esphome-pace-bms

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).

Supported devices

• Katbatt 6.4kWh LiFePO4 Stackable Battery, PACE BMS P16S200A (P16S200A-21473-1.03A310771030800025A), using RS485 protocol PACE_MODBUS
• PACE BMS P16S200A with firmware version 3 (P16S200A-21382-3.00T213822131800670H), using RS485 protocol PACE_MODBUS (#20)
• Gobel Power GP-SR1-LF280-RN150 51.2V 280Ah, PACE BMS S16A150 (JLD-BMS-S16A150), using RS485 protocol ModbusC1636
• Joyvoit Suns Energy Battery JVBW5KW, PACE BMS P16S100A (P16S100A-21468-1.00), using RS485 protocol PACE_MODBUS (#19)
• Orient Power Wall Mounted Battery 48V100AH, PACE BMS P16S100A-21236-2.01 (#31)
• SOK 100Ah 48V Server Rack Berry, PACE BMS P16S100A (P16S100A-1B470-4.07), using RS485 protocol PACE_MODBUS (#35)
• SOK 100Ah 48V Server Rack Berry, PACE BMS P16S100A (P16S100A-1B470-4.00), using RS485 protocol PACE_MODBUS (#38)
• MeritSun / i-finity LFP 200 - 48V (Modbus must be enabled by pbmstool.exe) (#29)
• Revov R100 51.2V 100Ah, PACE BMS P16S100A (P16S100A-12720-4.05G), using RS485 protocol SRNE (#39)

Untested devices

• Jakiper/BSLBATT 100Ah, PACE BMS P16S100A
• LIONTRON LiFePO4 LX48-100, 48V 100Ah
• Shenzen Delong 24V 100Ah, PACE BMS P16S200A-PC1547
• Hubble Lithium (AM2, AM4)
• Revov R9
• Greenrich U-P5000

Schematics

                  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.

RJ45 jack

Pin	Purpose	RS485-to-TTL pin	Color T-568B
1	B-	B-	Orange-White
2	A+	A+	Orange
3	GND	GND	Green-White
4	NC
5	NC
6	GND
7	A+
8	B-

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

BMS address

Module address	BMS Module ID	Dip1	Dip2	Dip3	Dip4
0x00	0	off	off	off	off
0x01	1	on	off	off	off
0x02	2	off	on	off	off
0x03	3	on	on	off	off
0x04	4	off	off	on	off
0x05	5	on	off	on	off
0x06	6	off	on	on	off
0x07	7	on	on	on	off
0x08	8	off	off	off	on
0x09	9	on	off	off	on
0x0A	10	off	on	off	on
0x0B	11	on	on	off	on
0x0C	12	off	off	on	on
0x0D	13	on	off	on	on
0x0E	14	off	on	on	on
0x0F	15	on	on	on	on

Requirements

• ESPHome 2024.6.0 or higher.
• Generic ESP32 or ESP8266 board

Installation

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

Example response all sensors enabled

TBD.

Known issues and limitations

None.

Protocol

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

The protocol is Modbus RTU via RS485.

