I opened one (the 100A version) up and posted pictures on the DIY site, including a link to the MOSFET datasheet etc. Long story short: you don't need to down-rate the BMS; the design is not pushing the MOSFETS and has a safety margin by design.
Thank you, J. Links are here diysolarforum.com/threads/bms-mosfets-explained.29318/ and diysolarforum.com/threads/jbd-overkill-vs-jk-heltec-bms.29309/post-352783
Definitely good to know that they’re designed for 100% rated operation. Still it doesn’t hurt to derate them a little bit to give it some headroom. From experience, it is less stress on the MOSFETs.
@@OffGridGarageAustralia Für saubere DC Spannung,gehst du da direkt auf den Block und greifst die 48 Volt ab? Ich hab ein bisschen bedenken mir ein JK zuzulegen wegen der Mosfets und der Fehlfunktion(Jumping up and down ruclips.net/video/edvKvxFpkec/видео.html) wann man viel Amps über das BMS abggreift. Das ist doch eine getaktete Spannung? sowie ich das sehe und bei starker Last bricht das Bms ein bisschen zusammen , das finde ich ein wenig risikoreich. Ist da das Relais BMS nicht besser? klar geht der aktive balancer ab aber gibt es ja zu kaufen , jetzt nicht die die du schon gezeigt hast gibt andere... sind hald sehr teuer Wie alt werden solche BMS?
@@BavarianSuperGuy Sind halt halbleiterprodukte. Scheint aber sehr robust zu sein. Kann also schon sehr alt werden. Wo bricht das BMS ein? Die Spannung geht bei der Last runter, das hat aber mehr mit dem Innenwiderstand der Batterie zu tun. So ein Relais zieht Dauerhaft Strom (oder sind das bistabile?) da ist dies hier schon deutlich effizienter.
The BMS' current reporting jumps up and down by 10% probably because its averaging period is too short to smooth out the current ripples from the inverter's 50Hz output, so it reads different current depending on what point of the AC sine wave the inverter is at. Keep in mind that the instantaneous peak power of a resistive AC load is double the RMS value, so the inverter's output stage is pulling nearly 100A from its internal capacitors, your BMS is seeing the leftover ripples.
Good morning Andy from Italy. I discovered your channel and I want to congratulate you because it is very funny and technically perfect. I already have a JK BMS in a battery pack in my RV, home built. I also tested how the internal balancer works. I did it by charging the batteries with a 30A charger. The balancer works fine up to a certain point, then loses working capacity when you are over 90% charged or under 10% (2A vs 30A are not enough, i think). The gap has risen above 100mV. Maybe my battreies aren't that good.. I'll keep within those limits Thanks and good job
Super test !!! Top batteries !!! I like this video very much. I think you spend a lot of time editing this 40:55min video. Good work ! 👏 I appreciate !
Thank you very much Alex. I really appreciate you appreciate the videos and effort. The whole editing part is killing me. Timewise... This one took like 7h 🤦♂️ Not many people see all the work behind that. So thank you again!
Pretty dang good correlation among a bunch of el cheapo measuring devices that are not even calibrated. Your kluged up system is working very well in a real world environment.
After a bit more then a year I've started to have issues with my Daly bms, the balancing is so far out now that the daly just can't keep up and is shutting the charging mosfet at 85% SOC. Just purchased two of these jk bms's to help solve this issue. thanks for the video and amazing testing, back to trickle charging my cells in hopes the daly can balance some of this issue back out while the jk's are in the mail. Used your links hope you get some kick back!!
Dear Andy, First of all thank you very much for these very good and clear video's. It really helped me a lot. I bought the JK BMS and I want to use it for my battery pack 15S3P with EVE cells of each 280Ah. The balancing functioning is crucial for these large batteries I think. Actually you convenced me :). Now a friend told me that the JK BMS is not suitable to handle parallel cells. Now I do not know what to do anymore. Can you please try to clear this up. I can't understand why a JK BMS can not handle the three parallel cells. He also told that a Daly BMS can handle the 3 parallel cells. Kind regards Wouter Swart from the Netherlands
This is such compelling battery testing with instructions and information about so many details. Thank you so much Andy. I took the plunge and started buying components and tools. Battery (24v, 280ah Saben eve) should arrive in a month or so. But...i am still searching online to buy a bit of that perfect ambient temp for my offgrid cabin situated in north Europe.
Thanks for the education that you provide with your videos. Thanks to you I’m in the next couple months going to buy (through your links) 50 304 amp hour batteries and three BMS. Going to build 3 48 volt packs with 2 extra batteries (just in case). Looking forward to your shelf build because that’s what I’m building. Again thank you very much
Great show again Andy. I want one!! Hang on I said that when you tested the first lot of EVE cells, so I got 12v worth. I couldn't be happier. Yes integrate that 3000w inverter I want hmm (2). Great pick up on the high resistance joint. I think I might put 16 of them in a black plastic container when I get them. Cheers
at 34 minutes when you had both meters next to the product so under the Volt on the BMS it says both how many Ah you used and power in W so you should be able to calibrate it a little better as there was some difference between them but you can do it when you use your viktron shunt to be more accurate. A little advice also as I expect you to install the battery in your shelf so get a switch that has the ability to break on both the positive and negative side (those for cars usually can not handle more than 5-10A) but then you put the resistor on one of the sides and then back on the other side of the switch / fuse so you only need to press it for a few seconds to charge the condensers before switching over the large switch (uses google translation and it wants to use wrong but hope you still understand what I mean)
Thank you. The calibration is a bit nervous on the BMS, I have to test this a bit more to see what the best settings are. All battery banks will have their own breaker in the shelve which acts as an isolator as well. They can isolated individually.
@@OffGridGarageAustralia That with the switch I meant a small one with a resistor on that connects both sides so parallel (so you can charge the capacitors in the inverter under control) there are small switches with several conductors in so you can have both poles through it) also thought when to charge it and if you take it through the shunt you can do a little so they are close with how many watts go through them. Finally, have you checked if they have swelled after you fully charged them?
Great Video as usual, but this knocks it out of the park, even by your standards. Congratulations!!! You are officially my preferred RUclipsr at this moment. Always curious to see what is the next video about! You are the best! Thanks for sharing all this knowledge.
@@OffGridGarageAustralia Setting up my Daly's was far less painless than I thought it would be gonna use four 250 A bms's and will have 1,160 ah 24V then I'll kill my grid connection maybe
I'm starting to rather like this BMS and it looks to be top of my list when I (hopefully soon) get to building my 8S or (preferably) 16S battery to be able to live completely off the power grid. Looking forward to more info on those 300AH cells you recently added...
