My config.
I have succesfully connected my JK BMS to my cerbo.
I use 2P16S LFP batteries, victron smartshunt, cerbo and multiplus ii.
My PV is AC connected to the multiplus out.
I use dynamic ESS.
When the battery is charging all is well but as soon as the battery reaches 100% the JK BMS issues a lot of High voltage alarms (on the cerbo and VRM).
ASfter an hour or two it stops giving errorts and all is ok again.
Cell OVP in the BMS is set at 3.65 volt.
DVCC is now set to:
DVCC: on
Limit charge current: on
Max charge current: on and set to 150 amps
Limit managed battery charge voltage: off
SYS: on
STS: on
SCS: off
How can i make this error go away?
Should i change the maximum absorption time in multiplus (now on 2 hours), change dvcc settings or set something somewhere else?
Remote Console → Devices List → JKBMS (find the correct name on your list) → Details
There you should see how many banks BMS reports to Victron (online/offline), and how many of them blocking charge/discharge.
If there is only one reported, check addressing on BMS connection board. Main should have address 0 (all dip switches down), second 1 (first dip switch on the left up).
Nice
I had them on 1 and 2
Now i see 2 batteries.
This allready solved the ‘battery modules’ thing.
I set them (i think) according to advice from te guy from offgrid garage to 1 and 2, (but not shure). Now on 0 and 1 they are both visible in cerbo.
I also changed (before i read you’re reply) the absorbtion voltage in the mp from 56 to 55.2 volt. As i have read in a victron manual today.
Both batteries are now on charging ON status, but cerbo has started dumping to the grid (DESS) so i will have to wait till tomorrow to see if with the new voltage in the mp the problem is gone i was under the assumption them when mp is under jk bms controll all the setting come from the bms. But maybe not?
I will absolutely report back tomorrow when the batteries are charging again
Or is it wise to change other stuf to first?
Hi,
Since i made the change of the battery id i now also see both batteries in my jkbms windows program (i have them connected to my PC via rs485). But i can now not select any buttons on top (realtime, settings, controll etc). So maybe i can now only make changes via BT? Seems illogical to me. I have surched for an option to activate the buttons, but can find nothing. Can you help?
The problem with JKBMS is with the address (dip switch) vs. RS485 settings.
When you want to configure BMS, it is the best when you disconnect them from the CAN and RS485 chain. The BMS you want to configure, should have address 1 or higher set on the dip switch to be able to configure it without any problems - windows app is not accepting 0 as a connection address, so you will have problems to connect to the master one.
If you want to only preview the parameters, you may connect RS485-USB interface to the chain RS485 port. Then you will see the tabs for each BMS connected.
Personally I’m doing configuration via BT because it is not affecting connection between BMS chain and between master BMS and Victron.
At least in earlier versions of the Windows program, changing settings did not work. The Windows program should therefore only be used for firmware upgrades and settings should only be made via the Bluetooth app.
It may be that the latest Windows program version is now also able to change settings, but I have not yet tested this. To be on the safe side, stick to changes via BT.
Have you seen all the videos from Andy’s Offgrid Garage regarding JK Inverter BMS? They mention it there too
Arek,
Today, my battery did only reach 91%. I assume it has something to do with the setting i changed
I have the bms and victron now on the voltages you adviced. Now i have to wait what happens tomorrow i will report back.
RCV was allready on 3.6 volt
RFV was on 3.5 volt, changed it to 3.54 volt.
For both batteries of course.
Victron absorbtion was on 56 volt. Changed it to 57.6. Rather high i think, but let wait and see.
Victron float is now on 56.64.
But i still do not understand: does not the bms determine voltages though the can port? Overriding the settings in mp?
Today i again did not reach 100%.
A bit weird because dess should charge to 100% from grid, but maybe there are some deeper reason’s why it decided not to charge to 100%.
Anyway, i still did not find out if your settings work not to let the bms reach OVP.
Tomorrow is very sunny here, should be good test day. Hope you are still following this.
OVP is Over Voltage Protection and it is a parameter on the BMS to not cross the safe battery Voltage.
Keep Batteries Charged should just charge them to 100%. No impact on OVP.
But you now have DESS when you are not sure how the rest of the system is working - and is it working properly.
So I suggest to disable DESS, to have automated logic disabled and focus on proper setup of the system to work as simple ESS. To just charge the batteries from the sun and discharge them for your home needs.
Setting DESS for selling or buying the energy based on dynamic rates is another step. When the system will work predictably.
Thanks tor the reaction.
I know what all the abriviations mean.
I have been running ESS for a few weeks and there were no problems.
Since i switched to DESS the OVP trjggers.
Going back to ESS only would probably not add anything to solving this.
Today i again reached ovp.
Lots of errors while battery switches from blocking to unblocking charging.
Looks like your settings didn’t help.
Witch is logical i think because they were higher then the onces i had set. But i had to test.
Question remains: why doesn’t jkbms throttle charge so it does not reach ovp?
Any other advice of things i could look into?
The other thing you may check is the Voltage Delta when the alarm is triggered. Maybe your cells are poorly balanced and one of the cells is charging way higher than the others. Settings I posted are working nicely, but when you have properly balanced cells initially.
