Hey Andy, Merry xmas / new year. Check for contact between the current limiting coil and the BMS front plate, I found several of a particular batch that had contact between the winding that returned to the PCB and it causes this issue, you will notice the later generation has heatshrink covering the coil totally, ive also seen what can happen if this is not caught before commisioning. You can gently pry this coil away and heatshrink. Also, this wiring issue / arrangement of balance cables has never been apparent on any batches we have purchased for the business 🤔
@@nzlithium1352 confirmed! The winding of the coil was indeed touching the front panel. I pushed it away and rearranged the coil a bit and problem solved! I'll talk to Jikong if they can make this round cutout a bit wider. Thank you.
@@OffGridGarageAustralia likely no need, if you take a look at your other one with heatshrink over the coil, they realized the problem and solved it, albeit there will be several BMS with this issue in commision, and it can be a nasty outcome in the right situation. . .
A few weeks ago, I stumbled on one of your video while looking for a review on a bms. I got attracted by your german accent (Es gab eine Zeit, in der ich Deutsch sprach) and I have learned a lot through your videos. I finally orderded a V15 JK inverter bms that I just tested yesterday. Working on a self consumption system using grid as partial storage (injection tarrif are good here) to lower battery volume. So far so good, integration with both victron (cerbo gx) and sma sunny island is underway thanks to your very informative contents. Thanks again from Dakar , Sénégal, and keep it up.
Yes, I also think that is the Problem. If you look in the Video (at 20:14), than you can see the ring lug on the minus touching the cover of the bms. Sunny greetings from Austria! Robert
I was going to say the same thing. I think this is self inflicted. Congratulations go to him for spotting the problem when he got that tingle and not just ignoring it. That’s a good lesson for the young ones to learn. If you see/feel/smell something not right, stop and make sure you fully understand or correct the problem before continuing on.
Hello Andy Thanx for all your inspiring video's. Just some info regarding the coil theme: I looks like the 100A V15 models are at least in two ways different from your V14 model. 1 - the (current limiting) coil is already wrapped in heatshrink 2 - there are 4 screw terminals instead of 2.
Hi Andy, I think the reason for the cell wiring is when you sepperate the battery in two there is a cable between cell 8 and cell 9 and no bussbar. And now you can still measure de cells and dont measure the voltage drop of the connecting cable. Keep up the good work Andy!👍🏼
Yes, that was with the older style battery where we had a fuse between bat8 and bat9. Hence they uses an additional balance cable for a 'fake' negative in case the fuse tripped to have 2x 24V batteries with a 'main negative' each.
In the last video I wrote that Gobel boxing is not the best. But after watching this video - THESE ARE THE WORST cases that exist. Thanks Andy for your work.
I love both of my Gobel boxes. I had none of the problems that Andy has had and I fully recommend Gobel. Their MB31 cells are excellent. I trusted Gobel enough that I wired the money to them instead of using a credit card, knowing that if anything went wrong, I would have no recourse. I was not disappointed.
The ring lug on the minus coming from the battery is very close to the heatsink and if it has connection the heatsink becomes minus and then the screw holding the bms is touching the heatsink and then the case becomes minus potential.
@@OffGridGarageAustralia It looks like the lug of the wire to the right may be touching the heat shield. Try with the lug pointing up instead of to the right and I bet the issue goes away.
@@OffGridGarageAustralia i agree with what he said. It may look different to you, but in the video the lug looks like its giving the heatshield an intimate massage. We cant see as well as you can since were not there, but do take a closer look at it. Edit: see 20:43 left lug is fine, right looks questionable.
Hi Andy. Loved the video as usual, but I have to point out what many have already pointed out. The right lug coming off of the BMS negative is touching the the BMS case. If you were to put the right lug on top of the left lug instead of the way it is in the video (right lug under left lug) this would raise the lug up and away from the BMS case. I have also read your responses in that you say this is not the fault. I work on domestic appliances and sometimes the obvious may not seem obvious at the time and as we get frustrated we talk ourselves into believing the module is faulty when it is not. In my experience the chances of having 2 faulty modules one after the other like that is almost impossible odds. I suspect both BMS's are ok. The first one because of the issue with the balance cables issues (plus it has a completely different firmware version which could affect the outcome) and the second one because of the negative lug touching the BMS casing. I know it takes time but I would reconnect your original BMS now that the balance cables are rectified and see it it works normally and I would also reconnect the second BMS and watch you video back and attach the negative cables exactly the same and test the following - Between the battery negative and the BMS case you would have continuity (possible faulty BMS or something touching somewhere). or - Disconnect negative lug from the BMS and measure continuity when the between negative terminal on the BMS to the BMS case. (If there is no continuity then it's NOT a faulty BMS, if there is continuity then it IS as faulty BMS).
Thank you again for a great video. Just think of the pain one would go through if they had to wait for a new BMS to be shipped out each time, all that while still needing power for their OFF GRID system, remember some of us have NO GRID.
Hey man great video. I have a small system that I built watching your video 3-4 years ago. Wish that you would do some troubleshooting videos. E G. Battery and solar charger and inverters. Awesome channel
you may have found the issue already... but here is an idea >>> you could use plastic stand-offs and plastic nonconductive screws then there would be no conduction between the BMS and the steel case... I bought a kit of plastic standoff for use with circuit boards vs the metal stand-offs... just an idea,,, it is always a potential issue if you want your system to be floating... you are certainly more expert than me ... but something to consider.... cheers from South Dakota
Andi, you can dip a neodymium magnet in a heat-shrinkable tube and then stick them on the battery cover of the multimeter. Thus the multimeter will "stick" to the Gobel case.
The display does not have touch. I have this for one of my two JK BMS. Looking forward to the solution on the dry contacts! Thanks for your work on all these!
The dry contact issue has been solved now and all new manufactured BMS will have this smaller resistor. You can swap it yourself and as soon as I have all the details, I'll make a video.
I purchased 4 Apexium DIY Box Kits with JK-Inverter-BMS (PB2A16S20P) (200A, 2A Active Balancer, Bluetooth, + 4.3 inch Touch Display). The BMS in the fist kit would not recognized cell 8 and 9. After swapping just the BMS everything worked. I did get it replaced but it took 6 months. In order to use the battery for the 6 months I used one of the two regular style JK-BMS (B2A24S20P) I had on the shelf, it worked perfectly and the 4.3 inch display worked too. By the way, this was not the fault of Apexium, they have the best kit I have every seen and will only get their Kit in the future.
At 20:23 Take a look at your -minus on the top of the bms. Is that lug touching the plate ? Do you still have contnuity after taking the cabels off the bms ?
Thanks Andy, your videos are very helpful and appreciated. I have 2 V15 JK BMS's myself with the latest firmware installed (downloaded from your site). I will do some groud testing tomorrow. Grouding is one of the most confusing topics for me. Maybe it is an idea to dedicate a video to that topic sometime in the future?