@@OffGridGarageAustralia Yes indeed Andy, you do need a thermal camera, even 'The Digital Mermaid' mentioned it in her last video and referenced to you :-D
A couple thoughts, why balance starting at 3.4V? If you think about it, that really doesn't make much sense. If you have a cell that is really out of balance then it will kick on active balancing at 3.4V early for all cells. This will not save that cell as it's likely a bad cell or going bad since these cells dont just get out of wack for no reason. Turning on the balancing early will prolong that cell that's going bad early by removing amperage from it and redistributing it to other cells early, especially when charging at higher amperages. Once a Lifepo4 cell goes bad it typically ramps up voltage very rapidly when it hits "100%" state of charge and can easily go up to your cutoff voltage of 3.7V meaning your whole pack terminates charging early. Think it through and let me know what you think. I use this method myself because I've ran into this a couple times already and it works well. I highly recommend avoiding "top balancing" for this reason and I start my balancing early around 3.2V. Some people claim your BMS can't handle this because of its "design", it can.
The balancer will only balance the cells which are over 3.4V and discharge these particular cells. This does not affect the cells which are still under 3.4V. Turning on the balancer earlier will not work with LiFePO4 as all voltages are the same (flat charge curve). Only above 3.4V/3.45V the cell voltage is rising and we can see a difference. If you watch some of the older video, we have thoroughly tested this many times and it is all explained in these videos. LiFePO4 is very different to Li-ion where you can starrt balancing earlier.
@@OffGridGarageAustralia you have a video where you install an active balancer and balance cells at 2.8V so we know that what you just stated is of course incorrect. I've been using these cells for years now and I have my active balancer turned on constantly and I get consistent results. I no longer have issues with my bms deactivating the battery because one cell hit 3.7V too early or 2.5V too soon. This happens when your cells aren't balanced early and your charge current is high like in very good solar production days. You can absolutely use these, and for that matter any cells, this way. You actually do this in your video. You change the active balance voltage to 3.3V at one point. Also, instead of following the method I'm suggesting, which gets better results, to get 100% charge you trickle charge the last 5% at low amperages which really makes no sense. If you'd just balance the cells early, or even leave the active balancer on, you wouldn't need to do this.
I think you'll be pleased with the Daly too if you perform the same test. My dumb Daly has been functioning flawless for several months. What I'd like to see is you do a real world test with the daly. Leave it plugged in for a week with your solar then you'll see you don't need an active balancer or even balancing while discharging for the pack to stay perfectly balanced and protected.
@@OffGridGarageAustralia that's a good question I was wondering that myself. It must start at a fairly low voltage. I was just checking my pack and all the cells are between 3.286 and 3.287 only 1mv deviation you see why I'm very happy with this cheapo. I was expecting a larger deviation being first thing in the morning crazy.
@@OffGridGarageAustralia exactly it's the cheapo that seems to be working as designed quite well. These dumb BMS have a good reputation on the forum a lot better than the newer Bluetooth models. I think the cutoff is at 3.7 I've never had it cut off but I don't see that as a problem. I imagine going from 3.65 to 3.7 would take almost no time. Because charging to 3.7 just for a few minutes I really highly doubt is going to damage the batteries. For me after using it for quite a while 6 months or so now I like the fact that it set that high. The BMS is a last resort protectant that's how I see it. If I had it set lower and it was cutting off let's say weekly that'd be a hassle having to reset it. So at first when I got it I was like wow this makes no sense why would they set the voltage so high for cut off but now I get it.
At around 38:00 I noticed the BMS shows a "Cycle Capacity" of 283.9 at the end of the test. So according to the BMS itself you pulled almost 284 Ah from those cells. I'd wager the BMS is more accurate than that cheap coulomb counter that showed 278, but either way it's still pretty close to the advertised 280 Ah.
I'm not sure how the calibration of the JK BMS works. I thought a full charge will set it to 280Ah and then it counts from there... I need to test more... 😊
@@OffGridGarageAustralia I'm pretty sure that field is telling you the actual Ah that the BMS actually measured being pulled from the battery. Any *good* BMS doesn't take your word for it. When you type in 280 Ah that's just used for a starting point to measure SoC. Most good BMS units will measure the actual AH that's pulled from the battery on every cycle, and use that to judge how many AH the battery can actually hold. Because when it's new, a 280 Ah rated battery may hold 284, but over time it may drop to 270 Ah. The BMS tracks this on every cycle (Which is why it's labeled "cycle capacity") and since this was your first and only cycle it should represent exactly how many Ah the BMS measured being pulled from the cells. By measuring the actual Ah capacity the BMS can give better SoC (And state of health) estimates. If the 280 Ah cells only giv 270 Ah, you want it to read 50% SoC after drawing 135 Ah instead of 140 Ah.
@@OffGridGarageAustralia Oh yeah, that's what I meant: I would bet money that the current sensor in the BMS is calibrated from the factory and much more accurate than that other generic current sensor you were using. I've got a couple of those generic ones that are identical to the one you used in this test that I've used for testing and I've found them to be off by as much as 5%. I'd be willing to bet the one in the JK BMS is calibrated more accurately.
hey, great video, but I got a question. What happens when you exceed the 100a max discharge current? Does it shut off the system or limit the current only?
It will shut off the battery. It's a protection function. Whatever settings gets exceeded (voltage, current temperature), it will disconnect the battery.
Hey Andy. Did the DC measurement device hold it's memory when you were adjusting the busbars on cell nr 6?? If it lost its memory you might have the entire capacity on your battery.
i have a test for you. on your buss bars connection problems. 1 test connection resistance and heating clean and dry then test them again with a little bit of copper never seize on them . what is the difference? besides corrosion protection.
Thanks for the useful videos. At one point you showed a setting in the JK BMS software to set a maximum charge current. That is interesting. What does it do? Does it cut off charging of limit charging? Especially for those people who charge from an alternator, the ability to limit the charge current would be great!
Hi Martin, yes, it will cut of the charging process for the whole battery if this set parameter has been exceeded. It will not limit the charging current though, it's a BMS after all, not a charge controller.
Hello Andy ... I know this is an older video, but have you thought about a test where you actually set the resistance values for each battery wire in the BMS, and see if it makes any difference in the cell voltage deviation, or the speed in which the BMS reacts to deviation?
Hi, great video as usual. I'm curious about a feature that I don't think was covered in the review of the various BMS. Can any of them perform logging? I'm looking forward to the 4S batteries test. Thanks again for the amazing videos.
Thank you for your kind words. 😊 The QUCC does indeed a bit of logging and records the history of reach individual cell. It shows the data in a graph within the app. Not sure if this data can be extracted in any way other way though. 4s test is coming this week.
Have you considered trying to connect the canbus on the BMS to your VenusOS pi? I think device drivers exist for the JKs. Then you could use DVCC on the pi to control the MPPTs.
