 for water tightness. A single CV standard battery is rated at 400 VDC and 35 kWh, but depending on the configuration, it can become an 800-VDC system with up to 350 kWh when utilizing the ViB.

Webasto’s relationship with Zeus began at an industry tradeshow in 2019. (Note: The work truck EV chassis shown is not the Zeus platform.) (Webasto)

The eBTM is a standalone, plug-and-play system designed to ensure optimal functioning of water glycol-cooled battery packs. “It ensures long-term ideal battery cell performance by actively regulating the temperature of the battery packs,” Hansen said. Using sophisticated computer simulations, factors such as duty cycles, climate and geographies can be used to determine the appropriate number of battery packs and the type of thermal management needed to optimize battery performance and lifespan.

Webasto’s thermal management system uses both active and passive cooling, as well as electric fluid heating and heat pump systems. Within the battery pack, the modules also include desiccant cartridges that reduce condensation, integrated thermal runaway detection sensors and state-of-the-art pressure equalization monitors for added safety.

SMUD vehicles in production at Zeus’ White Bear Lake facility in January 2022. (Zeus)

The main benefit of the system, Hansen said, is that it allows the customer flexibility to scale up or down using the same components, which ultimately helps keep costs under control. “The Webasto battery solution enables Zeus to size for capacity and integrate for both range and work functions,” she said. “This system flexibility and the Zeus holistic integration approach allows fleets to field medium-duty EV work trucks that meet their specifications and perform the work for an 8- to 10-hour day.”

The Webasto battery system is designed for a wide variety of vehicle types, Hansen noted. These can include light-duty, heavy-duty, off-highway as well as special-purpose vehicles for emergency services, police and security organizations. The scalable solution also can work with commercial fuel cell systems. “Given that it is plug-and-play, our product line allows integrators to optimize the fuel cell system for its specific application,” she said.