Bi-Directional DC-DC Converter for Commercial Vehicles

"We need a Bi-Directional DC-DC Converter for Commercial Vehicle Power Management System"

Power Type

DC-DC Converter

Product

BCH Series

Brand

Industry

E-Mobility

A leading manufacturer of hybrid commercial vehicles required a high-efficiency, automotive-grade DC-DC converter to manage power transfer between 12V and 48V battery systems. The application demanded precise control, rugged environmental protection, and compliance with stringent automotive standards to ensure reliable operation in harsh on-road conditions.

The customer needed a 3000W solution capable of bi-directional operation to both charge the low-voltage battery during normal running and supplement the high-voltage system during peak demand.

Key requirements included:

Operation across a wide input range of 12–60Vdc
Compact footprint to fit existing vehicle architecture (under 265mm in length)
IP69K ingress protection for operation in high-pressure wash-down environments
Compliance with E-Mark automotive approval
Integration with the vehicle’s CAN bus for control and monitoring
High efficiency to minimise thermal management challenges

Relec recommended the BCH Series 3,000W bi-directional DC-DC converter for commercial vehicles from Calex. For this application, the 60S12.215BCH model was specified, offering 60V to 12V operation in both buck and boost modes.

Key technical advantages included:

Up to 98.4% efficiency, reducing heat load and improving system performance
Fully programmable current control via CAN 2.0b
Constant voltage and constant current modes for optimised charging profiles
Rugged aluminium housing rated to IP69K for complete dust and water ingress protection
Integrated temperature sensing and latching fault protection for overvoltage, overcurrent, and over-temperature events

Our expert team worked closely with the customer to configure the CAN settings, define custom charging profiles, and advise on thermal integration to ensure reliable full-load operation at ambient temperatures from -40°C to +85°C.

The BCH Series unit delivered stable, high-efficiency power transfer between the two battery systems, enabling the vehicle to handle transient load spikes without compromising 12V system reliability. The rugged design ensured fault-free operation even in extreme weather and after repeated pressure washing.

“The converter integrated seamlessly with our control system and has proven exceptionally robust under real-world conditions.”

Commercial Vehicle Manufacturer

Project Engineer

By combining robust automotive-grade design with advanced control features, Relec provided a solution that not only met the customer’s requirements but also offered headroom for future system upgrades in their hybrid vehicle platform.