Great to be in the audience for the testing. As result of this video I ordered the JK BMS. Would it be of any use or just stupid idea to add a second «beefy relay» type BMS protecting the «High High Voltage» moment? If the solar array / regulator went crazy 🤔 Tnx for your work 👍
I agree 100% a thermal camera is an indispensable tool for building and maintaining power distribution systems. I just purchased a FLIR ONE Pro after watching the Digital Mermaid using one. (I am fairly certain that’s the type she was using). Anyway I purchased one and it arrived today. I have had a bit of play with my new toy and it works brilliantly. It appears to be very good value for money when compared to a stand only units with comparable features.
Yes, you can just balance them individually. Charge them to 3.6V and wait for the current to go under 1A. Do this with all cells and put them in series afterwards. There will be a very small imbalance but the BMS or balancer will sort that out.
I can understand using a BMS on an EV, even a scooter, but not on a solar system. The cut off function is not required since the charge controller cuts out before overcharge happens and the inverter cuts out when battery voltage is low. A fuse provides cable burn out protection. Surely you just want a cell monitor!?
A Tesla related question. In The video you mentioned that you have to make a connection between neutral and grund on the inverter, MEN. I have a similiar inverter (12 V, 2000 W) and a 4S 230 AH Lifepo4 battery. Is The connection between neutral and the earth screw on the inverter really necessary when I connect the battery to my Tesla, both the car and the battery/inverter is totally isolated from anything else?
Andy you still need to test the canbus functionality before you give it a seal of approval, it needs to be able to talk to The victron. I think those DC cables should be at least 35mm2.. if you could test the the voltage at the battery terminal and compare it it with the voltage at the inverter terminal underload and see what the voltage drop is.. My inverter is 7kw 48v, and the manufacturer instruction ask for 95mm2 cable.
Hey Andy, great work! To switch bms on you need 5v higher than battery pack, is this a one time switch on, does the unit switch itself off for any reason after initial power on? Me and four friends are purchasing this set up 280ah eve plus jk bms, I can trigger it on, but their know how is not the same. Hence asking this start up question. 👍
I'm so looking forward to building mine just have to get the starting voltage to kick start the BMS. Your thoughts on initial charge of batteries fast charge 50 amp to 3.5v in parallel or slow charge 16 amps or less? will it make a difference other then time?
Hi Andy. Love your YT channel. After seeing your videos on this JK smart BMS with active balancer I purchased the new 8S model for my 24V battery pack on my solar station which provides about 25% of my house electricity needs. However I have a problem that I do not see with your BMS Bluetooth app. My current charge/discharge value displayed on my iPhone app is always jumping all over the place from a few amps to 40 to 50 Amps and not reasonably stable like yours is and as my Overkill smart BMS displays on their iPhone Blue Tooth app when it was used withth esame solar/battery/inverter station. I have written to JK and Heltec (the rebranded JK BMS 8S I have) about this but very rudely and very disappointedly I have not even had an acknowledgement let alone a support reply. I could include a short video but do not know if I can make a short video directly on my phone form the running JK app. So have you seen this problem or has anyone else having this problem too with this iPhone app or do I have a faulty app or faulty BMS??
Hi, which lugs did you use for the P- and B- connection cables of the JK? I ordered 10mm² ring cable lugs and the cable does not fit. What would be the right size? Can I maybe use 16mm²? I want to use euch cable single and not combine them. Thank you 😀
Hi Andy, have you ever tester more than 100 Amps with the JK BMS for let's say about 30 minutes? Does it get much hotter, or does the 7awg wires get hot?
In this case, the victron smartshunt is probably used to verify the BMS. But i often see people use both a BMS and a smartshunt on their batteries, and i wonder why. Is the shunt not doing the same measurements as your bms is doing already (while managing individual cells)? Are people just using these shunts to connect to ve.direct instead of having to play around with CAN, or having ones venusos device talk to both?
I use the Victron Smart Shunt because it easily integrates into the whole system and talks to the other Victron gear. I can read the SOC from anywhere through the app but I need to be in the garage to read the BMS' shunt via Bluetooth. It's an easier option. It is possible to read out the BMS via RS485 or CAN but that's another project again...
Für saubere DC Spannung,gehst du da direkt auf den Block und greifst die 48 Volt ab? Ich hab ein bisschen bedenken mir ein JK zuzulegen wegen der Mosfets und der Fehlfunktion(Jumping up and down ruclips.net/video/edvKvxFpkec/видео.html) wann man viel Amps über das BMS abggreift. Das ist doch eine getaktete Spannung? sowie ich das sehe und bei starker Last bricht das Bms ein bisschen zusammen , das finde ich ein wenig risikoreich. Ist da das Relais BMS nicht besser? klar geht der aktive balancer ab aber gibt zu kaufen , jetzt nicht die die du schon gezeigt hast gibt andere... sind hald sehr teuer Wie alt werden solche BMS?
Should be in the description? Yep, definitely there: PowerPaul Australia (Aluminium Busbars, worldwide shipping): facebook.com/PowerPaul-Australia-103561108175556
Andy, Do you think the balancing power of this BMS is sufficient to use with a 16 cells 280Ah string, but every battery 2 in parrallel? 32 cells total... Or is it dependant on the charge/discharge current? Thanks in advance for the info! Great video's for a newbe like me. Chris from Belgium
I would not recommend adding BMS in series. I guess, you could test it with two and see if it works with all safety features. What's a250V DC system for? That is highly dangerous.
@@OffGridGarageAustralia I need a higher Voltage, 150 -250V for a hybrid 3 phase charger, plan to have 8000Wp solar, around 30kWh battery. The 3 phase inverters need higher voltage as current is around 25A. So probably I really need to rethink harder. In the Netherlands 1 phase solar return may not exceed 4500W if I'm well informed. The battery comes in handy also for storing energy during daytime to later charge my vehicle. In the long term I also want thermodynamic panela for heating and hot water. It's not to go gridless (not allowed in urban areas in NL) but to save a lot of cost as power and natural gas are rising like crazy the last months. But thanks for the warning, I was also very reluctant to design and think of a high voltage DC system. So maybe 3 1phase inverters on 48V but with higher currents will also do the trick, but in the end the system needs to shuffle around 6000Wp from battery and more from solar. It's a puzzle.
I had this problem with the balance cable on cell #1 when I set it up. It's in the first video I did with this BMS. But this was just my crimping quality 😊
@@OffGridGarageAustralia BTW love the video's I used to do video's in the early 2000's on board Motorcycle track footage. I know how much back ground effort it takes to produce a 10 minute video, you vids are great and inspirational. Do you have a grid tied inverter? I'm about to test a 3000 pure sinwave inverter to see if I can get my grid tied inverter to operate when the grid goes off line, as I have 2 6.5kwh LG batteries and 12kwh DIY battery build.
Better control, I guess. Sometimes you cannot series connect 12V li batteries just like that. There are some issues with BMS' in series. I haven't done any testing in this regards though.
