CAN Bus

What is CAN bus

CAN (Controller Area Network) bus is a serial communication protocol used between Battery Management Systems (BMS) and solar inverters (and other devices) to exchange operational data. Originally developed by Bosch in the 1980s for automotive applications, CAN has become the standard communication protocol for modern lithium-ion battery storage in solar applications.

CAN bus uses differential signalling on a twisted pair (CAN_H and CAN_L) with 120-ohm termination. Standard CAN operates at up to 1 Mbit/s, with CAN FD (Flexible Data-Rate) supporting up to 8 Mbit/s. The protocol is robust against electrical noise and supports multi-device networks. See Battery Management System (BMS) in Hybrid Solar Inverters, Decoded for how CAN bus compares with RS485 Modbus in real BMS-inverter pairings.

For solar hybrid inverter-battery integration, CAN bus enables continuous data exchange:

• Battery: reports SOC, voltage, current, temperature, SOH, alarms
• Inverter: receives data, sends control commands, requests data

For Indian solar, CAN bus is the dominant communication protocol for hybrid inverter battery packs. Compatibility between specific inverter brands and battery brands depends on protocol matching, leading to inverter-battery compatibility lists — a check covered in How to Choose a Hybrid Solar Inverter, 5-Step Decision Guide.

Why CAN bus matters

Hybrid inverter integration. Standard protocol enables BMS-inverter communication.

Battery monitoring. Real-time data for EMS and apps.

Charge control. Inverter respects BMS-reported charge limits.

Safety. Fault and alarm communication.

Pack expansion. Multiple battery modules communicate.

CAN bus structure

Technical deep dive

CAN message format

Typical BMS-inverter messages

Compatibility lists

Major inverter brands publish compatibility lists for battery brands:

Cable and topology

Real-world applications

Hybrid inverter to battery communication.

Multi-module battery expansion, coordinated through CAN-reported cell balancing status across packs.

EV BMS to vehicle control.

Industrial battery storage.

Backup power systems.

Best practices

Verify CAN protocol compatibility before inverter and battery procurement.

Update firmware to match between BMS and inverter.

Document protocol version in design.

Indian market context

CAN bus is standard for Indian hybrid solar storage.

Major Indian LFP brands (Pylon Tech, BYD, Goodwe Storage, Sungrow, Solax) support CAN.

Inverter compatibility lists published by manufacturers.

Domestic BMS developers (Inverted Energy, Battrixx) implement standard CAN protocols.

Standards and certifications

Key takeaways

CAN bus is the standard communication protocol between BMS and solar inverter in modern lithium-ion storage. Enables real-time data exchange of SOC, voltage, current, temperature and control commands. Indian hybrid inverter-battery integration relies on CAN compatibility lists. Verify protocol compatibility before procurement. Standard cabling, termination and protocol matching ensure reliable communication.

Further reading

For how CAN Bus plays out in real projects, these guides go deeper:

• BMS in Hybrid Solar Inverters, Decoded
• Inverter Battery Connection Diagram and Sizing Guide for Hybrid Solar
• Solar Inverter Integration, 7-Phase EPC Setup Guide
• Solar Inverter vs UPS, What’s the Real Difference?

Sources

• ISO 11898, CAN standard.
• Manufacturer documentation from Pylon Tech, BYD, Goodwe.
• Inverter compatibility lists from Sungrow, Solis, Goodwe, Solax, Deye.
• IEEE Power Electronics Society publications.
• NREL BMS Communication Studies.
• BloombergNEF Battery Storage Outlook.
• IEA Energy Storage Outlook 2024.
• Automotive CAN bus literature.
• Bosch CAN Specification.