The weird balancing cable arrangement is caused by a configuration where some people use two separate 24 v batteries (A and B) in series, so one cable to cell nr 8 pos of battery A. And another cable to cell 9 neg. Of battery B . Since these batteries are connected by a jumper, the actual voltages of cable 8 and 9 are almost the same.
Got a V15 BMS with a faulty bluetooth module. Technical explanation: the BLE module received the "AT" command from the processor and responded with "OK" to the processor. Without this answer the BMS beeps several times during startup. So the receiving of data by the processor works. BLE module processor works. Antenna was faulty. Ordered BLE modules with external antenna, perfect when you build them into a metal case or cage of Faraday. Receive the modules next week. I'll keep you updated and mail some pictures of the work. Also replaced the relay resistors from 510 ohms with 240 ohm resistors.
The relay issue has been solved and all new BMS will have this smaller resistor to increase the voltage at the contactor. Does not help for existing BMS of course... Yeah, maybe send me some photos how to replace this resistor and I can make a video.
@claudetrichet2829 yeah, seems so. They just started to change their production so we won't see these new ones for a while. And we probably won't recognise them anyway.
Nice Video Andy. As many before me might notice there could be touch between those cables and heatsink Ofc once you removed them and use only one cable as it was intended it isn't clear if that voltage would be there as i believe you didn't do the test. Nonetheless it would be interesting to check that out. also that comment about heatsink touching some internal component could be valid idea.
Check for continuity on the 2nd bms while its on your bench, if the short from negative to ground has gone it was the way you fitted the battery negative cables to the bms as I mentioned earlier shorting the ring lug to the bms shielding
Sad to see what bad luck you had, i assembled 4 boxed out of 6 so far, without any issue, only trouble inhave is the cells ha e bouble screw terminals so i had to order new busbars. Other than that these boxes deserve some prais, that look and feel amazing 🙂
Hey Andy @OffGridGarageAustralia ! Thanks again for the video and a happy new year! 🎉 Great faultfind on the pictures in the Community tab! Could've been avoided from jks side with a coated or even non Aluminium heatshield/ -spreader or plastic sheeth like inserts around the BMS mounting screws wouldn't it? I wanted to ask you why exactly you keep your batterys floating w/o the negative grounded in your usecase? Commercial non diy batterys are often grounded in the negative when they are turned on iirc. Thanks for all the hard work and i hope you get some more amps outside this year! ☺️
@@aldente_ its real competition, PACE is far superior but not as many gimnics. PACE is also used on the pro marked, and has the right qualifications. JK lacks support in that department and is more or less a DIY product. PACE is more configurable front the display, th PC software is crappy though, but so is JK. Still i like the JK also...
4 years and zero hassle with my Seplos V2's, though they did have issues when they first brought them out, I'd give the manufacturers 3 months to iron out issues on new products.
Hey Andy. As Robert already pointed out, your own negative cables are the problem here. You have shorted ground to the aluminum cover of that BMS when you put two cables on one screw. Look closely at your negative cables.
I bought recently a 200A inverter BMS from Ali in hardware version 15A, software was 15.34. The plus connection is now without plug and socket, only crimpt wire M4 other side tinned conductor.
Hi Andy, quick update. JK also noticed the coil occasionally contacting the outer plate of the BMS. In the Yixiang box, it just so happened that a newer version of the BMS seems to be installed, with a bit of black insulating heatshrink around the coil. I wish I could upload the photo here, but that's not allowed. I'll e-mail it to you separately as proof :)
Hello Andi! You always recommend the JK BMS and it looks fabulous. However, for us in the United States, a very very popular. Inverter is the EG4 family, manufactured by luxpower A major pain in the ass is that the JK BMS does not support the eg4 or the luxpower CAN protocol. There seem to be some ways around it by using the now open source version of the Peter board but that is also a lot of work and messing around. If all you have is one battery ant one inverter like most of us do. Perhaps you would see it in your heart to use your connection with the JK folks to give them the very relevant feedback that users in the United States are not enjoying their product as much as they normally would, should they ever decide to support the EG4/luxpower CAN protocol right out of the box! At the very least, it would be a great service to your viewers if you did mention that in your videos when praising the glories of the JK BMS. It's wonderful out of the box if you use a victron inverter but not still good for us EG4 users 😢
I notice awhile ago that there is 2 different harnasses, one harness has cell 8 twice and the other has not got a 2nd cable coming out of the harness and you can see the gap in the plug connection, Also as I built my own cases, I always mount the BMS on nylon threaded post and also then on a 10mm perspex inner lid
Try stacking the negative terminals the other way around it looks like the one going to the right is in contact with the bms shielding. Also when you said that you were going through the bms settings you said LiFePO4 but the screen showed LTO, I would try the original bms now you have corrected the wiring
No, why would you change it if it runs perfectly for you... There is no need to upgrade. My first BD JK-BMS is also still going strong even having over 3yrs now on the clock. It just works.
Andy, your upper ring lug connection is visibly the case in minute 19:33 ff. I thought of that right at that moment where you connected earlier the two cables on this terminal. Please measure the continuity between that terminal and the schield of the BMS. By the way, I have a JK issue. The Bluetooth module is producing high RFI over the whole FM Broadcast up to the DAB Frequencies and Amateur Radio bands. They told me it is by design of that module. :-( Cheers Marc
@@OffGridGarageAustralia I have to accept that you are right. Watched it more times with looking closer. If the fault comes up only if it is turned on, I guess some contact of the MosFets to the case. Try to open and look at what MosFet contact peak to the case. But only my suggestion. Cheers Marc
@DG3ACM-Marc we have found the problem with the BMS. The coil of the current limiter touched the front panel of the BMS and made that connection. There are some photos in the Community tab of my channel. I also took a photo of the terminals so you can see the actual height.
@@OffGridGarageAustralia BÄM, you found it! I never had concerns that you will find the error. Well, I looked at the pictures, it is a really tight fit for the coil. Cheers Marc
I do agree with you to leave the batt negative floating. However, in the Victron documentation they always connect the batt neg to ground. I know, a home is not a boat or RV.
It's the two negative cables from the battery touching the heat sink.Haven't finished watching in case you got it. I thought of that as soon as you did it.
No it's not... if it was the case it would also happen when the bms is off. And Andy found the problem, it was something else (a known issue with a certain batch).
Andy, ich glaube, dass das 200A BMS nicht kaputt ist, sondern in einer Schutzfunktion hängen geblieben ist (kann mich auch irren) und das Zweite wurde durch die Verkabelung beschädigt. Teste bitte (auch wenn es viel Arbeit ist) das 200A BMS noch einmal mit der neuen Verkabelung.