So how many kWh ended up in the Tesla's battery? I charge my Model S on excess solar of my off-grid system.....is the icing on the cake. Yes, dogs have Thunder Rights (= they are allowed inside) in my house too.
The meter was on 13.99kWh and I gained 90km from that charge. I haven't charged from the grid for the last 2 weeks now. Sun is really picking up here. It's so cool that I'm able to charge from the battery at night now.
@@OffGridGarageAustralia From these numbers I can see you own a Model 3 and you are a careful driver. 15.6kWh/100km is a low consumption (Yes, Audi, Jaguar, BMW, Mercedes....efficiency is KING and Tesla is the WINNER). Yes to charge at night is great. Best is to have 2 EVs, one charging, one driving.
@@moestrei it is a Model 3, yes. I averaged around 12kWh/100km. If I'm at home during the day I charge from off-grid solar directly. Nothing better than freshly made solar juice 😁
Great video. I recently received JK-B2A8S20P. It seems to work well with 8 x 280K Eve cells. I am waiting on new Victron Multiplus II 2 x 120 split phase to be released in 24VDC in the US. Plan on using this on an RV project. In the interim plan on testing the cells in 4S 2P configuration on my 12 VDC home back-up power system. Am wondering if anyone has used this BMS is a 4S configuration? it's
Andy, you are a LEGEND. Your videos are very thorough and very informative. I have been watching and learning for the last few months. Your hands on approach, with proof in the viewing and providing all your data is so inspiring. I will be changing out my current sealed Gel batteries soon for Lithium and you've sold me on the JK BMS. One question though... Can the JK BMS be paralleled with say another 5 of the exact same unit? I ask because I will be putting 96 cells in a 16s6p configuration. You know, redundancy and those winter days where there isn't enough sun... If you've settled on this BMS and use it in your battery shelf, will you still set the upper cell charge voltage to 3.45 and the lower cutoff to 2.55? Again, thanks for all the effort and time you put in to this in educating and entertaining all of us. All the way from Sunny SA (South Africa)
I've got two in parallel right now and will expand that to 4 soon. 5 should be fine as well, just make sure that if you take a few batteries out, the rest can keep supplying (have a high enough rating together) the required power draw.
Thank you Clynton. You should be able to parallel as many as you want. You would need one BMS for each 16s bank. (Thanks J for beating me again in responding...)
Hey Andy, also if I'm running a 280ah 16s system with victron inverter/ charge controller what amps should I go for with the BMS, 100amp/150amp/200amp? I only ever bring in 70 -80amps and use 4kw out for a short period, mostly 20-50 amp useage? Any recommendations?
Excellent Video! Did the cells noticeably expand? Why don’t you want the BMS to shut off output voltage, but at least run a final balance, for safer cell storage, until the batteries start to get charged again?
Yes, it can somehow. I haven't looked into it yet but there are articles in the DIY forum and also on Github. Also Brad is working on the communication protocols of charge controllers and BMS'.
Hi Andy, I love the show always looking forward to the next one. Hate to be a critic, but is it possible to change the recording frame rate in the camera settings to eliminate the strange strobe effect on the charger display, apparently Australia is 50hz so perhaps try 25fps? or multiples of that
Thanks Kirk. Good suggestion. I have the camera on 60FPS as this is what I broadcast later on RUclips. I do some testing with 50FPS setting in the camera. I recall there were some other issues with lights though but maybe that's gone now because I have the LED lights in the garage now.
@@OffGridGarageAustralia No Problem, Again i love the show, we will be going offgrid as soon as the parts arrive. Thankyou for experimenting so I don't have to. Off topic, but I just watched your ev car show and noticed you drove to Gatton. I always thought from your videos that your in such a beautiful part of the world, but I had a bad experience in Gatton. I was backpacking around 15 years ago and found myself low on funds, so I went to Gatton as I heard there were easy to get jobs on tomato farms. I stayed the night in a Caravan park (I've never seen such a dirty mattress in my life)... anyway I took a walk just after arriving, I had dinner at kfc, after that I saw a another backpacker on the main street waiting on a bench for the bus(she came for work but was unable to find any), i started talking to her, and a very tall and presumably drunk pacific islander came walking out of a pub looked at me and I made the mistake of making eye contact with him. As I was still sitting down on the bench as he stood over me pounding me in the face, messed me up pretty bad, I lost interest in the potential farm job and flew home.. needed surgery and still suffer from headaches till this day.... Sorry about the long reply, just seeing Gatton after all these years brought back those memories. If I hadn't have had that bad experience then other than that my first impressions was that it is a beautiful town.
During your latest video I notice you have Balancing running but the App dashboard is not showing any Balance Current...I'll check mine tomorrow but I'm sure mine displays Balance Cur:
It only displays the balancing current when it's actually balancing. If the delta between cells is too low, or the voltage of the cells below the threshold, it doesn't balance.
Andy, I notice JK-BMS has balance lead impedance compensation. Hookup wire has about 70mohm/m so at 2A it will drop 0.15V and that is significant. This may give better balance operation. Can you test that out?
We need to remember, that the balancer does not work all the time. It either sucks in energy from high voltage cells or gives this energy to low voltage cells. This operation is only for 10s or so. The BMS has then time to measure the voltage again without load on the balance leads.
@@OffGridGarageAustralia Sounds reasonable. So why do they have programmable balance lead impedance. Maybe they are measuring voltage while passing current?
@@peterdkay yeah, that's a good question actually. At the beginning I found this a useful feature to compensate for voltage drop but seeing how the balance function works, it does not make so much sense anymore. Maybe the software is so sophisticated that it can determine a better SOC reading while balancing (charging) from the two voltage readings, one with load one without load through the balance cables. That's a wild guess, I know ☺️
@@OffGridGarageAustralia I notice cells being balanced bounce all over the place. Maybe putting in 50mohm of balance lead compensation will slow down the bouncing.
I have now fallen in love with the jk bms, but its a long distance relationship. Any ideas how to access this bms over long distance, maybe connecting to wifi instead of using Bluetooth? I would love to see a solution to this, because ive tried connecting a tablet and using teamviewer, ive tried setting up a security camera pointed at a connected tablet, but yet to have any consistent luck with connecting reliably. Any better solution id love to hear about! ☺
Hey Andy, I have a test for you to do with the JK BMS. I heard you can get a cheap 12v to 48v buck converter and use that to supply cell 16 on the BMS, then you can use the JK as a BMS with active balancer on a 4S 12v LiFePo battery. Feel like testing it with your 100AH cells?
I opened one (the 100A version) up and posted pictures on the DIY site, including a link to the MOSFET datasheet etc. Long story short: you don't need to down-rate the BMS; the design is not pushing the MOSFETS and has a safety margin by design.
Thank you, J.
Links are here
diysolarforum.com/threads/bms-mosfets-explained.29318/
and
diysolarforum.com/threads/jbd-overkill-vs-jk-heltec-bms.29309/post-352783
Definitely good to know that they’re designed for 100% rated operation. Still it doesn’t hurt to derate them a little bit to give it some headroom. From experience, it is less stress on the MOSFETs.
@@OffGridGarageAustralia Für saubere DC Spannung,gehst du da direkt auf den Block und greifst die 48 Volt ab?
Ich hab ein bisschen bedenken mir ein JK zuzulegen
wegen der Mosfets und der Fehlfunktion(Jumping up and down ruclips.net/video/edvKvxFpkec/видео.html) wann man viel Amps über das BMS abggreift.
Das ist doch eine getaktete Spannung? sowie ich das sehe und bei starker Last bricht das Bms ein bisschen zusammen , das finde ich ein wenig risikoreich.
Ist da das Relais BMS nicht besser? klar geht der aktive balancer ab aber gibt es ja zu kaufen , jetzt nicht die die du schon gezeigt hast gibt andere... sind hald sehr teuer
Wie alt werden solche BMS?
@@BavarianSuperGuy Sind halt halbleiterprodukte. Scheint aber sehr robust zu sein. Kann also schon sehr alt werden. Wo bricht das BMS ein? Die Spannung geht bei der Last runter, das hat aber mehr mit dem Innenwiderstand der Batterie zu tun. So ein Relais zieht Dauerhaft Strom (oder sind das bistabile?) da ist dies hier schon deutlich effizienter.
Andy! your videos are better than Netflix . congratulations for such a good content and editing.
Wow, thanks a lot! 😊
I think this is the BMS i will go for when I build my system. Thank you for a very good video! :) Cheers from Norway!
Thanks Peter. I really love this BMS and app. it just works, is easy to setup and configure and saves you an additional balancer.
The BMS' current reporting jumps up and down by 10% probably because its averaging period is too short to smooth out the current ripples from the inverter's 50Hz output, so it reads different current depending on what point of the AC sine wave the inverter is at. Keep in mind that the instantaneous peak power of a resistive AC load is double the RMS value, so the inverter's output stage is pulling nearly 100A from its internal capacitors, your BMS is seeing the leftover ripples.
The Daly does this too, it's pretty annoying. But I've found they do vary a lot, some are really stable, and some are very jumpy.
Thanks Dan, that's a nice explanation. Makes sense. Other BMS's don't do that as far as I have seen, they show an average of the last 5s or so...
Excellent testing Andy. You always keep us on the edge of our seats during your bench testing! As usual, a video packed with valid information.
Thank you very much, Kevin.
Bought 2 immidiately when i saw "Andy tested them - and nice!". Now i also looked the video, thank you again su much!!
Thanks, Andy!
Good morning Andy from Italy. I discovered your channel and I want to congratulate you because it is very funny and technically perfect. I already have a JK BMS in a battery pack in my RV, home built. I also tested how the internal balancer works. I did it by charging the batteries with a 30A charger. The balancer works fine up to a certain point, then loses working capacity when you are over 90% charged or under 10% (2A vs 30A are not enough, i think). The gap has risen above 100mV. Maybe my battreies aren't that good.. I'll keep within those limits
Thanks and good job
Thanks a lot Manlio. What voltage do you charge to and what is your balance start voltage? Balancing at 30A charging makes not much sense...
Super test !!! Top batteries !!! I like this video very much. I think you spend a lot of time editing this 40:55min video. Good work ! 👏 I appreciate !
Thank you very much Alex. I really appreciate you appreciate the videos and effort. The whole editing part is killing me. Timewise... This one took like 7h 🤦♂️ Not many people see all the work behind that. So thank you again!
Pretty dang good correlation among a bunch of el cheapo measuring devices that are not even calibrated. Your kluged up system is working very well in a real world environment.
Yeah, this is working pretty darn good so far.
Man... you are so competent but mainly......so pleasent!!! I am becoming an off-grid garage enthusiast !!!!!
That's the way! Thank you Paolo 😊
After a bit more then a year I've started to have issues with my Daly bms, the balancing is so far out now that the daly just can't keep up and is shutting the charging mosfet at 85% SOC. Just purchased two of these jk bms's to help solve this issue. thanks for the video and amazing testing, back to trickle charging my cells in hopes the daly can balance some of this issue back out while the jk's are in the mail. Used your links hope you get some kick back!!
Wow, what a test. Excellent Andy.
Dear Andy, First of all thank you very much for these very good and clear video's. It really helped me a lot. I bought the JK BMS and I want to use it for my battery pack 15S3P with EVE cells of each 280Ah. The balancing functioning is crucial for these large batteries I think. Actually you convenced me :). Now a friend told me that the JK BMS is not suitable to handle parallel cells. Now I do not know what to do anymore. Can you please try to clear this up. I can't understand why a JK BMS can not handle the three parallel cells. He also told that a Daly BMS can handle the 3 parallel cells. Kind regards Wouter Swart from the Netherlands
This is such compelling battery testing with instructions and information about so many details. Thank you so much Andy.
I took the plunge and started buying components and tools.
Battery (24v, 280ah Saben eve) should arrive in a month or so.
But...i am still searching online to buy a bit of that perfect ambient temp for my offgrid cabin situated in north Europe.
très beau TEST !!! vraiment surprenant sur tout pour une décharge si longue.
Nice video! I ordered 1 jk bms after watching your video!
Hope you enjoy it! It' will be great. I really love it and cannot wait to replace the QUCC BMS with the JK.
Thanks for the education that you provide with your videos.
Thanks to you I’m in the next couple months going to buy (through your links) 50 304 amp hour batteries and three BMS.
Going to build 3 48 volt packs with 2 extra batteries (just in case).
Looking forward to your shelf build because that’s what I’m building.
Again thank you very much
Thank YOU very much for sharing and using the links. That's a great support for the channel!
@@margarita8442 yes, that's the plan
@@margarita8442 no In serious
Series
@@tinasholly2434 yes 16 cells in series but 3 of these 16s batteries in parallel.
