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JBD BMS JST plug type

dmq

New Member
Joined
Dec 15, 2021
Messages
6
Hi,

I want to use my BMS system JBD-SP04S020A UART with the dbus-serialbattery victron project (https://github.com/Louisvdw/dbus-serialbattery). At the moment a bluetooth module is connected with the UART port. I also got the JBD uart box and other possible USB TTL Serial adapters. Unfortunately the port on my bms is some strange type of JST 4 port female interface - please see the pictures. I can not find the type of plug / cable on the internet. Has some one an idea which type it is and where I can order one (JST PA, XA?). If I can not find the cable I will split the bluetooth cable and solder two cables (1 end for bluetooth, 1 end for USB TTL serial - just one connected at time not parallel) - another option would be to solder a "standard" JST 4 pin connector and replace the existing one on the board.

Here are some pictures - maybe some can help out? I am already mad because there are so many type of different (JST) plugs but nothing seems to match.

Thank you :)

dmq
 

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Thanks @MisterSandals - are you sure that this is the right plug? Look at the top of "my" picture - it looks like a "normal" JST 4 pin female but on the top is some kind of a protection. I also tried plugin in a 4-pin JST PH 2.0 - the ones which can be used as VE.Direct cables on Victron products - these do not fit in.
 
Thanks. I already cut off the cable of the bluetooth module. Now I have a Y-Connection, Bluetooth + USB-serial. In addtion I soldered an on/off switch for the bt-module (there is no access control possible, so it should not be always on in my opinion).

But thank you all again for your valuable recommendation :)
 
Thanks. I already cut off the cable of the bluetooth module. Now I have a Y-Connection, Bluetooth + USB-serial. In addtion I soldered an on/off switch for the bt-module (there is no access control possible, so it should not be always on in my opinion).

But thank you all again for your valuable recommendation :)
Do you have the link of these usb-serial? Thanks!
 
Do you have the link of these usb-serial? Thanks!


I ordered this one and it is already talked about here

 
I'm going down this rat hole as well. I have a bunch of JBD based BMS' (4S) that came with Bluetooth modules and the standard black box UART to USB adaptors like listed above from Overkill. I was going to simply attach jumper wires from the 4 pin UART plug on the BMS to an Arduino and then check things out. So I put a voltmeter on the Red and Black pins on the BMS UART port to see if it was 3.3v or 5.0v and holy cow the BMS pins are pumping out 12 volt power which would have fried the Arduino (glad I checked).

Also, the mentioned UART to USB box only has 3 wires feeding into the black box, which I assume is the TX line from the BMS. So as far as I can tell, the black box must level shift the voltage down for USB (fine) but I don't see how it can support BOTH read and write from the BMS, as it only has a three wire connection?

Can someone explain how a UART cable with VCC, Neg, and TX can receive input from the Overkill software? Is there a "real" UART to USB adaptor box that supports two way comms? What am I missing? Is the 3 wire set up using half duplex and sending and receiving on the same pin?
 
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Ok… With a little more investigation it’s now understandable…duh.

7AE6740E-68C9-4226-9DB0-647775A145D1.jpeg

The BMS board UART is VCC/TX/RX/GND at the pin port. The Bluetooth module uses the same wire pattern (and a rational color scheme of Red/White/White/Black) and draws power from the BMS. The UART to USB dongle uses the TX/RX/GND pins and a misleading wire scheme (Red/White/GND). So the UART to USB dongle draws power from the USB port and not the BMS port. I was relying on the wire colors and that was wrong on my parts. DERP
 
For anyone else who ends up here looking for answers, after a lot of searching and bit of trial and error, I've found that the plug type on the JBD BMS (for both the balance wires and the 4-pin UART/NTC connectors) is actually HY2.0.
Molex PicoBlade, JST-PA, JST PH 2.0 and the others mentioned in this thread are not a correct match.

I've bought a few from this seller, and they were identical to the ones supplied by JBD: https://www.aliexpress.com/item/1005005362950288.html
 
For anyone else who ends up here looking for answers, after a lot of searching and bit of trial and error, I've found that the plug type on the JBD BMS (for both the balance wires and the 4-pin UART/NTC connectors) is actually HY2.0.
Molex PicoBlade, JST-PA, JST PH 2.0 and the others mentioned in this thread are not a correct match.

I've bought a few from this seller, and they were identical to the ones supplied by JBD: https://www.aliexpress.com/item/1005005362950288.html

Thanks, this was helpful. Found some more to share:

Screenshot of page in case the link breaks.1687987594171.png
 
Ok… With a little more investigation it’s now understandable…duh.

View attachment 112990

The BMS board UART is VCC/TX/RX/GND at the pin port. The Bluetooth module uses the same wire pattern (and a rational color scheme of Red/White/White/Black) and draws power from the BMS. The UART to USB dongle uses the TX/RX/GND pins and a misleading wire scheme (Red/White/GND). So the UART to USB dongle draws power from the USB port and not the BMS port. I was relying on the wire colors and that was wrong on my parts. DERP
Thank you very much.
Hope the photos attached are helpful to others.
 

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Hello, I have seen that I need to modify commands in Nano to keep the JBD Bluetooth BMS connected or at least restart. I go to nano, but that is where I lose my way. Any assistance would be greatly appreciated.
 
Hi,

I want to use my BMS system JBD-SP04S020A UART with the dbus-serialbattery victron project (https://github.com/Louisvdw/dbus-serialbattery). At the moment a bluetooth module is connected with the UART port. I also got the JBD uart box and other possible USB TTL Serial adapters. Unfortunately the port on my bms is some strange type of JST 4 port female interface - please see the pictures. I can not find the type of plug / cable on the internet. Has some one an idea which type it is and where I can order one (JST PA, XA?). If I can not find the cable I will split the bluetooth cable and solder two cables (1 end for bluetooth, 1 end for USB TTL serial - just one connected at time not parallel) - another option would be to solder a "standard" JST 4 pin connector and replace the existing one on the board.

Here are some pictures - maybe some can help out? I am already mad because there are so many type of different (JST) plugs but nothing seems to match.

Thank you :)

dmq
It's the 2.0mm equivalent to the plug on most Bluetooth modules. The JBD store on AliExpress has the UART display with either 2.0mm or 2.43mm plug. For some reason the cell order is reversed. OverkillSolar Bluetooth adapters have the larger, BatteryHookup adapters have the smaller plug
 
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