I've done all this, the first BMS is toast. I'm working with Jikong to flash it again with new software but it is believed that it has a malfunction. The 'wrong' cabling does not damage the BMS. As shown, it does not show all cells but works just fine.
I am going to check my BMS now, I would also have like to have seen the multi meter reading between the negative output and the BMS case, would also be interested to see the covers off the case just in case they have left a long tail that wasn't trimmed touching the case
I suspect on of the insulating thermal mats has slipped during assembly somewhere and one of the MOSFETs is touching the case. That could explain, why the BMS needs to be on for this fault to occur.
Hi Andy - During the video I noticed the JK sense lead connector, second from the left at video time 3:38, appears to be separated from the motherboard. I was wondering if this is your culprit? I have two JK bms arriving tomorrow and am hoping it will all work out. Cheers from Montana! Love your content, Sir!
Es gibt übrigens von Tom Bötticher einen Batterie Essentials Kurs, in dem findet man richtig geile Details wie die Chemie sich verhält. zB bei Alterung und beim laden unter Null grad. Ich denke du würdest es auch so geil finden die Zellen in dieser Tiefe zu verstehen. Ich fand es jedenfalls toll.
Try Spacing the negative connection off on the BMS so it clears the Chassis You can probably do this using a thread with a lock nut to try it, I wouldn't recommend leaving it like that, but it may illustrate where the problem is.
I would like a BMS that checks for battery to ground resistance as often a low reading is a warning of something bad happening, would be nice to disconnect at that point.
@@OffGridGarageAustraliaEven though the posts are higher than the case, it still made me nervous of a short and I made sure my lugs didn’t overlap the case area. Incidentally, the ver15 , 1a, 100amp , has four posts for the cable lugs like the 200amp. It looks identical, just has less mosfets on the board. The problem is probably the coil shorting to the case as mentioned by another member. It doesn’t seem very well centred in the hole of the case and doesn’t have the heat shrink on the coil, like the 200amp you took out.
Need to get a Hipot tester to check your insulation to Gnd on all your wiring as you build. Myself on my DIY solar system for lighting protection I have solar panel negative attached to earth ground, all my cabinets are attached to earth ground for lighting protection. Therefore by design battery and cabinet negative is deliberately attached to earth ground at the MPPT side.
Danke für die vielen Infos zum JK BMS. Ich starte gerade mit dem Akku - Bau. Deine Videos helfen mir sehr. Weiter so. Es wäre toll , wenn du für deine deutschen Zuschauer auch Beiträge erstellen könntest. Gerade über die JK BMS (PB - Serie ) gibt's nicht wirklich viele Info's in deutscher Sprache. LG aus good old Germany.
I wonder if Mrs. Andy was walking by with a couple of SPATs, when you said “Alright come on, where’s the camera’s?” And is in the house calling the people with the white smocks?😊
Love your work mate 👌 that noark DC breaker you used for your battery bank, are they polarised? Does it matter which way you install the + and - cables if load is travelling both ways?
Hi Andy, I had a similar thing on my JK-BMS V15. And needed to do about the same trouble shooting as you did About 400mV between bms (battery case) and positive on the battery pack. And as in your case it started higher and dropped to this value as you described as a capacitor discharge. Designed and 3d printed a holder isolating the bms from the case and the voltage disappeared completely. I have two JK BMS 150A version and both are the same. So there could be something in the design maybe? Right now as it is so low voltage leak I will just run them in their isolating holder and be done with it. But I'm looking for an alternative BMS for the future. My BMS is from the batch with the coil problem and I have handled that as described by other posters but still this smal leak voltage...
I'm pretty interested to see how the warranty process goes for you Andy. If there's a warranty at all. I've just had 1 of these jkbms fail due to an inverter short circuit. 3 were in service at the time. Two survived with short circuit protection kicking in. One has blown at least one mosfet. was running 15.33 at the time. Guess there's a reason I bought 4 initially. Lets see a non youtubing pleb gets looked after. It was only 10 months since purchase. 😞
Did the fuse between the battery bank and the inverter not blow? It’s also suggested a class t fuse between the banks. As each BMS shut down, the current to the remaining BMS would have gotten larger and larger. Class T fuses may have saved the BMS. Though four class t fuses and holders (one for the inverter, three for the Battery banks) would cost more than the fried BMS. They should still be fused, and not dependant on the BMS to save the day.
@@RobSteve1 I run 125A DC breakers on each battery. none of them tripped. Inverter was not under load and there was very little charge current at the time. I would have expected the DC breaker to trip but they didn't. Thankfully two of the BMS's did their job successfully. Maybe I need another breaker or fuse to manage the paralleled banks to the inverter.
Hi Endy First of all, thank you for the work you do I wanted your opinion on the boxes that have lifepo4 batteries positioned vertically. I would like to buy the vertical box of the YixEnergy but I had heard that lifepo4 cells are better to keep horizontally, what do you think? Grazie
Yeah, I'm not a fan of having them installed horizontally. The manufacturers don't say anything about it but in all drawings, photos and graphics, they always show in an upright position.
Maybe the wrong wiring of balance cables was the issue why the V15 bms did not turn on? Maybe there is some differences from hardware V14 and F15. Hopefully you can check that too.
Maybe some 16S BMS have "split" balancing system 2x 8P, that why there is cable for 8 and 9 cell "ends" and then main - and +. Even JK 24S BMS you wire cell by cell and rest cabels you dont use, only main + from end. ANT BMS have strange way if you dont use all series from BMS you dont use some middle wires and you need connect 2 wires to one cell.
Just a question, have you retested since pulling the large wires off of the single stud. From angle shown wire lug could have been in contact with top chassis plate
Try linking a few in parallel. The software is also in a permanent state of beta. Try pace bms units and see the difference. I used jk units in the past and they are definitely an inferior unit.
Hello Andy, I have a B2A8S20P BMS with eight MB31 314A Lifepo4 batteries.. The Vendor ID: JK-B2A8S20P Serial No.: 407052C1643 Hardware Ver: V11A Software Ver: V11.54 Version: V4.30.0 If we connect using a mobile phone and the management software, PC-SOFTWARE-FOR-JKBMS-INVERTER-BMS ( latest version from jk website ), you can change most settings except under "Basic Settings" the "Calibrating current" can only only be 0 you cannot change it. If you change to 2 and try to ok it, it returns with a "Sending failure" error and does not update. "Charge and Discharge OTP" will not go below 61C (battery specs say 60C), do the same with "Sending failure". There are also a couple of other setting that cannot be modified or changed. Am I missing something important? Before starting I selected the "Lifepo4" defaults at the top of screen and modified those. Any assistance would be gratefully received. Regards, Ken.