Great show again Andy. I want one!! Hang on I said that when you tested the first lot of EVE cells, so I got 12v worth. I couldn't be happier. Yes integrate that 3000w inverter I want hmm (2). Great pick up on the high resistance joint. I think I might put 16 of them in a black plastic container when I get them. Cheers
Yeah, the black plastic container works well so far 😂
Welcome again to the Oz Grid Garage 😁
That's great, Oz-Grid Garage 😂
Thanks Andy, an other good test (you save me a lot of work)👍
Thanks Wayne. Hahaha, yeah, it takes sooo long. I usually have 2-3 tests running at the same time
You should get one of these FLIR TG165-X Thermal Camera... I don't know how I ever did without it!
at 34 minutes when you had both meters next to the product so under the Volt on the BMS it says both how many Ah you used and power in W so you should be able to calibrate it a little better as there was some difference between them but you can do it when you use your viktron shunt to be more accurate. A little advice also as I expect you to install the battery in your shelf so get a switch that has the ability to break on both the positive and negative side (those for cars usually can not handle more than 5-10A) but then you put the resistor on one of the sides and then back on the other side of the switch / fuse so you only need to press it for a few seconds to charge the condensers before switching over the large switch
(uses google translation and it wants to use wrong but hope you still understand what I mean)
Thank you. The calibration is a bit nervous on the BMS, I have to test this a bit more to see what the best settings are.
All battery banks will have their own breaker in the shelve which acts as an isolator as well. They can isolated individually.
@@OffGridGarageAustralia That with the switch I meant a small one with a resistor on that connects both sides so parallel (so you can charge the capacitors in the inverter under control) there are small switches with several conductors in so you can have both poles through it)
also thought when to charge it and if you take it through the shunt you can do a little so they are close with how many watts go through them.
Finally, have you checked if they have swelled after you fully charged them?
Andy depending on how my finances go i may buy the same batteries you have. and the BMS They are rock solid.
They are both fantastic. It's a great combo!
Great Video as usual, but this knocks it out of the park, even by your standards. Congratulations!!! You are officially my preferred RUclipsr at this moment. Always curious to see what is the next video about! You are the best! Thanks for sharing all this knowledge.
Thanks so much for you comment and kind words!
Only just discovered your videos - really enjoy them. Thanks!
Very nice very comprehensive interface
and it just works... all settings are easy to understand and program and the BMS just follows these settings.
@@OffGridGarageAustralia nice
@@OffGridGarageAustralia Setting up my Daly's was far less painless than I thought it would be gonna use four 250 A bms's and will have 1,160 ah 24V then I'll kill my grid connection maybe
I'm starting to rather like this BMS and it looks to be top of my list when I (hopefully soon) get to building my 8S or (preferably) 16S battery to be able to live completely off the power grid. Looking forward to more info on those 300AH cells you recently added...
I'll show you how to connect this BMS to a 12V and also 24V battery in a video soon.
@@OffGridGarageAustralia I was just about to ask if this active BMS could operate on lower cell counts for 12 & 24V systems.
My JK is connected to a 6,4 kw 14s LG Chem pack and top and bottom balance is spot on , I use 0.5A balance current. Running for 2 years 👍
Thanks for sharing, that's good to hear. It's a great BMS!
Great video. The bns does look very good.
Yes it does. I really like it. BMS and app work without problems so far...
Amazing what a little investigatiion can do. Great vid thanks
What investigation do you mean?
I do
Hey up Andy I see you like your temp gun ....what you need is a thermal imaging gun ...you would love it
I know 😉
@@OffGridGarageAustralia Yes indeed Andy, you do need a thermal camera, even 'The Digital Mermaid' mentioned it in her last video and referenced to you :-D
@@ValRigoli Hahaha, she mentions me all the time so I keep watching and listen what she says about me 😂
Andy, I like the fact that you don’t take yourself too seriously. And trust me when I tell you, we don’t take you seriously ether! Ha ha!!
Good video!!
Thank you very much!
A couple thoughts, why balance starting at 3.4V? If you think about it, that really doesn't make much sense. If you have a cell that is really out of balance then it will kick on active balancing at 3.4V early for all cells. This will not save that cell as it's likely a bad cell or going bad since these cells dont just get out of wack for no reason. Turning on the balancing early will prolong that cell that's going bad early by removing amperage from it and redistributing it to other cells early, especially when charging at higher amperages. Once a Lifepo4 cell goes bad it typically ramps up voltage very rapidly when it hits "100%" state of charge and can easily go up to your cutoff voltage of 3.7V meaning your whole pack terminates charging early. Think it through and let me know what you think. I use this method myself because I've ran into this a couple times already and it works well. I highly recommend avoiding "top balancing" for this reason and I start my balancing early around 3.2V. Some people claim your BMS can't handle this because of its "design", it can.
The balancer will only balance the cells which are over 3.4V and discharge these particular cells. This does not affect the cells which are still under 3.4V.
Turning on the balancer earlier will not work with LiFePO4 as all voltages are the same (flat charge curve). Only above 3.4V/3.45V the cell voltage is rising and we can see a difference.
If you watch some of the older video, we have thoroughly tested this many times and it is all explained in these videos.
LiFePO4 is very different to Li-ion where you can starrt balancing earlier.
@@OffGridGarageAustralia you have a video where you install an active balancer and balance cells at 2.8V so we know that what you just stated is of course incorrect. I've been using these cells for years now and I have my active balancer turned on constantly and I get consistent results. I no longer have issues with my bms deactivating the battery because one cell hit 3.7V too early or 2.5V too soon. This happens when your cells aren't balanced early and your charge current is high like in very good solar production days. You can absolutely use these, and for that matter any cells, this way. You actually do this in your video. You change the active balance voltage to 3.3V at one point. Also, instead of following the method I'm suggesting, which gets better results, to get 100% charge you trickle charge the last 5% at low amperages which really makes no sense. If you'd just balance the cells early, or even leave the active balancer on, you wouldn't need to do this.
Got my eve 280ah and jk bms thanks andy
Great test!
Thank you!
I think you'll be pleased with the Daly too if you perform the same test. My dumb Daly has been functioning flawless for several months. What I'd like to see is you do a real world test with the daly. Leave it plugged in for a week with your solar then you'll see you don't need an active balancer or even balancing while discharging for the pack to stay perfectly balanced and protected.
When do you start balancing with yours? What's the start voltage for that?
@@OffGridGarageAustralia that's a good question I was wondering that myself. It must start at a fairly low voltage. I was just checking my pack and all the cells are between 3.286 and 3.287 only 1mv deviation you see why I'm very happy with this cheapo. I was expecting a larger deviation being first thing in the morning crazy.
@@farmerjhemp that's just a dump BMS without BT, right?
@@OffGridGarageAustralia exactly it's the cheapo that seems to be working as designed quite well. These dumb BMS have a good reputation on the forum a lot better than the newer Bluetooth models. I think the cutoff is at 3.7 I've never had it cut off but I don't see that as a problem. I imagine going from 3.65 to 3.7 would take almost no time. Because charging to 3.7 just for a few minutes I really highly doubt is going to damage the batteries. For me after using it for quite a while 6 months or so now I like the fact that it set that high. The BMS is a last resort protectant that's how I see it. If I had it set lower and it was cutting off let's say weekly that'd be a hassle having to reset it. So at first when I got it I was like wow this makes no sense why would they set the voltage so high for cut off but now I get it.
