California has passed legislation that will ban the sale of new gas- and diesel-powered “small off-road engines” (SORE) used in turf care equipment such as lawn mowers, leaf blowers and chainsaws, beginning January 1, 2024.
California’s law, which is intended to reduce air pollution, will likely be similarly adopted throughout the U.S.
Manufacturers of turf care products are quickly moving to EV systems.
THE OEM PROBLEM
QUICKLY ENGINEER A BATTERY-ELECTRIC FAIRWAY MOWER
A leading turf care product manufacturer, aspiring to quickly bring a battery-electric fairway mower to market, set an eight-week schedule to introduce a preproduction prototype at the 2022 GCSAA Conference and Trade Show in San Diego. The engineering team faced an aggressive timeline.
THE ELECTRICAL CONTROL DESIGN CHALLENGE
ENGINEER A RIGHT-SIZED ELECTRICAL CONTROL SYSTEM FOR CONVERSION TO EV
The OEM determined to convert its popular 12V/48V hybrid diesel engine-powered fairway mower to EV.
The necessary electrical control modules — a Motor Controller Unit (MCU), a Power Distribution Unit (PDU) and a CAN Display Unit (LDU), all supplied by Marlin Technologies — were already on the OEM’s diesel engine-powered fairway mower platform. The design challenge for Marlin was a matter of converting the modules for EV as an appropriately sized integrated electrical control system, to achieve adequate and efficient transfer, conversion, consumption and utilization of electrical and mechanical energy.
APPLY EV EXPERIENCE AS A DEDICATED PARTNER
Marlin Technologies partners with OEM customers to enhance the performance of their products by designing and manufacturing innovative and cost-effective electronic control solutions.
The turf care OEM chose Marlin to convert its 12V/48V hybrid diesel engine-powered fairway mower to EV because Marlin’s team is knowledgeable about that particular mower and also provides support for the OEM’s other products. Importantly, Marlin’s team had proven experience with electric vehicles prior to this challenge.
The OEM project leader spearheading the conversion asked Marlin sales manager Jim Schoenauer how Marlin would go about providing an electrical control solution to convert the OEM’s diesel mower to EV and create a working prototype within an eight-week deadline.
Schoenauer captured all the requirements and estimated Marlin’s hours of engineering time to achieve the conversion. He formulated a quote for the OEM, and they quickly provided a purchase order green-lighting Marlin’s team to begin the work.
Marlin assigned a dedicated development team to address the challenge. Working collaboratively, the OEM’s team and Marlin’s team held weekly status meetings to accommodate the very fast turnaround required. Marlin’s team defined and broke down the problem into individual pieces for each of the electrical control modules, which enabled them to determine the hardware and software updates necessary to increase the mower’s electrical system from 12 volts to 48 volts and right-size the modules for the EV application.
Marlin has developed so many electrical control solutions for so many applications that its engineers are always ahead of the game — not starting with a blank piece of paper in addressing challenges. Our starting point begins with either our library of previously developed modifiable custom products, or with our customizable M-Flex® stock products. Marlin uses its entire library of circuits along with our electrical engineering expertise to bring the best in terms of technology, knowledge and proven experience to our customers’ applications.
Because our engineers understand the turf care market, conversion to EV and the requirements
of electrical control systems, this challenge was a natural fit for Marlin.
AN INTEGRATED ELECTRICAL CONTROL SYSTEM RIGHT-SIZED TO THE OEM’S EV APPLICATION
Because Marlin Technologies’ custom modules are powerful and flexible enough to handle a variety of applications, its engineers were confident that the Marlin electrical control modules installed on the OEM’s diesel engine-powered fairway mower could be utilized for the EV conversion, with only a hardware upgrade and software changes being required.
The Marlin Technologies modules adapted as the integrated electrical control system of the new EV fairway mower are:
All of the power required for the battery-electric fairway mower funnels through the Power Distribution Unit (PDU). The PDU acts as a main service for the vehicle. It provides the current for individual loads such as lights, electric motors, actuators, and the mower reels. PDUs are even more critical for the EV mower application because they deliver electric power for the four-wheel drive and the cutting reels which were previously powered by a diesel engine. Marlin’s PDU has spare capacity for the existing application, so no additional hardware was required for the conversion. However, the Marlin team provided software updates to the PDU to convert from the diesel mower’s 12-volt system to the 48-volt system required for the EV mower.
The Motor Controller Unit (MCU) controls the electric driver motor for the four-wheel drive fairway mower and all of the machine’s electric reel motors. The MCU underwent the most extreme conversion because it required a hardware upgrade to expand its capability to control both the individual mower reels and the drive controls for the multi wheel drive. Marlin provided a major software update to upgrade the programming language. The new system now uses CAN messaging to control the traction motors, reel motors and actuators.
The CAN Display Unit (LDU) is the human-machine interface that provides the mower operator with critical information and actuates the various functions to properly run the mower. The LDU presents vehicle diagnostics such as battery voltage, runtime, oil pressure and engine coolant temperature. It also shows service information such as fault codes, service requirements, vehicle status and IO diagnostics with easy daylight viewability. Marlin provided the necessary software updates to convert its off-the-shelf M-Flex® 4.3” CAN Display from a 12-volt system to a 48-volt system.
Marlin delivered the right-sized integrated electrical control system within the eight-week deadline to introduce the EV prototype at the 2022 GCSAA Conference and Trade Show. The environmentally friendly mower was a hit of the show. Marlin and the OEM are now working on the production run of the new battery-electric fairway mower.
ENVIRONMENTALLY FRIENDLY AND COST EFFICIENT
SPEED AND EFFICIENCY TO MARKET
PRODUCTION EFFICIENCY, ELECTRICAL SYSTEM DEPENDABILITY AND BETTER END-USER EXPERIENCE
Marlin is prepared for the future.
EV is the future. We are seeing it not only in turf care. We are seeing it in the refuse market for garbage trucks, and we are beginning to see it in construction and other industries.
With projects like this EV conversion case study, Marlin Technologies is helping to create
the future for a sustainable environment.
ABOUT MARLIN’S ENGINEERS
Marlin’s field service engineers are electrical engineers who are trained for the application and have thousands of hours of experience on the equipment. They know the equipment extremely well, often better than the OEM does. They are experts not only on Marlin’s equipment, they are experts on the equipment of our OEM customers as well.