Victron VenusOS driver for serial connected BMS - LLT/JBD / Daly Smart / ANT / JKBMS / Heltec / Renogy

jamiegreen

New Member
Joined
Nov 8, 2021
Messages
67
Yep, very small. I ordered a set of the cables I mentioned, and the USB-serial converter. Let's see.

I couldn't find an 'official JK' thing with a female 3-pin slot, so that puzzled me. And you still need the USB converter after that.

When the stuff arrives, I'll let you know, current expectation is that this will be somewhere in December ;)

The official JK converter does have the connector on the one end, but only bare cable on the other end, so yes this would then need to be terminated into a rs485 to USB converter, which sounds like one converter too many for my liking. I've ordered that one I linked, if worst comes to worst the soldering iron will be coming out.
 

Martijn

Solar Enthusiast
Joined
May 6, 2021
Messages
141
The official JK converter does have the connector on the one end, but only bare cable on the other end, so yes this would then need to be terminated into a rs485 to USB converter, which sounds like one converter too many for my liking. I've ordered that one I linked, if worst comes to worst the soldering iron will be coming out.
"does have the connector on the one end"

Yes, but it looks like a 4 pin connector. Perhaps your BMS has the 4-pin GPS/RS485 combined port, mine has a 3-pin RS485 port.
 

jamiegreen

New Member
Joined
Nov 8, 2021
Messages
67
"does have the connector on the one end"

Yes, but it looks like a 4 pin connector. Perhaps your BMS has the 4-pin GPS/RS485 combined port, mine has a 3-pin RS485 port.
Judging by the labelling on the converter box I'd assume it's the 3 pin connector, there's no real good images of it though.
Screenshot_2021-11-26-08-21-49-770_com.alibaba.aliexpresshd.jpg
 

Martijn

Solar Enthusiast
Joined
May 6, 2021
Messages
141
H121f41a82ab94b1287a9c1ebf7b01d66Q.jpg

3 wires on the outgoing side, 4 on the connector side? Either way, the GPS connector on my BMS is 4-pin, so given that there are BMSses with combined ports, it could have changed somewhere along the line.

 

jamiegreen

New Member
Joined
Nov 8, 2021
Messages
67
H121f41a82ab94b1287a9c1ebf7b01d66Q.jpg

3 wires on the outgoing side, 4 on the connector side? Either way, the GPS connector on my BMS is 4-pin, so given that there are BMSses with combined ports, it could have changed somewhere along the line.

Ah you might be right there, perhaps all official converters have 4 pin connectors. But yes my BMS is the same as yours with a 3 pin RS485, 4 pin GPS and.. something pin unknown Chinese writing (maybe a factory testing plug)
 

jamiegreen

New Member
Joined
Nov 8, 2021
Messages
67
I talked to JK BMS and got something of an answer. The official converter connects to the GPS port with its 4 pin connector, this port also (I think) shares the same output as the rs485 port.
On second thoughts.. the support team mentioned a "typographical error" and I wonder if they were referring to the fact that one port is labelled rs485 but actually isn't, they weren't very clear. Either way the GPS port is what JK use for communication.
As for what the white port connector is called, they just said "sorry, we only recommend using official converter".
 

Attachments

  • Capture.PNG
    Capture.PNG
    22.1 KB · Views: 17
  • H736e96b15ca848c9a9a42c06e6d702c7o.jpg
    H736e96b15ca848c9a9a42c06e6d702c7o.jpg
    808.5 KB · Views: 17
Last edited:

tortfeaser

New Member
Joined
Mar 8, 2021
Messages
2
This fantasic @lewisvdw! Thanks.

Based on what I've seen here, I've ordered 350Ah of LiFePO4 at 12v (4s2p) and a JBD 200A smart BMS. I already have (on my boat) a RPi 3A+ running Venus OS, a Victron smart MPPT solar charger (VE.Direct to the Venus), BMV712 (VE.Direct), Multiplus 12/800/35 inverter/charger (VE.Bus), and a BatteryProtect device to disconnect house loads on low battery voltage.

Can anyone see holes in my plan?

I will add the BMS, a RS485 serial USB adaptor, a Victron Orion 12/12-30A DC-DC charger (to avoid killing the alternator) and Cyrix-Li-Ct battery combiner (to preferentially charge the AGM starter battery).

I plan to connect the Venus relay output to both the Orion and the Cyrix to disable charging for cell overvoltage.

I'm expecting that the driver (from the BMS) will tell the Venus whether the cell over- or cell under-voltage alarms is triggered, the SOC and battery voltage and current info.

I'm expecting using those data, the Venus will:
(a) tell the multiplus and MPPT chargers what voltage and current to charge at (via VE.Bus and VE.Direct), and
(b) if an cell over-voltage error is triggered by the driver (from the BMS), that charging:
(i) will be disabled in the multiplus and MPPT chargers by VE.Bus and VE.Direct and
(ii) disabled for the Orion DC-DC charger and Cyrix battery combiner by the relay.

I'm expecting the driver to tell the multiplus to disable inverting on the cell undervoltage alarm.

Does this all sound right?

Thanks again Louis!

Marc
 

Louisvdw

Solar Enthusiast
Joined
Dec 18, 2020
Messages
93
I'm expecting using those data, the Venus will:
(a) tell the multiplus and MPPT chargers what voltage and current to charge at (via VE.Bus and VE.Direct), and
(b) if an cell over-voltage error is triggered by the driver (from the BMS), that charging:
(i) will be disabled in the multiplus and MPPT chargers by VE.Bus and VE.Direct and
(ii) disabled for the Orion DC-DC charger and Cyrix battery combiner by the relay.
a) yes. When the battery is full the Venus will lower the MPPTs to only produce what is used by the rest of the system
b) yes. The alarms will trigger the Venus's routines. I'm not sure about the Orion with the relay, but if Venus can to it, then the driver will enable to BMS feedback so that Venus can does it's magic.

