CAN Communication and BMS Integration Checklist for OBC
CAN communication and BMS integration checklist for OBCs: messages, baud rate, wake-up, diagnostics, and fault handling for EV OEM engineers. Read more.
Related reading: How to Choose an On-Board Charger (OBC) for Commercial EVs · What Is a Bidirectional OBC? V2L, V2V, and V2G Explained · OBC RFQ Checklist: What EV Manufacturers Should Provide Before Requesting a Quotation
FAQ
What is the difference between CAN 2.0 and CAN FD?
CAN FD (Flexible Data-rate) can carry larger payloads and higher data rates than classic CAN 2.0. A CAN FD controller can usually talk to a CAN 2.0 node, but not at FD rates. Confirm which version your VCU and OBC both support, and at what baud rate.
Who should control charge termination — the OBC or the BMS?
In most designs, the BMS is the authority, because it knows cell voltage, temperature, and SoC. The OBC follows the BMS request and provides its own protection as a backup. Confirm this division in writing for your system.
What happens if CAN is lost during charging?
That must be defined in the specification. Common safe behaviours are to stop charging, ramp down to a safe current, or hold the last request for a short timeout and then stop. Confirm the behaviour for the specific model with the supplier.
Do I need UDS diagnostics for an OBC?
Not always, but UDS makes service and fault diagnosis much easier, especially in a fleet. If UDS is listed for the dual-input unit, ask whether it is available on your model and which services are supported.
What documents should I ask for?
Ask for the CAN database file (DBC), the CAN protocol document, the fault-code list, the charge-control specification, the wake-up / sleep specification, and the UDS diagnostic specification, for the specific model. Confirm lead time for any custom CAN configuration directly with the engineering team.
Related Echelon Products
See the full range on the products page.
Next Step
Send the Echelon engineering team your VCU CAN version and baud rate, your BMS charge profile, and your wake-up / sleep requirements, and request the DBC file, protocol document, and fault-code list for the matching OBC. Review them against the checklists above before you freeze the hardware.
To start, share your vehicle and battery requirements through our contact page, and see how a custom programme is scoped on our OEM/ODM page. Before requesting a quotation, the OBC RFQ checklist lists the inputs that let Echelon quote accurately in one pass.
About Echelon Charger
Echelon Energy Technology specializes in onboard chargers, DC/DC converters, and integrated EV power solutions for commercial and specialty electric vehicles.
For technical discussions, product selection, or OEM/ODM cooperation:
Email: nancy@tici-energy.com
WhatsApp: +86 18114665311