Older style JK-BMS daisy chain

[maxx8888]

Hi,
I was searching a lot on the Internet today and read through a lot of discussions. However i didn't come to a final conclusion.
I'm using JKBMS the older Black Versions (non Inverter), mostly called B2A20S20P. Firmware Version 11.XW S11.25.
With original RS485 Adapter from JK plugged into GPS Port of the BMS and connected to Raspi via 3 original Victron RS485 Cables.
Serial Battery Version: 1.4.20240928
This Setup was now running 2 Years fine.

Since i'm planning to extend with further Batteries, i wanted to try if i can daisy chain them by setting up DeviceIDs to 1,2,3 via Bluetooth App and connecting all of them in parrallel and to 1 RS485 Adapter.

Changed config from Serial Battery to:
MODBUS_ADDRESSES = 0x01, 0x02, 0x03
BMS_TYPE = Jkbms (also tested Jkbms_pb)

However, after restarting Serial Battery with this setup i get a lot of "No Reply" and a lot of Checksum Errors in the Logs.
Should this setup work at all or is there no support for this BMS Type?
Could it be that all of them are answering at the same time?
Do i need to get a Termination Resistor?

Log (sorry no timestamp):
INFO:SerialBattery:Testing Jkbms at address "\x01"
@4000000067b3bc1b211d93c4 ERROR:SerialBattery:CRC checksum mismatch: Expected 0x0000, Got 0x004f
@4000000067b3bc1c035ddac4 INFO:SerialBattery:-- Testing BMS: 3 of 3 rounds
@4000000067b3bc1c0364e774 INFO:SerialBattery:Testing Jkbms at address "\x01"
@4000000067b3bc1c0acc80e4 ERROR:SerialBattery:CRC checksum mismatch: Expected 0xc0ff, Got 0x20af
@4000000067b3bc1c2896c134 WARNING:SerialBattery:No battery connection at /dev/ttyUSB1 and this Modbus address 0x01
@4000000067b3bc1c289b6c84 INFO:SerialBattery:-- Testing BMS: 1 of 3 rounds
@4000000067b3bc1c28a16f94 INFO:SerialBattery:Testing Jkbms at address "\x02"
@4000000067b3bc1c29afedac ERROR:SerialBattery:CRC checksum mismatch: Expected 0x0400, Got 0x0118
@4000000067b3bc1d0bf2d874 INFO:SerialBattery:-- Testing BMS: 2 of 3 rounds
@4000000067b3bc1d0bf875f4 INFO:SerialBattery:Testing Jkbms at address "\x02"
@4000000067b3bc1d0d029eac ERROR:SerialBattery:CRC checksum mismatch: Expected 0x0600, Got 0x008b
@4000000067b3bc1d2adf9024 INFO:SerialBattery:-- Testing BMS: 3 of 3 rounds
@4000000067b3bc1d2ae51a1c INFO:SerialBattery:Testing Jkbms at address "\x02"
@4000000067b3bc2d27f13e1c ERROR:SerialBattery:>>> ERROR: No reply - returning [len:245/518]
@4000000067b3bc2e0a819534 WARNING:SerialBattery:No battery connection at /dev/ttyUSB1 and this Modbus address 0x02
@4000000067b3bc2e0a8dca34 INFO:SerialBattery:-- Testing BMS: 1 of 3 rounds
@4000000067b3bc2e0a8dddbc INFO:SerialBattery:Testing Jkbms at address "\x03"
@4000000067b3bc3e070979bc ERROR:SerialBattery:>>> ERROR: No reply - returning [len:206/267]
@4000000067b3bc3e2508f30c INFO:SerialBattery:-- Testing BMS: 2 of 3 rounds
@4000000067b3bc3e250ec73c INFO:SerialBattery:Testing Jkbms at address "\x03"
@4000000067b3bc3e25ff709c ERROR:SerialBattery:CRC checksum mismatch: Expected 0x0400, Got 0x011a
@4000000067b3bc3f0842efd4 INFO:SerialBattery:-- Testing BMS: 3 of 3 rounds
@4000000067b3bc3f08493164 INFO:SerialBattery:Testing Jkbms at address "\x03"

[stefan-12]

Hi,
i suppose you had the same problem as i had with a victron RS485 Adapter. Have a look on this thread:
#176
DaisyChaining needs more professional RS485-USB Adapters.

• in my setup i had to use "BMS_TYPE = Jkbms_pb" other settings did not work.
• Modbus Adresse 0 is forbidden. this ist used for can-Bus daisyChain
• You have to configure communication in your JK BMS. UART2 Protocoll has to be set to 1 = JK BMS RS485 Modbus V1.0
• you have to connect the correct cables of the JK BMS. I used the Path cable connector at the Front RS485-2.
• The pins are mirrord. The pin on the left (1) and on the right (8) are RS485 Channel B
• The second pin on the left (2) and on second the right (7) are RS485 Channel A
• Pint 3 and 6 are GND
• Maybe you FS485 Adapter is bad or to cheap. have a look on the Thread 176: