Power and Potential

Eaton and BAE Systems collaborate on 3:1 solution for medium and heavy-duty trucks

The assignment was simple: compare a CL7 Freightliner M2 retrofit—with a BAE Systems propulsion solution and an Eaton MD 4-speed EV transmission—to a similar sized truck with an ICE. Sure, you can pop the hood, examine the interior, and ask a few questions—which we did during a June 2024 event at Eaton’s Proving Grounds located in Marshall, MI—but the fun part came when we took both vehicles out on the test track to see how the EV truck handled on turns, inclines and at top speeds versus its ICE counterpart.

“We see an exciting opportunity here to reduce complexity, cost, and improve reliability and efficiency of next–gen EV trucks with this solution,” said Justin Hopkins, product director, e-powertrain at Eaton.

Experience Matters

BAE Systems has more than +25 years commercial vehicle experience including the development of a power-dense electric motor and advanced silicon carbide/gallium nitride power electronics suite as well as two decades of experience developing and integrating electric propulsion systems. If that’s not enough the company provides some of the world’s most advanced defense, aerospace and security solutions.

Tom Webb, director of business development and strategy at BAE Systems described the collaboration as “focusing on simplification, serviceability and an effort to meet EV goals now and in the future.”

Eaton’s heavy-duty 4-speed EV transmission was named a 2024 Automotive News PACEpilot Innovation to Watch award winner.

“When I first started, we had about 12 people working on pilot orders at BAE Systems and now we have 350+ people and have been profitable for over two decades. We have shipped (and support) roughly 18,000 systems—99 percent are in city buses not trucks, but to give a little respect to city buses, particularly in New York City, for example, they have a pretty severe duty cycles.”

Eaton is an intelligent power management company dedicated to improving the quality of life and protecting the environment. They offer heady duty and medium duty 4-speed EV transmissions that deliver class-leading performance, superior acceleration and gradeability with advanced efficiency for the EV system.

Together, they provide +125 years combined experience in commercial vehicle technology with more than 5 billion revenue miles in electrified commercial vehicle products. Engineers from both organizations examined Gen 1 EV trucks and determined they have a high part count, many interconnects and lots of wiring. “This not only adds expenses, but also compromises efficiency,” Hopkins said during the event.

Brian Kovalchick, senior technician at BAE Systems, reveals the space savings available under the hood of the test vehicle.

Notes from the Eaton/BAE Systems Test Drive Event Integrated motor/gearbox Easy to install 4 speed AMT for CL5-8 Superior performance Power-dense e-motor High torque for gradeability and top speed Industry leading electronics SiC/GaN Improved efficiency and more range High power density reduces size and weight Multi-functionality Charging and battery interface E-ancillaries and ePTO Truck retrofit: CL7 Freightliner M2; BAE Systems propulsion solution; Eaton MD 4-speed EV transmission; Forsee Zen 77 Plus batteries; Meritor rear-axle with 3.9:1 ratio. Key metrics: 33,000 lb. Gross Vehicle Weight Rating (GVWR); Payload capacity of >18,000 lbs.; 230 kWh of electrical energy storage; top speed of 70 mph (electronically limited); starting grade at GVWR of >21 percent; Efficiency at GVWR of 1.1 kWh/mile. Performance vs. ICE: Improves 0-20 mph acceleration rate by 2x; Reduces 0-50 mph acceleration time by >20 seconds; Curb-weight increase of only 1,400 lbs.

EV Evolution

Eaton and BAE Systems engineers were tasked with reducing the cost, size, weight and complexity of the EV truck while increasing its reliability. The solution uses a multi-speed EV gearbox coupled with a compact high efficiency motor to deliver both speed on highway and speed on grade—most commercial EVs cannot deliver both. Bill of Material is significantly reduced from typical EV solutions by highly integrating all major EV drive and auxiliary functions. Potential applications for this solution include pickup and delivery, bus, municipal, port drayage, yard tractor and regional logistics.