Ken, I have a similar setup with 8 mb31. I had both the BMS like you have and a 200amp inverter BMS. I settled on the 200amp inverter BMS, as it had the relays that can be programmed to turn on a heater pad. I just booted up the B2A8s20P on the workbench and I see my settings are as Andy suggested, including the 60c. When changing parameters, you can’t always do them in the order they appear in the app. If a recovery setting is out of range of the protect setting, it will get this error. Make sure you set the over temp recovery first and then the over temp protect. In regard to the calibrating current, I cannot test without the BMS attached to a set of cells. There are not any great directions showing how to do this. Andy shows doing this in one of his videos, but it may have been for an inverter BMS. It involves using a power supply, setting it to a current and inputting the measured current into the calibration current setting. I don’t think it will accept a calibration current that is past a certain difference from what the BMS thinks it is calibrating.
Hallo Andy. Du bist dir sicher, dass nicht einfach die Kabelschuhe am Deckel des BMS anstehen und Kontakt haben ? Im Video (Minute 20:26) sieht es eventuell danach aus mfg
Random question I have 3 100ah 15cell rack mount batteries I’ve ordered a 330ah diy box I can’t add a battery to make the other 3 a 16cell ( welded bus bars :( no room) can I make the new battery a 15 cell can you do this with a JK BMS ?
Don't like the metal U-bar for the balance cables. Sharp edges in the punched-out holes, Tiny balance cables with thin insulation. ..? Once a short circuit and your balace cables go up in smoke. I have now fused all balance cables with a 2 Amp soldered fuse, gives me peace of mind...😊 . Alternative: use plastic U-channels on top.
Question that comes to my mind after watching this video is, what are the insulation specs of the jk BMS? Can this JK BMS be used for grid-connected systems? What with the DIY kit batteries and homologation of the system? Greetings Dirk
Is there a new feature in the 15.38 firmware that is not listed in the change Log? After your problem with the 100amp BMS, I decided to take out my spare v15 100amp and checked if the coil has the heat shrink insulation. It did. While I had it out I updated to 15.38 and the BMS only stays on for only 1 minute. It then shuts off. This is on the test bench without the battery sense leads connected. If I enable emergency, it stays on. This did not happen on the previous firmware builds. It is either a bug introduced in 15.38 or an undocumented change that shuts the BMS down when there are no battery sense leads reporting voltage or some other error related to not being installed.
This seems to be either a software bug or a new self test feature to shut down the BMS after one minute if not all the sense leads are connected. I force downgraded to 15.37 and had the same issue. It was only when I downgraded to 15.33 that the BMS would stay on when connected to power at the B- and positive in and with no balance leads connected. I was testing this on a 1a/100amp BMS. It could also be the 15.37 or 15.38 firmware causes a bug with the smaller BMS.
This cabling identification problen is not that uncommon through the electrical industry, I see it occasionally. Also metal casings of equipment having continuity to earth is more and more common due to faulty electronic components, shows up with low voltages and RCDs tripping out. Always test stuff before you energise...stay safe and keep the magic smoke in the lamp😅
Of the six JK-BMS I bought last summer, three had to go in the trash because they were poorly built or contained defective components. A 50% product failure rate is just not acceptable.
Hey Andy, Merry xmas / new year.
Check for contact between the current limiting coil and the BMS front plate, I found several of a particular batch that had contact between the winding that returned to the PCB and it causes this issue, you will notice the later generation has heatshrink covering the coil totally, ive also seen what can happen if this is not caught before commisioning.
You can gently pry this coil away and heatshrink.
Also, this wiring issue / arrangement of balance cables has never been apparent on any batches we have purchased for the business 🤔
@OffGridGarageAustralia
@@nzlithium1352 confirmed! The winding of the coil was indeed touching the front panel. I pushed it away and rearranged the coil a bit and problem solved!
I'll talk to Jikong if they can make this round cutout a bit wider.
Thank you.
@@OffGridGarageAustralia likely no need, if you take a look at your other one with heatshrink over the coil, they realized the problem and solved it, albeit there will be several BMS with this issue in commision, and it can be a nasty outcome in the right situation. . .
I've posted some pictures here: www.youtube.com/@OffGridGarageAustralia/community
@@OffGridGarageAustraliaAnd the comments that it's your cables just keep on rolling in 😂😂🤦🏻
A few weeks ago, I stumbled on one of your video while looking for a review on a bms. I got attracted by your german accent (Es gab eine Zeit, in der ich Deutsch sprach) and I have learned a lot through your videos. I finally orderded a V15 JK inverter bms that I just tested yesterday. Working on a self consumption system using grid as partial storage (injection tarrif are good here) to lower battery volume. So far so good, integration with both victron (cerbo gx) and sma sunny island is underway thanks to your very informative contents. Thanks again from Dakar , Sénégal, and keep it up.
Yes, I also think that is the Problem. If you look in the Video (at 20:14), than you can see the ring lug on the minus touching the cover of the bms.
Sunny greetings from Austria! Robert
Saw that too - Andy: do you still have continuity after taking the BMS out?
I think you are on to something. It's usually the simplest thing.
saw the same thing, good of you to mention it.
On the second BMS install I think he swapped the order around so the one closer to the terminal was coming from the side with greater clearance.
I was going to say the same thing. I think this is self inflicted. Congratulations go to him for spotting the problem when he got that tingle and not just ignoring it. That’s a good lesson for the young ones to learn. If you see/feel/smell something not right, stop and make sure you fully understand or correct the problem before continuing on.
Thank you for your hard work to help all of us !!!! 🙏🙏
Lucky escape. Glad you got the mild tingly warning. Someone up there loves you bro. Keep up the good work 👊🏾🙏🏾
Hello Andy
Thanx for all your inspiring video's.
Just some info regarding the coil theme:
I looks like the 100A V15 models are at least in two ways different from your V14 model.
1 - the (current limiting) coil is already wrapped in heatshrink
2 - there are 4 screw terminals instead of 2.
Good fault finding, and learned something new! Your videos are always great.
Looking forward to seeing the seplos v4 bms test video here, giving everyone a clear direction
Hi Andy,
I think the reason for the cell wiring is when you sepperate the battery in two there is a cable between cell 8 and cell 9 and no bussbar. And now you can still measure de cells and dont measure the voltage drop of the connecting cable.
Keep up the good work Andy!👍🏼
Yes, that was with the older style battery where we had a fuse between bat8 and bat9. Hence they uses an additional balance cable for a 'fake' negative in case the fuse tripped to have 2x 24V batteries with a 'main negative' each.
In the last video I wrote that Gobel boxing is not the best. But after watching this video - THESE ARE THE WORST cases that exist. Thanks Andy for your work.
Nope they are the best, but Andy make mistakes.
I am using EEL since version 1, ordered V5 to be delivered end of Jan. Quality just perfect
I love both of my Gobel boxes. I had none of the problems that Andy has had and I fully recommend Gobel. Their MB31 cells are excellent. I trusted Gobel enough that I wired the money to them instead of using a credit card, knowing that if anything went wrong, I would have no recourse. I was not disappointed.
