When using Li‑ion batteries with a UPS, a reliable communication protocol is essential for safe charging, accurate SOC monitoring, and BMS‑UPS coordination. Below are the most widely used standards in the UPS & energy storage industry.

1. RS485 (Modbus RTU)

The most common protocol for industrial UPS and battery packs. Simple, stable, long‑distance transmission, and widely supported by BMS and UPS manufacturers.

2. CAN 2.0 / CANopen

High speed, strong anti‑interference, real‑time performance. Popular in high‑power UPS, energy storage systems, and industrial lithium batteries.

3. I2C

Typically used in small/built‑in battery modules for short‑distance, low‑speed communication between BMS and host.

4. SMBus (System Management Bus)

Common in smart lithium batteries, servers, and telecom backup power. Enables precise voltage, current, and SOC reporting.

5. RS232

Older but still used in some legacy UPS and lab equipment for short‑range, low‑speed data transmission.

Why protocols matter:

They ensure proper CC‑CV charging, real‑time SOC, temperature protection, balanced charging, active pre‑alarm, and safe shutdown — preventing overcharge, over‑discharge, swelling, or premature battery failure.

Daopulse UPS fully supports all mainstream lithium battery communication protocols for safe, stable, and long‑life lithium backup power.

Please feel free to contact us with any questions.

Whatsapp： +86 172 6699 4898

Email：hli@daopulse.com