@Steve_S out of curiosity what other brands are building new a BMS with similar capabilities?
JKBMS Inverter Edition Problems/Issues | No Support / Help to fix major issues. - DO NOT BUY ! Warning (as of Oct.12.2024)
- Thread starter Steve_S
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Steve_S
Emperor Of Solar
I've heard of 3 that are supposedly working on it but that's classed as advanced rumour. I think it has to happen as progress is ongoing like competition. Personally, I have swapped BMS' enough times over the years, I've had my fill and not interested in replacing my fleet unless I absolutely have to. I already have a couple of large boxes of stuff all headed to the recycle bins.
OffGridForGood
Catch, make or grow everything you can.
Has the problems with JK now expanded beyond the Inverter-edition !
I have a new DIY battery I am putting together, with a Jk BD6A20S10P but this BMS is messing up:
1. I changed the P/W "In Time" from the default to all 1's but it doesn't accept the change (???)
2. I changed the silly factory parameters to normal LFP settings - but it goes back to the factory settings all on it's own. (???)
Did I miss a memo somewhere ? What am I doing wrong @Steve_S ?
I have a new DIY battery I am putting together, with a Jk BD6A20S10P but this BMS is messing up:
1. I changed the P/W "In Time" from the default to all 1's but it doesn't accept the change (???)
2. I changed the silly factory parameters to normal LFP settings - but it goes back to the factory settings all on it's own. (???)
Did I miss a memo somewhere ? What am I doing wrong @Steve_S ?
Steve_S
Emperor Of Solar
Sorry, no clue - sounds pretty darn messed up to me, as this sort of thing is the first time I've heard something like this. But in all honesty, I've stopped watching & interacting with much of this now days....
samir101ng
New Member
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Happy New Year Steve. Appreciate all that you do Man.
OffGridForGood
Catch, make or grow everything you can.
understood, Steve.
I think I have bumbled my way through it, with an update to the JK app - now it pairs and lets me adjust settings.
God, I was terrified for a moment there, I have SEVEN of these JK's running in my ESS...don't want them to fail me!
So - what is the verdict, do we transition to JBD BMS? Overkill?
42OhmsPA
Who likes Electrical Gremlins?
My contactor JBD (Just Balance Damnit)s have been flawless except for the piss poor SOC tracking.
.... Oops, wrong thread. Sorry Steve.
Cheers to an amazing 2025 with a new kick ass BMS, hopefully.
OffGridForGood
Catch, make or grow everything you can.
I have no spares now, so I am primed to buy a stack of new BMS's for 2025 DIY battery builds...But Which One?
- I don't care if the BMS SUCKS at SOC tracking - the Victron smart shunt has this covered and reports to Solar Assistant.
I just want a BMS that I can pull up the individual cell voltages once in awhile to check on the delta, tweak settings here and there, keep the cells in line in the normal daily cycling function, and give me 100A output. Even if limited to 50A charging is fine because I have so many packs.
One vote for JBD - anyone else ???
- I don't care if the BMS SUCKS at SOC tracking - the Victron smart shunt has this covered and reports to Solar Assistant.
I just want a BMS that I can pull up the individual cell voltages once in awhile to check on the delta, tweak settings here and there, keep the cells in line in the normal daily cycling function, and give me 100A output. Even if limited to 50A charging is fine because I have so many packs.
One vote for JBD - anyone else ???
sunshine_eggo
Victron's little biatch
Big JBD fan, but I've never tried JK, and I'd like to. JBD charge/discharge ratings are typically symmetrical.
I will take the opportunity to say... DALY is ass.
OffGridForGood
Catch, make or grow everything you can.
Until recently I have never had an issue with the JK's - but am feeling a bit gun-shy after the whole Deye-brick-gate thing.
Maybe best to NOT have every single DIY pack using the SAME BMS, maybe better to use two different makes...
So the new ESS1 & ESS 2 are side by side each with their own main breaker. ESS1 is now full and is all JK BMS's.
Thinking of going to another brand for ESS2 and keep some options open / be less vunerable to issues...
thats 2 votes for JBD ...anyone else?
alcook62
Don't Be A Casualty - Cut the Cord
I'll make that three. I've never had any negative issues with the JBD. I'm running two Overkill JBD clones and one straight JBD bms.
My Overkill experiences were a little more disappointing and one ultimately failed. Reason I went with JK technology which for me has worked much better.
While the door was opened to suggest other technologies might I suggest another thread for this so this thread can stay on topic.