The ring lug on the minus coming from the battery is very close to the heatsink and if it has connection the heatsink becomes minus and then the screw holding the bms is touching the heatsink and then the case becomes minus potential.
No, it is not very close. If you have a JK, look for yourself.
@@OffGridGarageAustralia It looks like the lug of the wire to the right may be touching the heat shield. Try with the lug pointing up instead of to the right and I bet the issue goes away.
@@OffGridGarageAustralia i agree with what he said. It may look different to you, but in the video the lug looks like its giving the heatshield an intimate massage. We cant see as well as you can since were not there, but do take a closer look at it.
Edit: see 20:43 left lug is fine, right looks questionable.
@@OffGridGarageAustraliaOf course it's touching the plate....!
Hi Andy.
Loved the video as usual, but I have to point out what many have already pointed out. The right lug coming off of the BMS negative is touching the the BMS case. If you were to put the right lug on top of the left lug instead of the way it is in the video (right lug under left lug) this would raise the lug up and away from the BMS case.
I have also read your responses in that you say this is not the fault. I work on domestic appliances and sometimes the obvious may not seem obvious at the time and as we get frustrated we talk ourselves into believing the module is faulty when it is not. In my experience the chances of having 2 faulty modules one after the other like that is almost impossible odds. I suspect both BMS's are ok. The first one because of the issue with the balance cables issues (plus it has a completely different firmware version which could affect the outcome) and the second one because of the negative lug touching the BMS casing.
I know it takes time but I would reconnect your original BMS now that the balance cables are rectified and see it it works normally and I would also reconnect the second BMS and watch you video back and attach the negative cables exactly the same and test the following
- Between the battery negative and the BMS case you would have continuity (possible faulty BMS or something touching somewhere).
or
- Disconnect negative lug from the BMS and measure continuity when the between negative terminal on the BMS to the BMS case. (If there is no continuity then it's NOT a faulty BMS, if there is continuity then it IS as faulty BMS).
He found the issue and it was not that.
If this was the case he would see a contact also when the BMS is off, which was not the case.
Thank you Andy, excellent deductive problem finding tutorial. Keep it up!
Thanks Andy, 👍👍👍👍
Good stuff as usual! Cheers
Thank you again for a great video.
Just think of the pain one would go through if they had to wait for a new BMS to be shipped out each time, all that while still needing power for their OFF GRID system, remember some of us have NO GRID.
Hey man great video. I have a small system that I built watching your video 3-4 years ago. Wish that you would do some troubleshooting videos. E G. Battery and solar charger and inverters.
Awesome channel
Yeah, I don't have any EG equipment. And no troubleshooting without fault...
you may have found the issue already... but here is an idea >>> you could use plastic stand-offs and plastic nonconductive screws then there would be no conduction between the BMS and the steel case... I bought a kit of plastic standoff for use with circuit boards vs the metal stand-offs... just an idea,,, it is always a potential issue if you want your system to be floating... you are certainly more expert than me ... but something to consider.... cheers from South Dakota
The double ringlug is touching the BMS housing, have you checked the faulty bms on the work bench?
As seen at 20:00
Nope, that's not the problem and would be solid connection. As you may have seen in the video, the fault only occurs when the BMS is turned on.
@@OffGridGarageAustralia When the BMS is turned on the P- and B- is connected. Maby this is the problem?
Andi, you can dip a neodymium magnet in a heat-shrinkable tube and then stick them on the battery cover of the multimeter.
Thus the multimeter will "stick" to the Gobel case.
The display does not have touch. I have this for one of my two JK BMS. Looking forward to the solution on the dry contacts! Thanks for your work on all these!
The dry contact issue has been solved now and all new manufactured BMS will have this smaller resistor. You can swap it yourself and as soon as I have all the details, I'll make a video.
@@OffGridGarageAustralia So its a hardware issue?
@@darrenorange2982 Yes, it is. The relay does not get enough voltage as one resistor was designed with a too high value. This can be replaced though.
the minus cable was touching the bms housing, now check if there is a short circuit to minus
Nope, that's not the problem and would be solid connection. As you may have seen in the video, the fault only occurs when the BMS is turned on.
Andy, look at the negative cable lug,position. . It look's like you are connecting the terminal and touching the bms case at the same time.
Nope, that's not the problem and would be solid connection. As you may have seen in the video, the fault only occurs when the BMS is turned on.
I purchased 4 Apexium DIY Box Kits with JK-Inverter-BMS (PB2A16S20P) (200A, 2A Active Balancer, Bluetooth, + 4.3 inch Touch Display). The BMS in the fist kit would not recognized cell 8 and 9. After swapping just the BMS everything worked. I did get it replaced but it took 6 months. In order to use the battery for the 6 months I used one of the two regular style JK-BMS (B2A24S20P) I had on the shelf, it worked perfectly and the 4.3 inch display worked too. By the way, this was not the fault of Apexium, they have the best kit I have every seen and will only get their Kit in the future.
At 20:23 Take a look at your -minus on the top of the bms. Is that lug touching the plate ? Do you still have contnuity after taking the cabels off the bms ?
Nope, that's not the problem and would be solid connection. As you may have seen in the video, the fault only occurs when the BMS is turned on.
Complimenti da quando abbiamo la traccia audio in italiano è un piacere guardare i tuoi video! Grazie!
Thanks Andy, your videos are very helpful and appreciated. I have 2 V15 JK BMS's myself with the latest firmware installed (downloaded from your site). I will do some groud testing tomorrow. Grouding is one of the most confusing topics for me. Maybe it is an idea to dedicate a video to that topic sometime in the future?
The weird balancing cable arrangement is caused by a configuration where some people use two separate 24 v batteries (A and B) in series, so one cable to cell nr 8 pos of battery A. And another cable to cell 9 neg. Of battery B . Since these batteries are connected by a jumper, the actual voltages of cable 8 and 9 are almost the same.
There was also a time when Gobel and others installed a fuse between bat 8 and 9. If this goes off, you basically have 2x separate 24V batteries.
Got a V15 BMS with a faulty bluetooth module. Technical explanation: the BLE module received the "AT" command from the processor and responded with "OK" to the processor. Without this answer the BMS beeps several times during startup. So the receiving of data by the processor works. BLE module processor works. Antenna was faulty. Ordered BLE modules with external antenna, perfect when you build them into a metal case or cage of Faraday. Receive the modules next week. I'll keep you updated and mail some pictures of the work. Also replaced the relay resistors from 510 ohms with 240 ohm resistors.
The relay issue has been solved and all new BMS will have this smaller resistor to increase the voltage at the contactor. Does not help for existing BMS of course...
Yeah, maybe send me some photos how to replace this resistor and I can make a video.
I don't know that for sure Andy, these are bought dec 2024 and still had the 510 ohm redistor on them. Maybe an older batch?
