JK BMS V19

[GeorgeSasDK]

No matter what I tried I can not make it work with JK Bms RS485.

All I get is error sending data.
2025-10-01 00:31:53.310 | INFO | Thread-14 | verter.BmsToInverter:335 | Sending to inverter NONE on /dev/ttyUSB0...
2025-10-01 00:31:53.343 | INFO | Thread-12 | verter.BmsToInverter:309 | Reading BMS #1 JK_RS485 on /dev/ttyACM0...
2025-10-01 00:31:53.343 | INFO | Thread-12 | toinverter.core.Port:111 | Opening /dev/ttyACM0 ...
2025-10-01 00:31:53.344 | INFO | Thread-12 | toinverter.core.Port:113 | Opening port /dev/ttyACM0 SUCCESSFUL
2025-10-01 00:31:53.345 | INFO | Thread-12 | toinverter.core.Port:111 | Opening /dev/ttyACM0 ...
2025-10-01 00:31:53.346 | INFO | Thread-12 | toinverter.core.Port:113 | Opening port /dev/ttyACM0 SUCCESSFUL
2025-10-01 00:31:53.348 | ERROR | Thread-12 | .JKBmsRS485Processor:199 | Error sending frame: Buffer (HEX): [0x4E, 0x57, 0x00, 0x13, 0x00, 0x00, 0x00, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x68, 0x00, 0x00, 0x01, 0x29]

2025-10-01 00:31:53.348 | INFO | Thread-12 | verter.BmsToInverter:361 |
BMS SOC V A CellMinV CellMaxV CellDiff

2025-10-01 00:31:53.350 | INFO | Thread-12 | verter.BmsToInverter:431 | BMS alarms:
NONE
2025-10-01 00:31:53.351 | INFO | Thread-12 | verter.BmsToInverter:309 | Reading BMS #2 JK_RS485 on /dev/ttyACM1...
2025-10-01 00:31:53.351 | INFO | Thread-12 | toinverter.core.Port:111 | Opening /dev/ttyACM1 ...
2025-10-01 00:31:53.352 | INFO | Thread-12 | toinverter.core.Port:113 | Opening port /dev/ttyACM1 SUCCESSFUL
2025-10-01 00:31:53.353 | INFO | Thread-12 | toinverter.core.Port:111 | Opening /dev/ttyACM1 ...
2025-10-01 00:31:53.353 | INFO | Thread-12 | toinverter.core.Port:113 | Opening port /dev/ttyACM1 SUCCESSFUL
2025-10-01 00:31:53.356 | ERROR | Thread-12 | .JKBmsRS485Processor:199 | Error sending frame: Buffer (HEX): [0x4E, 0x57, 0x00, 0x13, 0x00, 0x00, 0x00, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x68, 0x00, 0x00, 0x01, 0x29]

2025-10-01 00:31:53.356 | INFO | Thread-12 | verter.BmsToInverter:361 |
BMS SOC V A CellMinV CellMaxV CellDiff

2025-10-01 00:31:53.358 | INFO | Thread-12 | verter.BmsToInverter:431 | BMS alarms:
NONE
2025-10-01 00:31:53.359 | INFO | Thread-12 | verter.BmsToInverter:309 | Reading BMS #3 JK_RS485 on /dev/ttyACM2...
2025-10-01 00:31:53.359 | INFO | Thread-12 | toinverter.core.Port:111 | Opening /dev/ttyACM2 ...
2025-10-01 00:31:53.360 | INFO | Thread-12 | toinverter.core.Port:113 | Opening port /dev/ttyACM2 SUCCESSFUL
2025-10-01 00:31:53.360 | INFO | Thread-12 | toinverter.core.Port:111 | Opening /dev/ttyACM2 ...
2025-10-01 00:31:53.361 | INFO | Thread-12 | toinverter.core.Port:113 | Opening port /dev/ttyACM2 SUCCESSFUL
2025-10-01 00:31:53.363 | ERROR | Thread-12 | .JKBmsRS485Processor:199 | Error sending frame: Buffer (HEX): [0x4E, 0x57, 0x00, 0x13, 0x00, 0x00, 0x00, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x68, 0x00, 0x00, 0x01, 0x29]

2025-10-01 00:31:53.363 | INFO | Thread-12 | verter.BmsToInverter:361 |
BMS SOC V A CellMinV CellMaxV CellDiff

