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JKBMS Inverter Edition Problems/Issues | No Support / Help to fix major issues. - DO NOT BUY ! Warning (as of Oct.12.2024)

Well, another problem with this BMS is that the balancing is nowhere near the advertised 2A. It loads a capacitor? for about 35 seconds and then discharges at 2A for 15 seconds. This only gives and effective transfer rate of roughly 0.5A. That's a bit of mismarketing that I am really not happy about. I've been running my setup at 3.38V all day and it hasn't got rid of a .03V mismatch. That's a 27W transfer rate :< I purchased this thinking I wouldn't need any kit to top balance.

Purple line is the difference. mV scale to right
Red line and blue line (max/min cell voltage)
Screenshot 2024-11-30 at 16.38.17.png
 
I run my packs with JK's and only 1A balancing - they stay in balance as long as you take the time to top balance the pack before you start running them in the ESS solar set up.
The initial balance is an important step, since the cells are huge capacity compared to the balancing energy available, unless you want to take several months to achieve the balance you can get in an afternoon.
 
I run my packs with JK's and only 1A balancing - they stay in balance as long as you take the time to top balance the pack before you start running them in the ESS solar set up.
The initial balance is an important step, since the cells are huge capacity compared to the balancing energy available, unless you want to take several months to achieve the balance you can get in an afternoon.
I wanted to avoid buying a charger 😂 But good to know once there it will be fine. 80 Cells to top balance though :<
 
You can avoid, perhaps.
Use the solar set up to bring all the packs up to 100% SOC including the new pack that is not balanced.
Pull that unbalanced pack out of the ESS, open it up, check for the highest voltage cells in the set.
pull the voltage down on those high cells with an automotive bulb or similar DC load. Monitor the cell voltage with the BMS or a DMM.
Work your way through the cells until they are all very close voltage per cell.
Return the pack to the ESS and monitor.
I find a high cell when loaded with a bulb to pull down the cell voltage will re-bound somewhat once you remove the load. So you may need to over-shoot the voltage a bit, to allow it to rebound and land close to the other cells.
 
Didn't know we had anthropomorphic electrical devices.
I wanted to avoid buying a charger 😂 But good to know once there it will be fine. 80 Cells to top balance though :<
I never bothered charging mine and the JK BMS has had no issues balancing a 280Ah and 560Ah banks. You need to give it a bit of time at first and not expect it to balance it immediately.
 
I've been running my setup at 3.38V all day and it hasn't got rid of a .03V mismatch.

You shouldn't balance at 3.38V, that's still in the flat part of the curve. Balance at 3.45V starting, or even take it to 3.5V.

I use the 100A JK with 0.6A balancing current and don't top balance anymore beforehand - just put them together and the BMS takes care of it.
 
You shouldn't balance at 3.38V, that's still in the flat part of the curve. Balance at 3.45V starting, or even take it to 3.5V.
I appreciate that thanks :) . I found that the within about 10 minutes I'd hit 3.45 from the current voltage. I didn't want it sitting at too high a voltage whilst balancing forever. I've got my software slowing down the charging rate whilst it balances and then it will let it go higher on the voltage once within .01V. I'm abandoning the JK control and doing the absorb/float myself with tail current. I've written the control software for a Victron setup. I think I'm just going to order a charger. This setup has been going for 5 months now and it's still not balanced. The trouble is there are only so many hours a day where it is at 100%.
 
I've just done 4 packs of 280 batteries with the jk-bms with no problem at all. Took them to 3.45 and then finally 3.5.
 
I wanted to avoid buying a charger 😂 But good to know once there it will be fine. 80 Cells to top balance though :<
I top balanced all my packs with solar/6000XP inverters, just turned off discharge in the BMS and adjusted voltages as they charged, took a few days to get 4 306ah packs fully charged/balanced, now they are within 0.000 - 0.005v variation between cells within each pack as they discharge and recharge etc.
 
WELL Here we are, December 01 and progress is ??? Officially nothing...
Thank Goodness that Open Loop does not mess up charging & floating when handled externally.

At least my packs in the bank are operating well and the Active Balancing etc are all doing exactly as they should.
Still gives me a Huge Smile when I see ALL Packs with cells at 3.425 and with no deviation greater than 0.005mv. Most especially because I have V1 to V3 EVE 280AH cells dating from 2018 to this summer all within my bank. Even more Smilage is that there are Bulk, B & A Grade Matched cells making up the packs in the bank.
 
What do you mean ‘when handled externally’? You mean the inverter just using voltage?
Solar Charging profile is driven by a Midnite WizBangJr that controls Absorb to Float transition using EndAmps/Tailcurrent. My Solar is Midnite Classics & and using Samlex EVO Inverter/Charger.
 
Here in California, the voters again rejected abolition of slavery.

SMA documentation now says "Primary" and "Secondary", but inverter menus retain the traditional "Master" and "Slave".
The slaves are required to do what the master says.

I think our JK BMS is set to #1, "1000" DIP switch settings. Worth a try if nothing else works.
The posts up above a few are correct from what I know. Since there’s 4 dip switches, there’s a maximum of 16 JK BMS that can be connected together for communication. The “master“ or “primary” BMS (which I call battery 1) has all the dip switches in the off position. I.e. 0000. Then batteries 2 through 16 ave the dip switches correspondingly changed. Might as well get used to it now. When you go into the Phone app it also lists each BMS serial number with the dash 00 or – 01 etc. 00 is the first battery, 07 is battery number 8. 15 would be the last battery or number 16. I put a sticker with the DIP switch number on each BMS so I know which battery I’m looking at on the phone. Just to avoid confusion. But you get used to it.

