Brucey
Velcro Man
I would disable BMS control and just charge it up using voltage.
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
- Start date
XBeg9
New Member
- Joined
- Jun 4, 2022
- Messages
- 7
I will better move to https://mr-manuel.github.io/venus-os_dbus-serialbattery_docs/, this was working amazingly for anything that can't be handled on its own.
Has anybody tried this solution instead of JK fixing their poor code?
GitHub - Louisvdw/dbus-serialbattery: Battery Monitor driver for serial battery in VenusOS GX systems
Battery Monitor driver for serial battery in VenusOS GX systems - Louisvdw/dbus-serialbattery
github.com
^ That's the original. Works for quite some people.
Try charging with 30A or less. You probably have poor cable connection from inverter to battery + and -, you also have poor bus bar connections, you can see this in the high 'cell wire resistance's values. This results in big voltage drop. Probably you did not calibrate your JK and inverter regarding voltage. Measure voltage at inverter and at battery + and - with no load and see what difference there is. Then measure under 30A load/charging and compare difference, to get voltage drop on cables/connections.I am not getting, what am I doing wrong, or hit this JK-BMS weird issue... my charging stops too early, and turns into absorb
View attachment 251866
DVCC - enabled
CCL - 95A
View attachment 251867
View attachment 251869
You can see it here on charts... at 3.42 it just stop charging.
What's wrong?
Steve_S
Emperor Of Solar
Steve_S
Emperor Of Solar
WELL WELL WELL... Here we are Ending Week 3 of October and still ZILCH from JiKong and so much for NAMI's By October ! Who actually believed any of it ?
Not even another peep from Andy and the Mystery V16 HW Model. (which doesn't help the V14/V15 HW people).
Whatever, seems many are just giving up on JK outright for help/support or even a good "new" product.
I'm almost expecting a New Brand Label with all the goodies but looking terribly familiar (as in JK rebadged).
Not even another peep from Andy and the Mystery V16 HW Model. (which doesn't help the V14/V15 HW people).
Whatever, seems many are just giving up on JK outright for help/support or even a good "new" product.
I'm almost expecting a New Brand Label with all the goodies but looking terribly familiar (as in JK rebadged).
prosier
New Member
Would be very surprised. Would be nice though. I sent an email a while back. Crickets....
Brucey
Velcro Man
Looks like new hardware and "v5" is the future, thank you alpha testers...
Attachments
Nice photos. However appears to be more questions than answers at this time. Looks like it is not even compatible with the existing display screen if I heard right. Other versions were. Given JK's lack of response, not opening up my wallet anytime soon. Sounds like they might have their sights on the EV market. If that is the case not sure how much support we would get here even if one takes the plunge.
Brucey
Velcro Man
I don't understand much of the technical stuff there, wifi and 300A with surge to 700A were the standout changes to me. Not really an issue for the multi battery folks but if you are running just one or two big ones...also potentially more accurate soc tracking?
Will wait and see on the pricing I'm guessing the inverter comms units will be down at the OG non inverter pricing soon.
Will wait and see on the pricing I'm guessing the inverter comms units will be down at the OG non inverter pricing soon.
42OhmsPA
Who likes Electrical Gremlins?
Horsefly
Solar Wizard
It sure seems like instead of fixing the problems with a BMS line that has had a pretty good reputation, they've decided to throw it all out and start with a completely unproven design. Based on Andy's video, it sounds like they are trying to do balancing in a way that has never been shown before. There may be some translation issues, but this stuff about "SOC error within 2%" tells me that they still don't get SOC (@Nami's comments earlier didn't inspire much confidence). Sigh....
Yeah....nice photo, but no. We will not be their beta testers this time.
October 2024 is almost over and there is no news on the new firmware for V14 and V15 that fix existing issues. So much for upgradeable firmware
Steve_S
Emperor Of Solar
I watched Andy's video and honestly, I found some of the descriptions to be Translation Doublespeak from what Andy read & showed. New display, Comms-Board (retrofit current cases NOT), gonna be tricky with breakers as well... Not enough seen/known to really comment, but geez.... I guess everyone with V14 & V15 owners are sheep who just been fleeced. hey does anyone smell & taste that ? wonder what that is, hmmm
Anyone wanna lay odds on JKEMS gonna get screwy too ?
Anyone wanna lay odds on JKEMS gonna get screwy too ?
That's just because that's what the AFE (the MP2793) they use does. That's also why they use high-side switching in this BMS. For reference:
I quote "When paired with an MPF4279x fuel gauge, the MP2793 can achieve state-of-charge (SOC) error to within 2%."
MPF4279x reference documentation describes the SoC algorithm:
The main issue with these is that they have a dedicated chip per battery chemistry - this is the LFP one:
When I asked about the status of V15 firmware updates in the comments section of his video he has been silent. @Off-Grid-Garage if you still peek in here would be interested in an update IF you know anything.
Well, from his video, he mentioned something about receiving V14.23 firmware from JK, so that is something.....even though it is not v15.
Quattrohead
Emperor Of Solar
Andy has just admitted he has been duped by a different company pretending to be JK.
So no new JK BMS at all and no firmware upgrade.
But hey, maybe the imposter will be a better JK than JK
So no new JK BMS at all and no firmware upgrade.
But hey, maybe the imposter will be a better JK than JK
Well, I can respect him for the admission of fault/mistake..............Andy has just admitted he has been duped by a different company pretending to be JK.
So no new JK BMS at all and no firmware upgrade.