@claudetrichet2829 yeah, seems so. They just started to change their production so we won't see these new ones for a while.
And we probably won't recognise them anyway.
I still like the Daly BMS - my 200A runs like a charm
Nice Video Andy. As many before me might notice there could be touch between those cables and heatsink Ofc once you removed them and use only one cable as it was intended it isn't clear if that voltage would be there as i believe you didn't do the test.
Nonetheless it would be interesting to check that out. also that comment about heatsink touching some internal component could be valid idea.
Check for continuity on the 2nd bms while its on your bench, if the short from negative to ground has gone it was the way you fitted the battery negative cables to the bms as I mentioned earlier shorting the ring lug to the bms shielding
Nope, that's not the problem and would be solid connection. As you may have seen in the video, the fault only occurs when the BMS is turned on.
Sad to see what bad luck you had, i assembled 4 boxed out of 6 so far, without any issue, only trouble inhave is the cells ha e bouble screw terminals so i had to order new busbars. Other than that these boxes deserve some prais, that look and feel amazing 🙂
Thats right!
Hey Andy @OffGridGarageAustralia ! Thanks again for the video and a happy new year! 🎉
Great faultfind on the pictures in the Community tab! Could've been avoided from jks side with a coated or even non Aluminium heatshield/ -spreader or plastic sheeth like inserts around the BMS mounting screws wouldn't it?
I wanted to ask you why exactly you keep your batterys floating w/o the negative grounded in your usecase? Commercial non diy batterys are often grounded in the negative when they are turned on iirc. Thanks for all the hard work and i hope you get some more amps outside this year! ☺️
We desperately need competition for JKBMS.
The cable lug is the problem.... not the bms
You have, pace!
@@jelleklinge9743 Real competition, not any competition.
@@aldente_ its real competition, PACE is far superior but not as many gimnics. PACE is also used on the pro marked, and has the right qualifications. JK lacks support in that department and is more or less a DIY product. PACE is more configurable front the display, th PC software is crappy though, but so is JK. Still i like the JK also...
Something Made in Europe, opensource.
4 years and zero hassle with my Seplos V2's, though they did have issues when they first brought them out, I'd give the manufacturers 3 months to iron out issues on new products.
Hey Andy. As Robert already pointed out, your own negative cables are the problem here. You have shorted ground to the aluminum cover of that BMS when you put two cables on one screw. Look closely at your negative cables.
Very cool Video, cool greetings from Austria
That's why i use edge cover sleeve on BMS shields and direct terminal outside while screwing.
Atleast your BMS’s are creating content for you :):):)
Came here to say that the negative battery lug is probably the culprit, seems I wasn't the first one to see it
Nope, that's not the problem and would be solid connection. As you may have seen in the video, the fault only occurs when the BMS is turned on.
I bought recently a 200A inverter BMS from Ali in hardware version 15A, software was 15.34. The plus connection is now without plug and socket, only crimpt wire M4 other side tinned conductor.
Hi Andy, quick update. JK also noticed the coil occasionally contacting the outer plate of the BMS. In the Yixiang box, it just so happened that a newer version of the BMS seems to be installed, with a bit of black insulating heatshrink around the coil. I wish I could upload the photo here, but that's not allowed. I'll e-mail it to you separately as proof :)
Hello Andi!
You always recommend the JK BMS and it looks fabulous. However, for us in the United States, a very very popular. Inverter is the EG4 family, manufactured by luxpower
A major pain in the ass is that the JK BMS does not support the eg4 or the luxpower CAN protocol. There seem to be some ways around it by using the now open source version of the Peter board but that is also a lot of work and messing around. If all you have is one battery ant one inverter like most of us do.
Perhaps you would see it in your heart to use your connection with the JK folks to give them the very relevant feedback that users in the United States are not enjoying their product as much as they normally would, should they ever decide to support the EG4/luxpower CAN protocol right out of the box!
At the very least, it would be a great service to your viewers if you did mention that in your videos when praising the glories of the JK BMS. It's wonderful out of the box if you use a victron inverter but not still good for us EG4 users 😢
I'll pass this on to Jikong...
@@OffGridGarageAustralia Thank you! and Fingers crossed! :-)
The negative cable Lug was touching the back plate of the BMS. You can see it.
I notice awhile ago that there is 2 different harnasses, one harness has cell 8 twice and the other has not got a 2nd cable coming out of the harness and you can see the gap in the plug connection, Also as I built my own cases, I always mount the BMS on nylon threaded post and also then on a 10mm perspex inner lid
Try stacking the negative terminals the other way around it looks like the one going to the right is in contact with the bms shielding.
Also when you said that you were going through the bms settings you said LiFePO4 but the screen showed LTO, I would try the original bms now you have corrected the wiring
I'm over 100kWh now on my custom battery shelf with original JK BMS without a single issue. Not going to change that any time soon...
No, why would you change it if it runs perfectly for you... There is no need to upgrade. My first BD JK-BMS is also still going strong even having over 3yrs now on the clock. It just works.
Just followed the directions, measured voltages on the connectors before installing to the JK BMS on my ~250kWh of diy batteries.
Thanks Andy
Andy, your upper ring lug connection is visibly the case in minute 19:33 ff.
I thought of that right at that moment where you connected earlier the two cables on this terminal.
Please measure the continuity between that terminal and the schield of the BMS.
By the way, I have a JK issue. The Bluetooth module is producing high RFI over the whole FM Broadcast up to the DAB Frequencies and Amateur Radio bands.
They told me it is by design of that module. :-(
Cheers
Marc
Nope, that's not the problem and would be solid connection. As you may have seen in the video, the fault only occurs when the BMS is turned on.
@@OffGridGarageAustralia I have to accept that you are right. Watched it more times with looking closer.
If the fault comes up only if it is turned on, I guess some contact of the MosFets to the case. Try to open and look at what MosFet contact peak to the case.
But only my suggestion.
Cheers
Marc
@DG3ACM-Marc we have found the problem with the BMS. The coil of the current limiter touched the front panel of the BMS and made that connection. There are some photos in the Community tab of my channel. I also took a photo of the terminals so you can see the actual height.
@@OffGridGarageAustralia BÄM, you found it! I never had concerns that you will find the error. Well, I looked at the pictures, it is a really tight fit for the coil.
Cheers
Marc
Hello Andy,
it looks like you shoted B- to the BMSes case.
Please check your B- wiring and the screw terminal.
Nope, that's not the problem and would be solid connection. As you may have seen in the video, the fault only occurs when the BMS is turned on.
I do agree with you to leave the batt negative floating. However, in the Victron documentation they always connect the batt neg to ground. I know, a home is not a boat or RV.
I never did that and always floated my batteries.
It's the two negative cables from the battery touching the heat sink.Haven't finished watching in case you got it. I thought of that as soon as you did it.