@@farmerjhemp Yep, that makes sense. I agree with you on that. You've never tested the cut-off, I assume? I would have 😁
enjoyable wideo, as always
Thanks a lot!
At around 38:00 I noticed the BMS shows a "Cycle Capacity" of 283.9 at the end of the test. So according to the BMS itself you pulled almost 284 Ah from those cells. I'd wager the BMS is more accurate than that cheap coulomb counter that showed 278, but either way it's still pretty close to the advertised 280 Ah.
I'm not sure how the calibration of the JK BMS works. I thought a full charge will set it to 280Ah and then it counts from there... I need to test more... 😊
@@OffGridGarageAustralia I'm pretty sure that field is telling you the actual Ah that the BMS actually measured being pulled from the battery.
Any *good* BMS doesn't take your word for it. When you type in 280 Ah that's just used for a starting point to measure SoC. Most good BMS units will measure the actual AH that's pulled from the battery on every cycle, and use that to judge how many AH the battery can actually hold. Because when it's new, a 280 Ah rated battery may hold 284, but over time it may drop to 270 Ah. The BMS tracks this on every cycle (Which is why it's labeled "cycle capacity") and since this was your first and only cycle it should represent exactly how many Ah the BMS measured being pulled from the cells.
By measuring the actual Ah capacity the BMS can give better SoC (And state of health) estimates. If the 280 Ah cells only giv 270 Ah, you want it to read 50% SoC after drawing 135 Ah instead of 140 Ah.
@@JeremyAkersInAustin that all works fine if the current sensor is calibrated correctly. So there might be some error in this as well.
@@OffGridGarageAustralia Oh yeah, that's what I meant: I would bet money that the current sensor in the BMS is calibrated from the factory and much more accurate than that other generic current sensor you were using. I've got a couple of those generic ones that are identical to the one you used in this test that I've used for testing and I've found them to be off by as much as 5%. I'd be willing to bet the one in the JK BMS is calibrated more accurately.
hey, great video, but I got a question. What happens when you exceed the 100a max discharge current? Does it shut off the system or limit the current only?
It will shut off the battery. It's a protection function. Whatever settings gets exceeded (voltage, current temperature), it will disconnect the battery.
Hey Andy.
Did the DC measurement device hold it's memory when you were adjusting the busbars on cell nr 6?? If it lost its memory you might have the entire capacity on your battery.
Yes, they save all the settings. You have to hold this button for a few seconds and go into the menu of the meter to reset them.
i have a test for you. on your buss bars connection problems. 1 test connection resistance and heating clean and dry then test them again with a little bit of copper never seize on them . what is the difference? besides corrosion protection.
great to know/thanks much
No problem!
Thanks for the useful videos. At one point you showed a setting in the JK BMS software to set a maximum charge current. That is interesting. What does it do? Does it cut off charging of limit charging? Especially for those people who charge from an alternator, the ability to limit the charge current would be great!
Hi Martin, yes, it will cut of the charging process for the whole battery if this set parameter has been exceeded.
It will not limit the charging current though, it's a BMS after all, not a charge controller.
Hello Andy ... I know this is an older video, but have you thought about a test where you actually set the resistance values for each battery wire in the BMS, and see if it makes any difference in the cell voltage deviation, or the speed in which the BMS reacts to deviation?
nice video and inverter with bms are still on sale.. most times they re gone sellout
Hi, great video as usual. I'm curious about a feature that I don't think was covered in the review of the various BMS. Can any of them perform logging?
I'm looking forward to the 4S batteries test.
Thanks again for the amazing videos.
Thank you for your kind words. 😊
The QUCC does indeed a bit of logging and records the history of reach individual cell. It shows the data in a graph within the app. Not sure if this data can be extracted in any way other way though.
4s test is coming this week.
Good. I think that is the latest solution. Can Paul do the gold plate on the battery contact bar. then would be much better I think.
Have you considered trying to connect the canbus on the BMS to your VenusOS pi? I think device drivers exist for the JKs. Then you could use DVCC on the pi to control the MPPTs.
Yes, that's all in planning and I will do detailed videos on this for everyone to follow.
Great to be in the audience for the testing. As result of this video I ordered the JK BMS. Would it be of any use or just stupid idea to add a second «beefy relay» type BMS protecting the «High High Voltage» moment? If the solar array / regulator went crazy 🤔 Tnx for your work 👍
You should have a thermal camera to check for any looseness of connections. I always use it, it is amazing tool.
Which one do you have?
@@OffGridGarageAustralia
A-BF RX-700
I agree 100% a thermal camera is an indispensable tool for building and maintaining power distribution systems. I just purchased a FLIR ONE Pro after watching the Digital Mermaid using one. (I am fairly certain that’s the type she was using). Anyway I purchased one and it arrived today. I have had a bit of play with my new toy and it works brilliantly. It appears to be very good value for money when compared to a stand only units with comparable features.
@@michaelhayward9919 Great feedback. I'll ask Madi what she's using and will order one too. Thanks for sharing.
@@EhsanAlnazi Thank you! Wow, $1400 😯
How can I enter the settings with a 72V 20-line battery
Andy, I have 4 cells and 4 busbars. Can I balance them 3 at a time? ie balance 3, disconnect 1, connect the other one?
Yes, you can just balance them individually. Charge them to 3.6V and wait for the current to go under 1A. Do this with all cells and put them in series afterwards. There will be a very small imbalance but the BMS or balancer will sort that out.
I ordered a JK BMS with a small display which has a switch to turn the BMS on.
I can understand using a BMS on an EV, even a scooter, but not on a solar system.
The cut off function is not required since the charge controller cuts out before overcharge happens and the inverter cuts out when battery voltage is low.
A fuse provides cable burn out protection.
Surely you just want a cell monitor!?
King 🤴.....
My friend... i have two questions who amp is this jk bms and the batterys are new or how old is?
Thanks
A Tesla related question. In The video you mentioned that you have to make a connection between neutral and grund on the inverter, MEN. I have a similiar inverter (12 V, 2000 W) and a 4S 230 AH Lifepo4 battery. Is The connection between neutral and the earth screw on the inverter really necessary when I connect the battery to my Tesla, both the car and the battery/inverter is totally isolated from anything else?
Andy you still need to test the canbus functionality before you give it a seal of approval, it needs to be able to talk to The victron.
I think those DC cables should be at least 35mm2.. if you could test the the voltage at the battery terminal and compare it it with the voltage at the inverter terminal underload and see what the voltage drop is..
My inverter is 7kw 48v, and the manufacturer instruction ask for 95mm2 cable.
I will, but not soon I believe. This will be a whole new sphere we will be walking in. Apparently there is some info in the DIY Solar Forum...
Andy Approved Award or just "Triple A" stamp from Andy
Hahaha, that's great!