When you use the PC app, there could be some Inst ruction where you have to change dips switch to one, but I’m not exactly sure. For normal usage the first one is zero.
 
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We have a Sunny Island set up here and we’re using 15.24. Seems to be working OK and just wondering. I was advised that JK seemed to mess up every other firmware update and to leave it alone for a while. For us, it would be a question of if anyone else is using 15.33 with Sunny Islands successfully.
 
We have a Sunny Island set up here and we’re using 15.24. Seems to be working OK and just wondering. I was advised that JK seemed to mess up every other firmware update and to leave it alone for a while. For us, it would be a question of if anyone else is using 15.33 with Sunny Islands successfully.
Yeah, not using Sunny Islands but I haven't had any issues. I normally run mine in open loop. I have tested closed loop though and not had any issues to report. I would say the one thing I still am seeing is SOC drift when there's not a fairly frequent full charge. (I'm comparing that to my SmartShunt as a reference). The JK still seems to be about 2% optimistic.
 
Boy what a Web oh Hooey has been woven. Considering what Nami was saying to both myself & UpNorthandPersonal when we were both editing the previous Manual for the "Black BMS'", that thick layers of "stuff" back in July 2022 I'm not surprised...

So WHO really owns the "Official Site" ? http://www.jkbms.net
And WHY does it list "These People as Contacts": Helen@jkbms.net, Seven@jkbms.net, Sandy@jkbms.net, Miranda@jkbms.net, Ross@jkbms.net, Nami@jkbms.net ?? None of which who EVER Respond to an email !

Note there is quite a difference between JKBMS.NET and https://jikongbms.com including in their DOWNLOADS SECTION !, Contact Info and more... Look at the Manuals, Information and material on JiKongBMS.COM and it's far more complete, informative & "Professional" !

Every time something else comes out about JK I feel a need to wash and get clean again.
Back when I was doing my research in July, I was trying to figure this out myself. From what I understand and I could be completely wrong, jkbms.net is the factory that makes the product. They also have a trading company which operates under the Jikongbms.com. Both sell the products in both claim to be the original factory. I ended up going with jkbms.net. Not to say that the trading company wouldn’t be OK to buy from either. Then, of course there’s all the sellers on all aliexpress and Alibaba who sell the JKBMS. And with similar names. Hard to say what’s real over there.
 
I’ve made good progress over the last couple of days — RCV correctly set after carefully reviewing Andy’s settings video, and I’m communicating with the PC App via a USB-RS485 cable.

Well… sort of. I have two batteries in parallel. I have disconnected the master from the CAN connection to my Cerbo, disconnected the second battery, DIP switches set to 0000… But the PC monitor app only sees it as device 0 in the “parallel” tab.

Which seems to limit my ability to do anything to it, or access the full suite of features in the app. I can’t get the about tab to display, for example, and the main reason for needing the app — updating firmware — doesn’t want to work either.

Any ideas as to why I can’t see the BMS as a standalone unit, rather than on the parallel screen?

Thanks! Andrew.
 
NEW FIREWARE
.....hmm.....wonder if this fix the 100% -->99%--->100% continuous rebulk-float-rebulk instead of waiting for the RFV Timer to expire?

edit: Ah....screw this, I just went and updated both V14 and V15
Screenshot_2024-12-06-17-36-02-052_com.jktech.bms.jpgScreenshot_2024-12-06-17-40-35-278_com.jktech.bms.jpg

Finally after more than 1 year, V14 hardware finally got a firmware update........

Will not be able to test the 100 SOC%, RFV/RCV Timer etc.....monsoon season and it is raining non stop and cloudy for almost entire week now...
 
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@AshleyL Top Marks for Bravery !

Hmmm 15:35 posted here, nowhere else, not a peep anywhere (yet).
Standing by to Read what people have to say.

The "Change Log" such as it is... Just the 15:33 & 15:35 portions.

Current JKBMS Droid App
Published at 2024-11-24 Version 4.29.0 Build 38

* NOTE * The Incompatibility with sub-versions of Android is Back and it "may" not install from Google Play.

V15.33 Upgrade logs
1.Fixed a Bug with Victron inverter about energy consumption.
2.Fixed the bug of entering float charge.
3.Optimized the logic for SOC100% reset to Solve the bug that some inverters use SOC to control charging.
4.Fixed the bug where DRY2 failed.
5.Add one key to set Lion, LFP, LTO log recording.
@2024-11-04 by JKBMS

V15.35 Upgrade logs
1.Optimized ampere-hour integration algorithm to improve SOC accuracy.
2.Optimized SOC reset logic to 100%. After the absorption timer ends, if BATVOL > VOLSOC100%*CELLCOUNT , the SOC is set to 100%.
3.Added logic to enter float mode.
After the absorption timer ends, if BATVOL > VOLSOC100%*CELLCOUNT,
the BMS enters floating mode. Otherwise, the device enters bulk mode again.
4.Running parameters add the current charging status (Bulk, Absorption, Float), RCV Timer, RFV Timer display (mobile phone APP needs to be updated).

@2024-12-06 by JKBMS
 
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