No it's not... if it was the case it would also happen when the bms is off.
And Andy found the problem, it was something else (a known issue with a certain batch).
Andy, ich glaube, dass das 200A BMS nicht kaputt ist, sondern in einer Schutzfunktion hängen geblieben ist (kann mich auch irren) und das Zweite wurde durch die Verkabelung beschädigt.
Teste bitte (auch wenn es viel Arbeit ist) das 200A BMS noch einmal mit der neuen Verkabelung.
I've done all this, the first BMS is toast. I'm working with Jikong to flash it again with new software but it is believed that it has a malfunction.
The 'wrong' cabling does not damage the BMS. As shown, it does not show all cells but works just fine.
I am going to check my BMS now, I would also have like to have seen the multi meter reading between the negative output and the BMS case, would also be interested to see the covers off the case just in case they have left a long tail that wasn't trimmed touching the case
I suspect on of the insulating thermal mats has slipped during assembly somewhere and one of the MOSFETs is touching the case. That could explain, why the BMS needs to be on for this fault to occur.
Hi Andy - During the video I noticed the JK sense lead connector, second from the left at video time 3:38, appears to be separated from the motherboard. I was wondering if this is your culprit? I have two JK bms arriving tomorrow and am hoping it will all work out. Cheers from Montana! Love your content, Sir!
I read the other comments to the solution - thanks
Es gibt übrigens von Tom Bötticher einen Batterie Essentials Kurs, in dem findet man richtig geile Details wie die Chemie sich verhält. zB bei Alterung und beim laden unter Null grad. Ich denke du würdest es auch so geil finden die Zellen in dieser Tiefe zu verstehen. Ich fand es jedenfalls toll.
Sneaky Andy 2 was at it again
Try Spacing the negative connection off on the BMS so it clears the Chassis You can probably do this using a thread with a lock nut to try it, I wouldn't recommend leaving it like that, but it may illustrate where the problem is.
That is not the problem. The terminals of the BMS are higher than the panels.
I would like a BMS that checks for battery to ground resistance as often a low reading is a warning of something bad happening, would be nice to disconnect at that point.
My first BMS was as complicated to install but I got it working the first attempt...
The posts for the battery cable lugs on the BMS are higher than the case of the BMS and it is probably not the problem.
Exactly, so many people are just getting it wrong here.
@@OffGridGarageAustraliaEven though the posts are higher than the case, it still made me nervous of a short and I made sure my lugs didn’t overlap the case area. Incidentally, the ver15 , 1a, 100amp , has four posts for the cable lugs like the 200amp. It looks identical, just has less mosfets on the board.
The problem is probably the coil shorting to the case as mentioned by another member. It doesn’t seem very well centred in the hole of the case and doesn’t have the heat shrink on the coil, like the 200amp you took out.
Need to get a Hipot tester to check your insulation to Gnd on all your wiring as you build.
Myself on my DIY solar system for lighting protection I have solar panel negative attached to earth ground, all my cabinets are attached to earth ground for lighting protection. Therefore by design battery and cabinet negative is deliberately attached to earth ground at the MPPT side.
@7:20 31f? Don't charge that thing! I didn't know Australia got that cold in the Summer...
😂😂😂
Danke für die vielen Infos zum JK BMS.
Ich starte gerade mit dem Akku - Bau.
Deine Videos helfen mir sehr.
Weiter so.
Es wäre toll , wenn du für deine deutschen Zuschauer auch Beiträge erstellen könntest.
Gerade über die JK BMS
(PB - Serie ) gibt's nicht wirklich viele Info's in deutscher Sprache.
LG aus good old Germany.
It looks like the cable lug of the negative connection point touches the aluminum top plate of the BMS
I saw that also. It's the cable lug. It is not your bms!
No, that's just how it looks like on camera. Have a look at your JK how much space there is.
@@OffGridGarageAustralia can you explain why there is no continuty when the cable lug is disconnected?
@@marrekau117 Yes.
Hello Andi!
Where can I find busbars like you have with the built in screw thread for the balance leads?
Hallo Andy, do you know if JK BMS works with the new Solis LV Hybrid Inverters?
Love it how you peel down the onion. Nice video :) Silly question, but what is the type/name of the small red plug you connected to the bms cable?
No idea, it is just a single cable connector. I have not see it as a separate part anywhere. I'm sure you can find a similar connector on AliExpress.
Hi, Andy are you grounding to the case, ie neg
WTF, not a could start. But good fault finding
I wonder if Mrs. Andy was walking by with a couple of SPATs, when you said “Alright come on, where’s the camera’s?” And is in the house calling the people with the white smocks?😊
Love your work mate 👌 that noark DC breaker you used for your battery bank, are they polarised? Does it matter which way you install the + and - cables if load is travelling both ways?
The Noarks are not polarised. That would make them unsuitable for most solar and battery designs.
@OffGridGarageAustralia thanks mate 👍 love your work
Hi Andy, I had a similar thing on my JK-BMS V15. And needed to do about the same trouble shooting as you did
About 400mV between bms (battery case) and positive on the battery pack. And as in your case it started higher and dropped to this value as you described as a capacitor discharge. Designed and 3d printed a holder isolating the bms from the case and the voltage disappeared completely.
I have two JK BMS 150A version and both are the same. So there could be something in the design maybe? Right now as it is so low voltage leak I will just run them in their isolating holder and be done with it. But I'm looking for an alternative BMS for the future.
My BMS is from the batch with the coil problem and I have handled that as described by other posters but still this smal leak voltage...
Did the Same with my Version 15. With three D Print on (pla) petg Basis in White..👍☺️(Typo in First Post)
@@Carsten-PV-DIY I used ABS FR to handle heat better...
@@tx75e94 Sorry, Typo I meant petg. 🫣😇
I'm pretty interested to see how the warranty process goes for you Andy. If there's a warranty at all.
I've just had 1 of these jkbms fail due to an inverter short circuit. 3 were in service at the time. Two survived with short circuit protection kicking in. One has blown at least one mosfet. was running 15.33 at the time.
Guess there's a reason I bought 4 initially. Lets see a non youtubing pleb gets looked after. It was only 10 months since purchase. 😞
Did the fuse between the battery bank and the inverter not blow? It’s also suggested a class t fuse between the banks. As each BMS shut down, the current to the remaining BMS would have gotten larger and larger. Class T fuses may have saved the BMS. Though four class t fuses and holders (one for the inverter, three for the Battery banks) would cost more than the fried BMS. They should still be fused, and not dependant on the BMS to save the day.
@@RobSteve1 I run 125A DC breakers on each battery. none of them tripped. Inverter was not under load and there was very little charge current at the time. I would have expected the DC breaker to trip but they didn't. Thankfully two of the BMS's did their job successfully. Maybe I need another breaker or fuse to manage the paralleled banks to the inverter.