While the door was opened to suggest other technologies might I suggest another thread for this so this thread can stay on topic.
jorby
Solar Addict
I have 4 of the JK-PB2A16S20P that were bought mid-November. I have no complaints with them so far. v15.30 I believe. The SOC seems more accurate, and track better, than the 13 JBDs in my rack batteries. Balancing works great too. The JBDs don't play well with Solar Assistant without connecting EVERY battery via rs485, but the JKs all show up with just one connection from the JK parallel bus.
OffGridForGood
Catch, make or grow everything you can.
I have eight JK BMS - and the switch to something else IS ON TOPIC ! 
I ordered four JBD's 125A 16s (actually they are 14-17 variable) will try these out for the next few battery builds and see if I like them.
Thanks for everyone that commented.
edit to clarify - I mean the non-inverter edition.
I ordered four JBD's 125A 16s (actually they are 14-17 variable) will try these out for the next few battery builds and see if I like them.
Thanks for everyone that commented.
edit to clarify - I mean the non-inverter edition.
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Which JBD? I was looking at these for a bit but didn’t buy any yet. Was waiting to see how the JK firmware played out.
North Forker
Avoid the Magic Smoke!
Oh Lordy, just when I order a couple bms and think you know some workarounds for JK. I guess I have a LOT of reading to do. I’m building two 48V 314ah banks with MB31 batteries. Is there a short list of bms brands solutions or is it really a use what works for you landscape? Yes I’ve searched here but still hope to get some feedback. Zip me a message if it’ll keep this thread on track thanks!
JK BMS's have been working fine for me so far in 6 15kwh diy batteries (MB30 cells) and I have 5 more to put together yet.
Horsefly
Solar Wizard
Having used JBD and Overkill before, I also am happy with the non-Inverter-comms version of the JK BMS. I did have one that failed years ago due to a design flaw that the pretty quickly fixed. I know some people say active balancing is not needed, but my experience is that the passive balancing used by the JBD / Overkill just doesn't cut it for the grade B cells that most of us have been dealing with. The active balancing of the JK works perfectly. (I know this thread is about the inverter edition, but thought I should speak up for the other JK models).
OffGridForGood
Catch, make or grow everything you can.
Most of my JK's are only 0.6A and work fine, but like you say "better" cells make this easier.
Had some recent issues with JK, so ordered some JBD to try out. I don't want to put too many eggs in one JK basket.
Lesson 1 from using firmware 15.35 with parallel batery packs:
Set all slaves pack RCV lower than the master RCV. The inverter will use RCV from master BMS anyway.
Do the same with the SOC100% Volt and RCV Time too.
Otherwise those slaves batteries will never reach 100%. The timer at each BMSes are "fighting" each other, or some sort of race condition.
Example, if the Master BMS RCV Timer expires and it switches to RFV, the other slave batteries with 1 - 5 seconds or slower timer will not set the % to 100% because battery voltage will quickly settle down to RFV and doesn't fulfil SOC100%volts condition.
Set all slaves pack RCV lower than the master RCV. The inverter will use RCV from master BMS anyway.
Do the same with the SOC100% Volt and RCV Time too.
Otherwise those slaves batteries will never reach 100%. The timer at each BMSes are "fighting" each other, or some sort of race condition.
Example, if the Master BMS RCV Timer expires and it switches to RFV, the other slave batteries with 1 - 5 seconds or slower timer will not set the % to 100% because battery voltage will quickly settle down to RFV and doesn't fulfil SOC100%volts condition.
These settings are master BMS?
First thing, ensure all battery pack BMS voltage are calibrated to match each other.
In parallel configuration, after the current is no longer flowing into the battery during charging, the battery voltage for each packs should be the same value.
For the slave BMS, set SOC100% to 3.442V (lower than the master BMS 3.445v), Volt Cell RCV to 3.445V (lower than master BMS 3.45V) and finally RCV Time to 0.1 . Remember, the "controlled float charge" mode is totally depending on Master BMS and not Slave BMS.
My BMS reaches SOC 100% only when float mode is turned off.
RCV timer value 0.1H.
The cell voltage values have long exceeded SOC 100%, several hours pass and float or SOC 100% do not start.
How to solve this problem? Software 15.37
RCV timer value 0.1H.
The cell voltage values have long exceeded SOC 100%, several hours pass and float or SOC 100% do not start.
How to solve this problem? Software 15.37
Indeed, I just saw 15.37 is on Andy's (Off Grid Garage) google drive. Just put this on all 5 of my batteries and going to run another round of some testing.
They've added some more status values to the app (which should update on iOS, I can't speak to Android). PACE and WOW protocols now work as well - no BMS boot loops. I've set mine to WOW since I have SRNE inverters.
@yur43 Are you saying/suggesting that we need to turn off the float mode switch, or just for versions prior to 15.37?