The rest all looks like it will work. Just make sure the BMS is set as the Battery Monitor in the Venus settings (should if on auto) and you will be fine.
 

jamiegreen

New Member
Joined
Nov 8, 2021
Messages
67
I have now purchased a TTL to USB converter, and just so happens to find the exact connector needed inside a CCTV camera that got damaged in a storm..
Will give it a try.. I'd like to say soon but probably after Christmas!
IMG_20211205_212901.jpg
 

tortfeaser

New Member
Joined
Mar 8, 2021
Messages
2
a) yes. When the battery is full the Venus will lower the MPPTs to only produce what is used by the rest of the system
b) yes. The alarms will trigger the Venus's routines. I'm not sure about the Orion with the relay, but if Venus can to it, then the driver will enable to BMS feedback so that Venus can does it's magic.

The rest all looks like it will work. Just make sure the BMS is set as the Battery Monitor in the Venus settings (should if on auto) and you will be fine.
Fantastic. Thanks Louis.

So the only real unknown is the relay function with Venus, and picking the right assistant. But even if I can't make it work natively with Venus, the Venus large package that includes Node Red would be able to manage.

Install and testing next. Wonder if I could come up with some utility to mock BMS alarm outputs via RS485 or RS232?
 

Louisvdw

Solar Enthusiast
Joined
Dec 18, 2020
Messages
93
Wonder if I could come up with some utility to mock BMS alarm outputs via RS485 or RS232?
If you are comfortable with SSH and Linux, then just log in to your GX and run the dbus-spy that is part of Victron's toolset included in the VenusOS.
Browse to /Alarms/ and then you can trigger some alarm like LowVoltage. This is the same place the driver raise alarms so it will remove them again so you might have to disconnect the BMS
0=OK; 1=Warning; 2=Alarm
 

stewyl

New Member
Joined
Feb 10, 2021
Messages
4
Hey all i hope you can help. Seeing people have been talking about the serial connections above.

Ive got a Overkill-Solar BMS (JBD) which has the BT module with it for configuring it etc. Ive also got a spare VE-Direct Serial cable can i use this with the BMS to connect to Venus OS? If so does anyone know the pinout? If not what usb to serial cable do i need?

I have had this working with a daly smart BMS in the past but there was some kind of ground issue with this and it killed my PI using the daly usb serial adaptor.
 

Louisvdw

Solar Enthusiast
Joined
Dec 18, 2020
Messages
93
@stewyl you only connect the ground and 2 data wires RX and TX and keep the power wire disconnected. Except if you have a seperate UART port, this will go in the socket where your bluetooth module is currently conected.
 

stewyl

New Member
Joined
Feb 10, 2021
Messages
4
@stewyl you only connect the ground and 2 data wires RX and TX and keep the power wire disconnected. Except if you have a seperate UART port, this will go in the socket where your bluetooth module is currently conected.
@Louisvdw it only has one communication port on the BMS. This is the same port the Bluetooth connects to so should i connect the power also to the VeDirect cable?
 

Louisvdw

Solar Enthusiast
Joined
Dec 18, 2020
Messages
93
Ah wait. the VeDirect cable isolated, so you will need to connect the power wire as well. You will have to unplug the bluetooth cable and use that port for the USB converter. Use the same pinout as what the bluetooth cable used. Black and Red is ground and power. The other 2 is Rx/Tx. I'll look for a picture for you.
 

jamiegreen

New Member
Joined
Nov 8, 2021
Messages
67
Just out of curiosity and to save some trial and error, does anyone happen to know which of the 2 middle pins on the JK BMS GPS port is RX and which is TX? My USB converter lists white as as RX and green as TX but unsure on the pins of the BMS.
 

Martijn

Solar Enthusiast
Joined
May 6, 2021
Messages
141
Just out of curiosity and to save some trial and error, does anyone happen to know which of the 2 middle pins on the JK BMS GPS port is RX and which is TX? My USB converter lists white as as RX and green as TX but unsure on the pins of the BMS.
And how about the 3 pin connector? :)
 

jamiegreen

New Member
Joined
Nov 8, 2021
Messages
67
And how about the 3 pin connector? :)
Haven't looked properly but I think the 3 pin RS485 connector heads elsewhere on the PCB than the GPS port. So.. I literally no have idea what it does, is it mislabeled? Does it have a built in TTL to rs485? Either way I'll stick with the GPS port as JK do themselves. With that I know far right pin is ground and far left is +Bvoltage.
 

Louisvdw

Solar Enthusiast
Joined
Dec 18, 2020
Messages
93
Here is the connection. From that I would expect the pinout to be GND,TX,RX,Vcc
IMG_20211207_162436.jpg
IMG_20211207_162146.jpg
 

jamiegreen

New Member
Joined
Nov 8, 2021
Messages
67
Here is the connection. From that I would expect the pinout to be GND,TX,RX,Vcc
View attachment 74901
View attachment 74902
Unfortunately the newer style one with seperate ports is completely different, just following the tracks on the PCB the ground is definitely on the far right. Shouldn't be too hard to work out anyway, a 50/50 chance of getting Rx and TX the right way round, or maybe I'll ask the seller if they know 😀
 
Top