You need a fuse, what ever size your inverter manual suggests, between the inverter and the battery.
What's the best charging voltage per cell for longevity?
Hi Endy
First of all, thank you for the work you do
I wanted your opinion on the boxes that have lifepo4 batteries positioned vertically.
I would like to buy the vertical box of the YixEnergy
but I had heard that lifepo4 cells are better to keep horizontally, what do you think?
Grazie
Yeah, I'm not a fan of having them installed horizontally. The manufacturers don't say anything about it but in all drawings, photos and graphics, they always show in an upright position.
Heya, good that JK has a good retourn policy
Have they?
Maybe the wrong wiring of balance cables was the issue why the V15 bms did not turn on? Maybe there is some differences from hardware V14 and F15. Hopefully you can check that too.
Maybe some 16S BMS have "split" balancing system 2x 8P, that why there is cable for 8 and 9 cell "ends" and then main - and +.
Even JK 24S BMS you wire cell by cell and rest cabels you dont use, only main + from end.
ANT BMS have strange way if you dont use all series from BMS you dont use some middle wires and you need connect 2 wires to one cell.
I'm still using my same four Daly's
You are right. Badly prépare, badly cabled
Just a question, have you retested since pulling the large wires off of the single stud. From angle shown wire lug could have been in contact with top chassis plate
Nope, that's not the problem and would be solid connection. As you may have seen in the video, the fault only occurs when the BMS is turned on.
Try linking a few in parallel. The software is also in a permanent state of beta. Try pace bms units and see the difference. I used jk units in the past and they are definitely an inferior unit.
Pace software is so far behind... keeps the battery on high SOC and voltage once fully charged.
If you don't innovate, you can't make mistakes😊
Why are you touching the 48V @3:08 ? How did it feel?
It's just a tingle.
Hello Andy,
I have a B2A8S20P BMS with eight MB31 314A Lifepo4 batteries..
The Vendor ID: JK-B2A8S20P
Serial No.: 407052C1643
Hardware Ver: V11A
Software Ver: V11.54
Version: V4.30.0
If we connect using a mobile phone and the management software, PC-SOFTWARE-FOR-JKBMS-INVERTER-BMS ( latest version from jk website ),
you can change most settings except under "Basic Settings" the "Calibrating current" can only only be 0 you cannot change it.
If you change to 2 and try to ok it, it returns with a "Sending failure" error and does not update.
"Charge and Discharge OTP" will not go below 61C (battery specs say 60C), do the same with "Sending failure".
There are also a couple of other setting that cannot be modified or changed.
Am I missing something important? Before starting I selected the "Lifepo4" defaults at the top of screen and modified those.
Any assistance would be gratefully received.
Regards,
Ken.
Ken, I have a similar setup with 8 mb31. I had both the BMS like you have and a 200amp inverter BMS. I settled on the 200amp inverter BMS, as it had the relays that can be programmed to turn on a heater pad. I just booted up the B2A8s20P on the workbench and I see my settings are as Andy suggested, including the 60c.
When changing parameters, you can’t always do them in the order they appear in the app. If a recovery setting is out of range of the protect setting, it will get this error. Make sure you set the over temp recovery first and then the over temp protect.
In regard to the calibrating current, I cannot test without the BMS attached to a set of cells. There are not any great directions showing how to do this. Andy shows doing this in one of his videos, but it may have been for an inverter BMS. It involves using a power supply, setting it to a current and inputting the measured current into the calibration current setting. I don’t think it will accept a calibration current that is past a certain difference from what the BMS thinks it is calibrating.
Was not the negative cable with right lug touching the carcass of second bms?
No, that is impossible. Also would not explain why the BMS need to be on to have this fault.
Thank you, Andy. You are the man. Carlos, from Brazil.
Hallo Andy. Du bist dir sicher, dass nicht einfach die Kabelschuhe am Deckel des BMS anstehen und Kontakt haben ? Im Video (Minute 20:26) sieht es eventuell danach aus mfg
Random question I have 3 100ah 15cell rack mount batteries I’ve ordered a 330ah diy box I can’t add a battery to make the other 3 a 16cell ( welded bus bars :( no room) can I make the new battery a 15 cell can you do this with a JK BMS ?
Don't like the metal U-bar for the balance cables. Sharp edges in the punched-out holes, Tiny balance cables with thin insulation. ..? Once a short circuit and your balace cables go up in smoke. I have now fused all balance cables with a 2 Amp soldered fuse, gives me peace of mind...😊 . Alternative: use plastic U-channels on top.
Question that comes to my mind after watching this video is, what are the insulation specs of the jk BMS? Can this JK BMS be used for grid-connected systems? What with the DIY kit batteries and homologation of the system? Greetings Dirk
No idea, ask JIKONG for documentation.
Probably now other BMS will work properly... when all wires are on the right terminal's...?
Did you check that?
But after the issue did the monitor do anything deferent? 102K Congrats Andy.
Still the same. It seems to be a single screen display only.
Is there a new feature in the 15.38 firmware that is not listed in the change Log? After your problem with the 100amp BMS, I decided to take out my spare v15 100amp and checked if the coil has the heat shrink insulation. It did. While I had it out I updated to 15.38 and the BMS only stays on for only 1 minute. It then shuts off. This is on the test bench without the battery sense leads connected. If I enable emergency, it stays on. This did not happen on the previous firmware builds. It is either a bug introduced in 15.38 or an undocumented change that shuts the BMS down when there are no battery sense leads reporting voltage or some other error related to not being installed.
This seems to be either a software bug or a new self test feature to shut down the BMS after one minute if not all the sense leads are connected. I force downgraded to 15.37 and had the same issue. It was only when I downgraded to 15.33 that the BMS would stay on when connected to power at the B- and positive in and with no balance leads connected. I was testing this on a 1a/100amp BMS. It could also be the 15.37 or 15.38 firmware causes a bug with the smaller BMS.
This cabling identification problen is not that uncommon through the electrical industry, I see it occasionally. Also metal casings of equipment having continuity to earth is more and more common due to faulty electronic components, shows up with low voltages and RCDs tripping out.
Always test stuff before you energise...stay safe and keep the magic smoke in the lamp😅
Of the six JK-BMS I bought last summer, three had to go in the trash because they were poorly built or contained defective components. A 50% product failure rate is just not acceptable.
Hi guys. After updating the BMS to the latest firmware (15.37), i have a problem - the SOC does not rise to 100%, only to 99%. How to fix it?
I’m getting a feeling that Andy is never going to find an acceptable BMS.
Hahaha, yeah, we will get there eventually.
Maybe we should run without BMS as some have suggested in the past and do bottom balancing😬
siehst du nicht das du den Massekurzschluss über den Ringkabelschuh auf die Alu Platte machst ?
Das mach er nicht...
Thats why we are working with 48V instead of High voltage.