A CAN bus charger is a lithium battery charger that communicates with the battery management system (BMS) over CAN bus (or RS485) instead of charging blind. The BMS tells the charger the pack's state; the charger follows, enabling safer, adaptive charging. JUXON Power, a professional lithium battery charger manufacturer based in Shenzhen, China, tunes CAN/RS485 profiles per customer BMS.
Why communicate with the BMS
Without communication, a charger applies a fixed CC/CV curve. With CAN bus, the BMS can cap current as cells approach full, report cell temperature, and trigger a controlled stop on fault — preventing overcharge and thermal events in unattended fleets.
| Mode | Signal | Benefit |
|---|---|---|
| Standalone | None | Simple, low cost |
| RS485 | Modbus/ASCII | Telemetry, polling |
| CAN bus | CAN 2.0B | Real-time BMS handshake |
Common in AGV and industrial
Automated guided vehicles, warehouse robots and opportunity-charging fleets rely on CAN bus to charge during short breaks without human oversight. See AGV/AMR chargers or discuss a custom CAN bus OEM charger with JUXON.
FAQ
CAN bus or RS485 — which should I choose?
CAN bus gives real-time, robust vehicle-network handshake and is standard in EVs/AGVs. RS485 (Modbus) is simpler for telemetry and PLC polling. Match the fleet's existing bus.
Can the charger read cell temperature?
Yes, when the BMS publishes temperature on the bus. The charger can then derate current to protect the pack — a key safety feature for unattended charging.
Do I need to share my BMS protocol?
Yes. Provide the CAN/RS485 frame definitions (IDs, scaling) so the charger firmware is matched. JUXON integrates customer protocols during OEM/ODM development.
Is CAN bus charging safe unattended?
When the BMS and charger handshake correctly, yes — the BMS can halt charging on over-voltage or over-temperature, which standalone chargers cannot do.