Addr	Description	Len	R/W	Type	Unit
0	Current	2	R	int16	10mA
1	Voltage of pack	2	R	uint16	10mV
2	State of charge	2	R	uint8	%	0~100%
3	SOH	2	R	uint8	%	0~100%
4	Remain capacity	2	R	uint16	10mAH
5	Full capacity	2	R	uint16	10mAH
6	Design capacity	2	R	uint16	10mAH
7	Charging cycles count	2	R	uint16
9	Warning flag	2	R	uint16	Hex	See ^1
10	Protection flag	2	R	uint16	Hex	See ^2
11	Status/Fault flag	2	R	uint16	Hex	See ^3
12	Balance status	2	R	uint16	Hex
15	Cell voltage 1	2	R	uint16	mV
16	Cell voltage 2	2	R	uint16	mV
17	Cell voltage 3	2	R	uint16	mV
18	Cell voltage 4	2	R	uint16	mV
19	Cell voltage 5	2	R	uint16	mV
20	Cell voltage 6	2	R	uint16	mV
21	Cell voltage 7	2	R	uint16	mV
22	Cell voltage 8	2	R	uint16	mV
23	Cell voltage 9	2	R	uint16	mV
24	Cell voltage 10	2	R	uint16	mV
25	Cell voltage 11	2	R	uint16	mV
26	Cell voltage 12	2	R	uint16	mV
27	Cell voltage 13	2	R	uint16	mV
28	Cell voltage 14	2	R	uint16	mV
29	Cell voltage 15	2	R	uint16	mV
30	Cell voltage 16	2	R	uint16	mV
31	Battery temperature 1	2	R	int16	0.1 ℃
32	Battery temperature 2	2	R	int16	0.1 ℃
33	Battery temperature 3	2	R	int16	0.1 ℃
34	Battery temperature 4	2	R	int16	0.1 ℃
35	MOSFET temperature	2	R	int16	0.1 ℃	or invalid
36	Environment temperature	2	R	int16	0.1 ℃	or invalid
60	Pack OV alarm	2	RW	uint16	mV
61	Pack OV protection	2	RW	uint16	mV
62	Pack OV release protection	2	RW	uint16	mV
63	Pack OV protection delay time	2	RW	uint8	0.1S	1~255
64	Cell OV alarm	2	RW	uint16	mV
65	Cell OV protection	2	RW	uint16	mV
66	Cell OV release protection	2	RW	uint16	mV
67	Cell OV protection delay time	2	RW	uint8	0.1S	1~255
68	Pack UV alarm	2	RW	uint16	mV
69	Pack UV protection	2	RW	uint16	mV
70	Pack UV release protection	2	RW	uint16	mV
71	Pack UV protection delay time	2	RW	uint8	0.1S	1~255
72	Cell UV alarm	2	RW	uint16	mV
73	Cell UV protection	2	RW	uint16	mV
74	Cell UV release protection	2	RW	uint16	mV
75	Cell UV protection delay time	2	RW	uint8	0.1S	1~255
76	Charging OC alarm	2	RW	uint16	A
77	Charging OC protection	2	RW	uint16	A
78	Charging OC protection delay time	2	RW	uint8	0.1S	1~255
79	Discharging OC alarm	2	RW	uint16	A
80	Discharging OC protection	2	RW	uint16	A
81	Discharging OC protection delay time	2	RW	uint8	0.1S	1~255
82	Discharging OC-2 protection	2	RW	uint16	A
83	Discharging OC-2 protection delay time	2	RW	uint8	0.025S	1~255
84	Charging OT alarm	2	RW	int16	0.1 ℃
85	Charging OT protection	2	RW	int16	0.1 ℃
86	Charging OT release protection	2	RW	int16	0.1 ℃
87	Discharging OT alarm	2	RW	int16	0.1 ℃
88	Discharging OT protection	2	RW	int16	0.1 ℃
89	Discharging OT release	2	RW	int16	0.1 ℃
90	Charging UT alarm	2	RW	int16	0.1 ℃
91	Charging UT protection	2	RW	int16	0.1 ℃
92	Charging UT release protection	2	RW	int16	0.1 ℃
93	Discharging UT alarm	2	RW	int16	0.1 ℃
94	Discharging UT protection	2	RW	int16	0.1 ℃
95	Discharging UT release protection	2	RW	int16	0.1 ℃
96	MOSFET OT alarm	2	RW	int16	0.1 ℃	or invalid parameters in BMS-4820
97	MOSFET OT protection	2	RW	int16	0.1 ℃	or invalid parameters in BMS-4820
98	MOSFET OT release protection	2	RW	int16	0.1 ℃	or invalid parameters in BMS-4820
99	Environment OT alarm	2	RW	int16	0.1 ℃	or invalid parameters in BMS-4820
100	Environment OT protection	2	RW	int16	0.1 ℃	or invalid parameters in BMS-4820
101	Environment OT release protection	2	RW	int16	0.1 ℃	or invalid parameters in BMS-4820
102	Environment UT alarm	2	RW	int16	0.1 ℃	or invalid parameters in BMS-4820
103	Environment UT protection	2	RW	int16	0.1 ℃	or invalid parameters in BMS-4820
104	Environment UT release protection	2	RW	int16	0.1 ℃	or invalid parameters in BMS-4820
105	Balance start cell voltage	2	RW	uint16	mV
106	Balance start delta voltage	2	RW	uint16	mV
107	Pack full-charge voltage	2	RW	uint16	mV
108	Pack full-charge current	2	RW	uint16	mA
109	Cell sleep voltage	2	RW	uint16	mV
110	Cell sleep delay time	2	RW	uint16	min
111	Short circuit protect delay time	2	RW	uint8	25uS	Max 500uS
112	SOC alarm threshold	2	RW	uint8	%	0~100%
113	Charging OC-2 protection	2	RW	uint16	A
114	Charging OC-2 protection delay time	2	RW	uint8	0.025S	1~255
150	Version information	20	R	uint16	ASCII
160	Model SN	20	RW	uint16	ASCII	BMS Manufacturer
170	PACK SN	20	RW	uint16	ASCII	PACK Manufacturer

Known issues

None.

Debugging

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

References

• 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!)