ESPHome configuration to monitor and control a PACE Battery Management System (PACE-BMS) via RS485 (Modbus)

This project implements the PACE_MODBUS protocol. Please use the RS485 port next to the CAN bus port and enable the protocol using the PbmsTools.exe (System Config -> Inverter protocol -> RS485 Protocol).

• Katbatt 6.4kWh LiFePO4 Stackable Battery, PACE BMS P16S200A (P16S200A-21473-1.03A310771030800025A), using RS485 protocol PACE_MODBUS
• Gobel Power GP-SR1-LF280-RN150 51.2V 280Ah, PACE BMS S16A150 (JLD-BMS-S16A150), using RS485 protocol ModbusC1636

• Gobel Power GP-SR1-RN150 51.2V 280Ah, PACE BMS P16S200A
• Jakiper/SOK/BSLBATT/ 100Ah, PACE BMS P16S100A
• LIONTRON LiFePO4 LX48-100, 48V 100Ah
• Shenzen Delong 24V 100Ah, PACE BMS P16S200A-PC1547
• PACE BMS P16S100A-PC1447
• Hubble Lithium (AM2, AM4)
• Revov R100
• Revov R9
• Greenrich U-P5000

                  RS485                      UART
┌────────────┐              ┌──────────┐                ┌─────────┐
│            │              │          │<----- RX ----->│         │
│    PACE    │<-----B- ---->│  RS485   │<----- TX ----->│ ESP32/  │
│    BMS     │<---- A+ ---->│  to TTL  │<----- GND ---->│ ESP8266 │
│            │<--- GND ---->│  module  │<----- 3.3V --->│         │<-- VCC
│            │              │          │                │         │<-- GND
└────────────┘              └──────────┘                └─────────┘

Please make sure to power the RS485 module with 3.3V because it affects the TTL (transistor-transistor logic) voltage between RS485 module and ESP.

Please be aware of the different RJ45 pinout colors (T-568A vs. T-568B).

• ESPHome 2022.4.0 or higher.
• Generic ESP32 or ESP8266 board

Use the esp32-example.yaml as proof of concept:

# Install esphome
pip3 install esphome

# Clone this project
git clone https://github.com/syssi/esphome-pace-bms.git
cd esphome-pace-bms

# Create a secrets.yaml containing some setup specific secrets
cat > secrets.yaml <<EOF
wifi_ssid: MY_WIFI_SSID
wifi_password: MY_WIFI_PASSWORD

mqtt_host: MY_MQTT_HOST
mqtt_username: MY_MQTT_USERNAME
mqtt_password: MY_MQTT_PASSWORD
EOF

# Validate the configuration, create a binary, upload it, and start logs
# If you use a esp8266 run the esp8266-examle.yaml
esphome run esp32-example.yaml

TBD.

None.

See docs/PACE-BMS-Modbus-Protocol-for-RS485-V1.3-20170627.pdf.

The protocol is Modbus RTU via RS485.

None.

If this example doesn't work out of the box for your device please update your configuration to enable the debug output of the UART component and increase the log level to the see outgoing and incoming serial traffic:

logger:
  level: DEBUG
  # Don't write log messages to UART0 (GPIO1/GPIO3) if the BMS is connected to GPIO1/GPIO3
  baud_rate: 0

uart:
  - id: uart_0
    baud_rate: 9600
    tx_pin: ${tx_pin}
    rx_pin: ${rx_pin}
    debug:
      direction: BOTH
      dummy_receiver: false

• https://www.akkudoktor.net/forum/bms-batterie-management-monitoring-system/pace-bms-informationssammlung/
• https://docs.google.com/document/d/1JqBizjyOrAge02pO-S6asDoAJgEdHV0Ujbs3BCCvXLo/edit
• https://powerforum.co.za/topic/13982-bms-pace-addon-for-home-assistant-as-used-by-hubbles-am-2-and-am-4/ (different protocol!)
• https://github.com/fancyui/Gobel-Power-RN-BMS-RS485-ModBus (different protocol!)
• https://github.com/Tertiush/bmspace (different protocol!)