Growatt SPF5000ES with the new JK BMS

[Ezo]

Hi.

I have tried to setup the communication via CAN or RS485 without success.

1. CAN

There is no pin pair where to measure ~100 - 140 ohm. The manual says 12 and 13, but my JK doesn't show any resistance.

12 is actually the fourth pin
13 is actually the fifth pin

2. RS485 to Growatt

The JK manual says either pin 1 and 2, or pin 7 and 8. The only pair having 140 ohm is 7 and 8. Therefore I made a cable connecting 8 with 1 and 7 with 2. Because Growatt has 1 and 2 reserved for RS485. Then I tested and it doesn't work.

3. RS485 to desktop

I went to the second location where I have a Seplos installed and I took the desktop used to communicate with Selpos using this protocol. So with an adapter that works with Seplos and with JK software, I tried all the RS485 ports of JK. Guess what: it doesn't communicate with the BMS. The COM3 is getting connected with the desktop, however the BMS doesn't send any data.

No issue with Selpos using the same hardware.

Who can give me details from personal experience?

Thanks

 

[Ezo]

I have set the Growatt protocols in BMS for both CAN and RS485. Saved.
I changed the device address from the dip switch several times.
I changed also the device address in inverter: menu 5, LI, 51-65 for CAN or 01-15 for RS485. Error 20 always.
The device addresses were different every time, inverter address versus BMS address.

What else?...

 

[nc73]

Never had any luck setting comms with jk bms, some have been successful. Don't really need it.

 

[timselectric]

Never tried.
No idea.

 

[Ezo]

I just wanted to connect the desktop only to see if RS485 ports are sending anything.

I just need to see the battery capacity percentage on inverter / phone app.

I forgot to mention I have LCD display in the system. Someone advised to remove it, to free some kind of slot... Never tried.

 

[timselectric]

I really have no idea. I don't do any closed loop comms.
Hopefully someone else can help.

 

[AshleyL]

I just wanted to connect the desktop only to see if RS485 ports are sending anything.

I just need to see the battery capacity percentage on inverter / phone app.

I forgot to mention I have LCD display in the system. Someone advised to remove it, to free some kind of slot... Never tried.

Desktop connection? Then review by Andy from offgridgarage might help.

Start at 24:00. Communication with desktop seem to required the first DIP switch to be pushed up to ON state while the rest at OFF state ?

I have Growatt SPF 6000 ES Plus inverter and "was" using the RS485 communication via the new JKBMS......with bad result.....
First, I set the UART1 to growatt rs485 protocol, then set all the DIP switch at the communication board to bottom.....or off position?
Then I plugged in a LAN cable to the RS485-1 (refer to the screenshot) and the Growatt BMS LAN port.
Finally, at Growatt Inverter, I changed Program 05 to LI and select Protocol 1 and push enter.
I can't remember if I pressed the "reset" switch first at the communication board before I changed the Program 05 to LI.

Important note: If you use the JKBMS inverter communication, I must warn you that the JKBMS will instruct Growatt to STOP CHARGING if any of the cell reached OVP(overvoltage) value and WILL NOT RESUME CHARGING even though the cell voltage dropped below OVPR (overvoltage recovery) value. I was wondering why in the world my 280AH lifepo4 battery was giving me such a low capacity before I realised the issue.

 

[Ezo]

Hi, Ashley.

Super thanks! It worked from the first try, my inverter tells now the capacity percentage. Also the warning is much appreciated. But I assume that after the total voltage decreases the inverter will be allowed to charge. ) Let's see. I have some 8A equalizer which should keep the cells aligned fine enough, to overcome this issue.

As for the desktop link... Nope. I knew the video, perhaps the only film made about the new JK. On my phone app I cannot modify the UART1 to 1 because it cannot be saved for some reason. Perhaps with the next firmware, who knows.

Cheers!

 

[AshleyL]

Hi, Ashley.

Super thanks! It worked from the first try, my inverter tells now the capacity percentage. Also the warning is much appreciated. But I assume that after the total voltage decreases the inverter will be allowed to charge. ) Let's see. I have some 8A equalizer which should keep the cells aligned fine enough, to overcome this issue.

As for the desktop link... Nope. I knew the video, perhaps the only film made about the new JK. On my phone app I cannot modify the UART1 to 1 because it cannot be saved for some reason. Perhaps with the next firmware, who knows.

Cheers!

Good to hear that it works on your first try.
Hereby lies the problem. If any of the cell breaches OVP value, JKBMS will change the SOC percentage to 100%.
JKBMS will only instructs the growatt inverter to start charging again at 95% (via Coulomb Counting Method after 100%, assuming if you set your AH value at JKBMS app and it is VERY UNRELIABLE if there is runner cell or unbalanced pack). Do not trust the percentage SOC.
Granted that your Growatt SPF 5000ES will start to use battery to power up its own system and recharging should start after 3 - 4 hours again, if it works at all?
There is no "float" or absorption period in BMS-inverter communication. If you are the type that top balanced at 3.4v and above, you might find this an issue as there is no time for the active balancer to work its magic.

Plus, there is weird issue with jkbms. If you set the Continuous/Continued Charge Current to 66A, you will notice jkbms will instruct the inverter to charge at 60A. Try to set Continuous Charge Current at jkbms app to any value and you will notice the value at Growatt Program 02 "CHGI" will always be a bit lower.