Managing Medium/Heavy Duty Fleet Electric Vehicle Charger Communication Challenges

(Joseph Gottlieb, CTO, Tuesday November 10, 2020)

Another thing that medium/heavy duty (M/HD) electric vehicle (EV) fleet chargers have manage is a variety of different communications protocols and interfaces. These interfaces can be with anything from the vehicle to traffic scheduling systems to billing systems. Typical interfaces include CCS, CANBUS/MODBUS, ethernet, RS-485, USB, WiFi, and 3G/4G/5G cellular communications. To support these, M/HD EV chargers require considerable processing power to support the various protocols. Worse yet, these chargers can be connected to external systems in a variety of configurations including cloud-connected, mesh, direct-connect, SCADA “star”, or intermittently. To meet this challenge, Rhombus chargers utilize state-of-the-art embedded processors and software stacks in our chargers. We also use distributed database technologies in our chargers to enable them to share data with each other and with the cloud. This allows us to not only support today’s protocols and communications challenges, it enables us to add new software and applications to our existing software stacks as the demands on fleet chargers evolve.

Rhombus has built high-power inverters for renewable energy such as “behind the meter” grid energy storage systems for several years. We have applied that expertise to the design of our latest-generation bi-directional EV charging systems (which are designed from the start for the needs of fleet operators) and bi-directional smart inverter systems for microgrids. Rhombus expertise in energy management system (EMS) software is also embedded in our VectorStat EMS controller and software which is embedded in our EV charging systems and smart inverters. Rhombus also excels in the design and testing of high-power electrical equipment to meet the requirements of UL and other certification organizations. We have built hundreds of V2G-capable high-power, high-reliability chargers and bi-directional smart inverters for a variety of different sizes and classes of EVs. Find out how we can help you by contacting us at, or by reading our Vehicle to Grid Solution Brief.