Managing the thermal output of EVs

Modine and Bosch Rexroth will work together for the latter’s eLion product portfolio. (Illustration: Modine)

Bosch Rexroth and Modine are working together to electrify off-highway machinery. The latter will develop versions of its EVantage thermal management system products to complement the former’s eLION products in electrified off-highway equipment.

“With the increased shift toward electrified mobile machines, there’s a parallel need to manage the thermal output of those crucial components efficiently,” said Zifan Liu, Bosch Rexroth mobile hydraulics system engineer. “This partnership represents a concerted effort to effectively address that issue and present end-users with the most productive machine possible.”

Modine’s Advanced Thermal Systems has designed a fully integrated, liquid-cooled thermal management solution for the eLION portfolio. That portfolio currently includes a permanent magnet synchronous electric motor, electric inverter, onboard charger, DC-DC converter, power distribution unit, high voltage cables and a controller. As the market evolves, so has the eLION catalog.

“We offered every single component that is needed for those machines, except for the thermal system,” said Enrique Busquets, director, Engineering Systems and Components, Bosch Rexroth, Fountain Inn, S.C. “Therefore, Bosch-Rexroth has worked with a number of companies such as Ymer, Webasto, Wolfle and Eberspacher. In the United States, we have chosen Modine to build a machine prototype, which allows us to demonstrate how we can excel at thermal system development together. Working with Modine gives us a full system perspective that is quite favorable in many cases. It’s easier for customers to have a one-stop shop.”

Elgin Sweeper picked Modine components for its hybrid Pelican sweeper. (Photo: Modine)

Through the non-exclusive initiative, Modine will be able to leverage the capabilities of each company to help its own customers commercialize their electrified equipment.

“Some of them are working on a first-generation machine while others are already on their second generation and they’re working to optimize the design,” said Jeremy Shiflett, Market Development Manager, Modine Advanced Thermal Systems. “This collaboration gives them the opportunity to have two world-class companies come together and help them build that next generation product quicker. One thing we’re all seeing in the market today is that product development times have accelerated. It used to be that we would be happy with two to three years. Now these programs might get a year or two max before they want to be in production. You’ve got to be quick and agile.”

The EVantage Thermal Management System from Modine’s Advanced Thermal Systems business unit is designed to work seamlessly with the eLION portfolio to maintain optimal battery temperature, cool power electronics – and ensure operator comfort. For heating batteries and cab, the company uses a thin film-based 10 kW heater. The design is comprised of a complex layer system of heating elements securely and directly bonded to a heat-exchanging structure that is in contact with the liquid coolant.

Machine performance first

The first instinct for equipment engineers is to “start out talking about machine performance,” said Busquets. “When they understand how electrical systems are configured, they realize that the systems need to be cooled, just like with hydraulic machines. Today, most know they need a thermal system for the batteries, motors and inverters.”

But keeping the operator happy in the cab can add another layer of complexity – when batteries provide the power it is no longer a given that heat will be supplied by an internal combustion engine or even a hydraulic system.

“These workers are operating these machines for long periods of time,” said Shiflett, “and the goal is to keep them comfortable, so safety and productivity stay up.”

“In the beginning, giving the operator an HVAC system was almost disregarded,” said Busquets. “Machine performance was the focus. Now it’s simply one more system that is looked at within the whole machine architecture because it’s known to be a necessity.”

Modine’s Battery Thermal Management System with a liquid-cooled condenser, or L-Con BTMS, combines proprietary heat exchanger technology with smart controls and electronics designed to withstand dirty, harsh environments found in mining, construction, agriculture, specialty and transportation applications. (Photo: Modine)

For Modine, “something that we’re really excited about being able to demonstrate with Bosch Rexroth on this project is our complete EVantage battery thermal management system (BTMS),” said Shiflett. “ Beyond having a heater for the battery, we’re using the high-voltage heaters to also heat the cab. We’re optimizing the systems with enough capacity and a compressor that we can keep up with the cooling capacity on the battery while also offering passenger cooling at the same time.”

Finding the path

The two companies are currently working to convert a compact track loader that will help demonstrate the full system approach to keeping battery, electronics and humans comfortable.

Shiflett and Busquets said they’ve been busy helping customers find a path toward electrification that makes sense for every stakeholder – and operator comfort is regularly part of the discussion.

“When it comes to talking about the HVAC,” said Busquets. “I see it as an indicator of how serious the OEMs are, honestly. When you first talk about a prototype, you don’t really focus much on whether the operators are comfortable or not, you want to just get things working, and you want to prove that they have some efficiency or benefits. The fact that this is now being looked at and requested makes me think that technology and its implementation in the market is today at a higher level.”