But hey, maybe the imposter will be a better JK than JK
RCinFLA
Solar Wizard
- Joined
- Jun 21, 2020
- Messages
- 3,862
LFP cells have an advantage for SoC measurement due to their relatively low overpotential necessary to drive the kinetics (ion-migration) within the cell. Temperature, or more specifically cooler temperatures, are a disadvantage as Lithium-ion batteries in general have a large change in their overpotential necessary to drive kinetics at colder temps.
In layman's terms, the electrolyte turns into 'molasses' with regards to lithium-ion migration through the cell at colder temperatures. This requires a rise in the required overpotential 'push' necessary to meet the necessary lithium-ion migration to meet the demanded cell current for a given load.
Higher lithium-ion driving overpotential means greater internal cell losses. Higher overpotential is required for greater cell current, lower cell temperatures, and as a cell ages.
Although often thrown into the bucket of cell internal impedance, overpotential is not really internal impedance in terms of I*R loss. It more like an energy toll tax paid to push the lithium-ions within a cell to meet cell terminal current demand. There are resistive losses internal to a cell from metal interconnects and other resistive losses which have losses that are a linear I*R relationship to cell terminal current demand.
If a rechargeable battery has no internal losses, then what goes in will come back out. Columb counting will accurately represent SoC assuming an accurate reference point is captured, which is usually a full charge. Unfortunately, such a battery does not exist, but LFP is close to the best there is at temps greater than about 15 degs C.
My personal opinion is achieving a true 2% running accuracy of SoC measurement is unrealistic.
This is due to the variable losses of the kinetics of a cell. The MPS paper just classifies this as internal resistance without accounting for the time aspect of cell current demand on kinetic losses. Shorter periods of current demand have lower cell losses per amp-sec than longer period of current demand.
Accounting for this is complicated and rarely done because there is so many dependent variables, such as current demand time period, temperature of cell, and aging of cell. Making it even more complicated is cell internal losses create internal heating which dynamically changes the cell temperature which dynamically change the overpotential losses verses internal heating time.
Then there is just dumb engineering. Ten 1 milliohm cheap surface mount chip resistors, parallel distributed across a copper interconnected, MOSFET heated PCB, make a terribly unstable 0.1 milli-ohm current shunt resistor. Garbage in, garbage out, for the Columb counter.
In layman's terms, the electrolyte turns into 'molasses' with regards to lithium-ion migration through the cell at colder temperatures. This requires a rise in the required overpotential 'push' necessary to meet the necessary lithium-ion migration to meet the demanded cell current for a given load.
Higher lithium-ion driving overpotential means greater internal cell losses. Higher overpotential is required for greater cell current, lower cell temperatures, and as a cell ages.
Although often thrown into the bucket of cell internal impedance, overpotential is not really internal impedance in terms of I*R loss. It more like an energy toll tax paid to push the lithium-ions within a cell to meet cell terminal current demand. There are resistive losses internal to a cell from metal interconnects and other resistive losses which have losses that are a linear I*R relationship to cell terminal current demand.
If a rechargeable battery has no internal losses, then what goes in will come back out. Columb counting will accurately represent SoC assuming an accurate reference point is captured, which is usually a full charge. Unfortunately, such a battery does not exist, but LFP is close to the best there is at temps greater than about 15 degs C.
My personal opinion is achieving a true 2% running accuracy of SoC measurement is unrealistic.
This is due to the variable losses of the kinetics of a cell. The MPS paper just classifies this as internal resistance without accounting for the time aspect of cell current demand on kinetic losses. Shorter periods of current demand have lower cell losses per amp-sec than longer period of current demand.
Accounting for this is complicated and rarely done because there is so many dependent variables, such as current demand time period, temperature of cell, and aging of cell. Making it even more complicated is cell internal losses create internal heating which dynamically changes the cell temperature which dynamically change the overpotential losses verses internal heating time.
Then there is just dumb engineering. Ten 1 milliohm cheap surface mount chip resistors, parallel distributed across a copper interconnected, MOSFET heated PCB, make a terribly unstable 0.1 milli-ohm current shunt resistor. Garbage in, garbage out, for the Columb counter.
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chicagoandy
Solar Enthusiast
Hope you saw this in the description of Andy's video:
"It turns out, this JKESS BMS is NOT made by JKBMS/JIKONG like all the other JKBMS we have tested and used for years (BD and PB series)!
The JKESS BMS was sent to me by the JKBMS Official Store on AliExpress which is a distributor for JIKONG products, but this new BMS has nothing to do with JKBMS or JIKONG. It is a totally different product and not linked to, made or designed in any way by JKBMS or JIKONG.
At the time of making this video, this was not clear to me. For a few months, I had in-depth discussions with the distributor about this JKESS BMS. At no point, I was told, that this is NOT a new JKBMS product.
It looks like a JKBMS, it feels like a JKBMS, but it is NOT a JKBMS. It is a fake and counterfeit product. Unfortunately, the JKBMS Official Store tried to use the popularity of the genuine JKBMS (BD and PB series) to advertise, market and sell this product through their channels and I was fooled to believe it is a new genuine JKBMS. I apologise for making these false claims here in this video and platform, but it was unknowingly at the time of recording. At this point, we will not further explore or test this product.
I have spoken to the founder of JKBMS/JIKONG and they are still committed to further develop the firmware for the existing inverter BMS, both V14 and V15. I will keep working with JKBMS/JIKONG, providing feedback and testing new firmware versions.
"
Steve_S
Emperor Of Solar
While it may be a Fake JK it's not something some kid glued together in his bedroom out of scrap parts.
Ohhh, the fodder for Postulation, Theorization & Conjecture.
So much for NAMI's "By October" statement...
Anyone left feeling any sort of Love towards JK anymore.
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chicagoandy
Solar Enthusiast
Or at least put a disclaimer at the start of the video. That he's buried this in the description means many people will miss it.