2025-10-01 00:31:53.365 | INFO | Thread-12 | verter.BmsToInverter:431 | BMS alarms:
NONE
2025-10-01 00:31:53.366 | INFO | Thread-12 | verter.BmsToInverter:309 | Reading BMS #4 JK_RS485 on /dev/ttyACM3...
2025-10-01 00:31:53.366 | INFO | Thread-12 | toinverter.core.Port:111 | Opening /dev/ttyACM3 ...
2025-10-01 00:31:53.367 | INFO | Thread-12 | toinverter.core.Port:113 | Opening port /dev/ttyACM3 SUCCESSFUL
2025-10-01 00:31:53.367 | INFO | Thread-12 | toinverter.core.Port:111 | Opening /dev/ttyACM3 ...
2025-10-01 00:31:53.368 | INFO | Thread-12 | toinverter.core.Port:113 | Opening port /dev/ttyACM3 SUCCESSFUL
2025-10-01 00:31:53.369 | ERROR | Thread-12 | .JKBmsRS485Processor:199 | Error sending frame: Buffer (HEX): [0x4E, 0x57, 0x00, 0x13, 0x00, 0x00, 0x00, 0x00, 0x06, 0x03, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x68, 0x00, 0x00, 0x01, 0x29]

2025-10-01 00:31:53.369 | INFO | Thread-12 | verter.BmsToInverter:361 |
BMS SOC V A CellMinV CellMaxV CellDiff

2025-10-01 00:31:53.369 | INFO | Thread-12 | verter.BmsToInverter:431 | BMS alarms:
NONE
^C2025-10-01 00:31:54.259 | WARN | Thread-1 | verter.BmsToInverter:461 | Starting shutdown.
2025-10-01 00:31:54.259 | INFO | Thread-1 | verter.BmsToInverter:466 | Shutting down BMS and inverter threads...OK
Weld SE container 2fbda114-1f08-481b-9e9c-86be17217008 shut down by shutdown hook
2025-10-01 00:31:54.263 | INFO | Thread-1 | verter.BmsToInverter:474 | Shutting down MQTT producer threads...OK
2025-10-01 00:31:54.381 | INFO | Thread-1 | tt.MQTTBrokerService:110 | Shutting down MQTT broker on 'tcp://127.0.0.1:61616'...OK
2025-10-01 00:31:54.381 | INFO | Thread-1 | verter.BmsToInverter:483 | Shutting down MQTT broker threads...OK
2025-10-01 00:31:54.384 | INFO | Thread-1 | er.AbstractConnector:383 | Stopped ServerConnector@5e0ec41f{HTTP/1.1, (http/1.1)}{0.0.0.0:8080}
2025-10-01 00:31:54.386 | INFO | Thread-1 | er.AbstractConnector:383 | Stopped ServerConnector@76332405{SSL, (ssl, http/1.1)}{0.0.0.0:8443}
2025-10-01 00:31:54.386 | INFO | Thread-1 | .session.HouseKeeper:149 | node0 Stopped scavenging
2025-10-01 00:31:54.389 | INFO | Thread-1 | verter.BmsToInverter:492 | Shutting down webserver threads...OK
2025-10-01 00:31:54.390 | INFO | Thread-1 | verter.BmsToInverter:500 | Shutting down ports...OK

Runing on UBUNTU and Waveshare USB to RS485 with 4 ports.
/dev/ttyACM0
/dev/ttyACM1
/dev/ttyACM2
/dev/ttyACM3

Tested on a Windows machine with BMS Monitor and I can connect with no problem.

[kommando828]

The V19 is a return to messed up comms, lets face it there were 41 releases for the V15 before they sort of got it nearly right. Not got a V19 yet but one is on route and I expect issues. Luckily I have a spare V15 if I cannot get it to behave. They seem to have changed now the board connects in parallel and if you initially set it up in a particular way you lose the ability to parallel connect.

https://diysolarforum.com/threads/jk-bms-v19-broken-parallel-comms.110148/

Worth a watch

https://youtu.be/XzW2QxAmssI

[GeorgeSasDK]

Well , works fine from the PC on all 3 RS485 ports using BMS monitor but in bms-to-inverter can't make it work for the love of my life ... been trying now all kind of stuff ... nothing works.

[kommando828]

My delivery date is late Nov so until then I cannot try to see if anything works.

…

On Wed, 1 Oct 2025 at 09:29, GeorgeSas ***@***.***> wrote: Well , works fine from the PC on all 3 RS485 ports using BMS monitor but in bms-to-inverter can't make it work for the love of my life ... been trying now all kind of stuff ... nothing works. — Reply to this email directly, view it on GitHub <#161 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AHVWRWC3X3BYAI7OF5JIXU33VOGGRAVCNFSM6AAAAACH6IN2H6VHI2DSMVQWIX3LMV43URDJONRXK43TNFXW4Q3PNVWWK3TUHMYTINJWGA3DINY> . You are receiving this because you commented.Message ID: ***@***.*** .com>

[GeorgeSasDK]

I will try to change the RS485 protocol in the BMS to one of the others like they show in video .. LCD or something else.
JK documentation is super annoying ...