“While Eaton’s electrical experience is wide and robust it’s of interest to note that the company is now offering charging solutions that complement our on-vehicle powertrain solutions,” Hopkins said. “We’re not doing electric motors or any accessory power electronics like BAE does, so this collaboration makes a lot of sense.”

Developed to aid efficiency, Eaton’s purpose-built medium-duty and heavy-duty EV transmission helps to increase range, grade capability and acceleration for commercial electric vehicles. Leveraging decades of experience, this EV transmission is based on proven, robust and efficient layshaft architecture and allows for use of a smaller motor.

Eaton’s new 4-speed transmissions provide superior performance on grades and acceleration for electrified commercial vehicles while offering more flexible gear ratios compared to competitive technologies. The compact 4-speed transmissions also improve system efficiency, enabling longer vehicle range and battery life.

“These transmissions were developed based on existing Eaton ICE technology that we adapted to the EV market,” Hopkins said. “Our goal was to make the shift smooth and quick, but there’s tradeoffs, right? If you make it too quick, it could be jerky. We want to make sure we’re doing the right thing for the application.”

BAE Systems provided the electric motor and power electronics for the test vehicle.

A 4-speed transmission is unique for both commercial and light vehicles but Hopkins stated that because the motor has a larger range of operation, you don’t need as many speeds.

Additionally, the heavy-duty 4-speed EV transmission was named a 2024 Automotive News PACEpilot Innovation to Watch at an awards ceremony in April. This recognition acknowledges post-pilot, pre-commercial innovations in the automotive and future mobility space.

Ride and Drive

The Class 7 demonstration vehicle checked all the boxes for simplifying electric drive systems.

First impressions? It’s uncanny how much room there was under the hood. By emphasizing size and weight reduction and moving the battery pack toward the back of the truck, there’s so much empty space up front. I’ve never seen fewer components in a vehicle or less high voltage orange cables running amok.

The handling and acceleration on the test track were significantly better in the EV vs. the ICE commercial vehicle. It took turns and shifted smoothly, accelerated generously and was an absolute comfort between 60 and 70 mph.

With a hill holding function on the powertrain, I was able to take my foot off the accelerator on steep inclines and the EV truck would hold on to the grade. I imagine this would be an extremely beneficial feature for a delivery driver in heavy traffic in Pittsburgh or San Francisco.

The ICE counterpart performed as expected.

The steering wheel shook harder during acceleration and the overall handling whilst taking curves was nowhere near as comfortable as the EV. Honestly, it felt like driving an old truck as opposed to a shiny, spectacular new EV vehicle fresh off the lot.

As my first drive in an EV commercial vehicle, I was impressed by all the bells and whistles on the inclines as well as the shifting architecture on the test track. Eaton and BAE Systems have delivered on simplifying and reducing the weight of the motor and battery packs. This test vehicle hints at what fleet vehicles could look like moving forward. I thoroughly enjoyed my time behind the wheel.

The empty space under the hood was noteworthy in the EV test vehicle compared to the ICE truck.

What We Learned

It’s one thing to debate about the differences between electrical and ICE vehicles, but I believe if more people had an opportunity to drive an EV and its ICE equivalent back–to–back, you’d see how far the technology has come and what the future actually holds for the transportation industry.

I circle back to discussions at the CTI Symposium earlier this year. Many experts in the automotive, truck, construction and off-highway sectors understand the pushback when it comes to meeting sustainability and CO2 requirements. They realize the infrastructure challenges, the costs, and the market fluctuations. Everyone hears all the noise in politics as well as the media. Regardless, these engineers continue to roll up their sleeves and find the best EV solution for the application.

“Buses—city and school—are doing really well in the EV space,” Webb added. “We hope to see similar results in commercial vehicles and material handling. There are challenges to overcome, but it’s an exciting time to be a part of the electrification movement.”

eaton.com/us/en-us/products/emobility.html