[GeorgeSasDK]

Ok , this software seems to be pretty buggy ....
I can't get it to work on Ubuntu with Waveshare RS485 and JK V19 but I can't get it to read BMS data either from Pylontech on RS485.
So I think I must give up all hope on this and look for alternatives.
Pylontech which is quite old and still not work on RS485 ... disappointing :(

[ai-republic]

@GeorgeSasDK can you please configure the log level to debug. I can't see from the above log why its failing to send the RS485 frame. The send-frame looks good, but possibly your wiring to your RS485 hat is wrong.

[GeorgeSasDK]

Ok, so my config changed a bit as I need to use RS485 , more information present in RS485 protocol than CAN....but still NO RS485 communication with batteries. Attached LOG with debug level.
My RS485 is on /dev/ttySC0 and if I test with simple python script it works fine.

Attached also Python script for /dev/ttySC0
PylonRS485_Serial0.py

BMS-to-Inverter.log

[GeorgeSasDK]

I've been monitoring on one console the ttySC0 ... and your script does not seem to send ANYTHING on this port ... just listens ?
On RS485 the Pylontech does not broadcasts , it needs to send requests to the battery to receive an answer.
Pylon-RS485-protocol-V3.5.pdf

Pylontech RS485 Battery Monitor
Port: /dev/ttySC0 (115200 baud)

Sending request for battery analog data (0x42)...
TX: 7E3230303234363432453030323032464433330D
RX: 7E3230303234363030463037413131303230463044324330443233304432443044333130443246304432363044324630443331304432393044324630443244304432463044324530443330304432443035304238453042383830423838304238363042383830303030433541314646464630344646464630303032303131423438303132313130453241450D

======================================================================
PYLONTECH BATTERY DATA (RS485 - /dev/ttySC0)

Module Status:
Voltage: 50.593 V
Current: 0.000 A
Power: 0.00 W (Idle)

Capacity:
SOC: 98.0%
Remaining: 72.52 Ah
Total: 74.00 Ah

Cycle Count: 2

Cell Voltages (15 cells):
Cell 01: 3.372 V
Cell 02: 3.363 V
Cell 03: 3.373 V
Cell 04: 3.377 V
Cell 05: 3.375 V
Cell 06: 3.366 V
Cell 07: 3.375 V
Cell 08: 3.377 V
Cell 09: 3.369 V
Cell 10: 3.375 V
Cell 11: 3.373 V
Cell 12: 3.375 V
Cell 13: 3.374 V
Cell 14: 3.376 V
Cell 15: 3.373 V

Cell Summary:
Min: 3.363 V
Max: 3.377 V
Imbalance: 0.014 V

Temperatures:
BMS : 22.7°C
Cells 1-4 : 22.1°C
Cells 5-8 : 22.1°C
Cells 9-12 : 21.9°C
Cells 13-15 : 22.1°C

[ai-republic]

I think there's something wrong with your configuration of the BMSes and their IDs. The application requests the data actively from the BMS.
Can you please your config and when you test then please select debug log level and inverter NONE and no other extensions like webserver, etc.

[GeorgeSasDK]

Not sure what and how you actively request data on RS485 from Pylontech because I can't see anything on RS485.
I am no programmer but looking at the log (set to debug) , I can't see any TX data on RS485.

BMS-to-Inverter.log
config.properties.txt

[ai-republic]

I saw that you set the BMS ID to 2. I checked the spec again and saw that the group id was lacking in my code.
I changed the BMS addressing now (needs to be appended to the group ID 0x10 + BMS ID) and added some more debug logging.
Could you do a Clean install and post the log here please?

[GeorgeSasDK]

Tested again with Both Pylontech and JK Inverter BMS (v19), the RS485 protocol does not work.
Attached LOG from Pylontech config and JK Config. With JK I tested both RS485 and Modbus... no worky :(
BMS-to-InverterJKBMS.log
BMS-to-Inverter-pylonRS.log
I attach also my Python script that works on RS485. This when I was connected only to 1 battery and seems only to pull data from master.

WorkingPylonDecoder.py

[GeorgeSasDK]

If you need I can give you access to a Raspberry PI with 2 RS485 ports connected to both Pylontech RS485 and JK RS485.

[GeorgeSasDK]

Attached an RS485 sniffed log when Solar Assistant is connecting RS485
Note : In the log are both the requests from Solar Assistant and the reply from Pylontech.
rs485_capture.log

[GeorgeSasDK]

And a script that will read all batteries via RS485.
Pylon_Complete_Monitor.py

[ai-republic]

I compared the logs and the python scripts for the Pylon RS485 communication and they actually do the same as mine.
Now your Pylon RS485 log still states that:

This message comes from the serial communication library and it works fine for other users.
Which means there is still something not correct with the PI configuration or the port is not started and configured properly (baudrate, etc.) prior to starting the application.