Hey Andy, great work! To switch bms on you need 5v higher than battery pack, is this a one time switch on, does the unit switch itself off for any reason after initial power on?
Me and four friends are purchasing this set up 280ah eve plus jk bms, I can trigger it on, but their know how is not the same. Hence asking this start up question. 👍
Thanks!
Thank you very much!
Very good, thanks :) I need much more power - up to 45kW on the AC side, 3 phase. So HV battery pack and there are no similar balancers for these :(
I think you can use sofarsolar gyd 15kw x3 in paralel. And for the battery you need to make 24s packs x5 in series to make HV battery.
I'm so looking forward to building mine just have to get the starting voltage to kick start the BMS. Your thoughts on initial charge of batteries fast charge 50 amp to 3.5v in parallel or slow charge 16 amps or less? will it make a difference other then time?
I wonder if that BMS will allow you to set a longer sampling/averaging period, so the display is not jumping around so quickly all the time?
Doesn't seem to be an option...
great job mate cheers :-)
Thank you! Cheers!
Hi Andy. Love your YT channel. After seeing your videos on this JK smart BMS with active balancer I purchased the new 8S model for my 24V battery pack on my solar station which provides about 25% of my house electricity needs.
However I have a problem that I do not see with your BMS Bluetooth app. My current charge/discharge value displayed on my iPhone app is always jumping all over the place from a few amps to 40 to 50 Amps and not reasonably stable like yours is and as my Overkill smart BMS displays on their iPhone Blue Tooth app when it was used withth esame solar/battery/inverter station. I have written to JK and Heltec (the rebranded JK BMS 8S I have) about this but very rudely and very disappointedly I have not even had an acknowledgement let alone a support reply. I could include a short video but do not know if I can make a short video directly on my phone form the running JK app.
So have you seen this problem or has anyone else having this problem too with this iPhone app or do I have a faulty app or faulty BMS??
Hi,
which lugs did you use for the P- and B- connection cables of the JK? I ordered 10mm² ring cable lugs and the cable does not fit. What would be the right size? Can I maybe use 16mm²?
I want to use euch cable single and not combine them.
Thank you 😀
Hi Andy, have you ever tester more than 100 Amps with the JK BMS for let's say about 30 minutes?
Does it get much hotter, or does the 7awg wires get hot?
In this case, the victron smartshunt is probably used to verify the BMS. But i often see people use both a BMS and a smartshunt on their batteries, and i wonder why. Is the shunt not doing the same measurements as your bms is doing already (while managing individual cells)? Are people just using these shunts to connect to ve.direct instead of having to play around with CAN, or having ones venusos device talk to both?
I use the Victron Smart Shunt because it easily integrates into the whole system and talks to the other Victron gear. I can read the SOC from anywhere through the app but I need to be in the garage to read the BMS' shunt via Bluetooth. It's an easier option. It is possible to read out the BMS via RS485 or CAN but that's another project again...
@@OffGridGarageAustralia Good to know, and makes sense.
Für saubere DC Spannung,gehst du da direkt auf den Block und greifst die 48 Volt ab?
Ich hab ein bisschen bedenken mir ein JK zuzulegen
wegen der Mosfets und der Fehlfunktion(Jumping up and down ruclips.net/video/edvKvxFpkec/видео.html) wann man viel Amps über das BMS abggreift.
Das ist doch eine getaktete Spannung? sowie ich das sehe und bei starker Last bricht das Bms ein bisschen zusammen , das finde ich ein wenig risikoreich.
Ist da das Relais BMS nicht besser? klar geht der aktive balancer ab aber gibt zu kaufen , jetzt nicht die die du schon gezeigt hast gibt andere... sind hald sehr teuer
Wie alt werden solche BMS?
Am I missing where the link is for Paul’s bus bars?
Should be in the description?
Yep, definitely there:
PowerPaul Australia (Aluminium Busbars, worldwide shipping):
facebook.com/PowerPaul-Australia-103561108175556
Moje pieski jak zbliża się burza też przychodzą do garażu i zawsze ścielam im ciepły koc na podłogę 😅
Andy, Do you think the balancing power of this BMS is sufficient to use with a 16 cells 280Ah string, but every battery 2 in parrallel? 32 cells total... Or is it dependant on the charge/discharge current? Thanks in advance for the info! Great video's for a newbe like me. Chris from Belgium
Great as always, great it's Andy approved. Can 5 or 6 JK BMSes run serially, I am planning a 250V DC combined via 5 packs.
I would not recommend adding BMS in series. I guess, you could test it with two and see if it works with all safety features. What's a250V DC system for? That is highly dangerous.
@@OffGridGarageAustralia I need a higher Voltage, 150 -250V for a hybrid 3 phase charger, plan to have 8000Wp solar, around 30kWh battery. The 3 phase inverters need higher voltage as current is around 25A. So probably I really need to rethink harder. In the Netherlands 1 phase solar return may not exceed 4500W if I'm well informed. The battery comes in handy also for storing energy during daytime to later charge my vehicle. In the long term I also want thermodynamic panela for heating and hot water. It's not to go gridless (not allowed in urban areas in NL) but to save a lot of cost as power and natural gas are rising like crazy the last months. But thanks for the warning, I was also very reluctant to design and think of a high voltage DC system. So maybe 3 1phase inverters on 48V but with higher currents will also do the trick, but in the end the system needs to shuffle around 6000Wp from battery and more from solar. It's a puzzle.
"Yes, I'm wearing my glasses"
People are concerned, you know, so I mentioned it👓
@@OffGridGarageAustralia safety at least third!
I have a 0.6 amp balancer in jk BMS. Can I change the 2 capacitors to increase my balancing capacitance to 2 amps
Andy have you checked the balancing/sense wires I had a cell kept going all over the place do to a poor connection. With this BMS.
I had this problem with the balance cable on cell #1 when I set it up. It's in the first video I did with this BMS. But this was just my crimping quality 😊
@@OffGridGarageAustralia BTW love the video's I used to do video's in the early 2000's on board Motorcycle track footage. I know how much back ground effort it takes to produce a 10 minute video, you vids are great and inspirational. Do you have a grid tied inverter? I'm about to test a 3000 pure sinwave inverter to see if I can get my grid tied inverter to operate when the grid goes off line, as I have 2 6.5kwh LG batteries and 12kwh DIY battery build.
well if you will check Victron energy charger they use 35mm*mm for 100A current ..so it should be ok for you :)
What is the benefit of having multiple cells in series vs having a 12v battery for example?
Better control, I guess. Sometimes you cannot series connect 12V li batteries just like that. There are some issues with BMS' in series. I haven't done any testing in this regards though.
Two awesome tests, thanks, but why only this brand?
You mean the batteries? I don't know. Had good experience so for with EVE so I stick to them.
So how many kWh ended up in the Tesla's battery? I charge my Model S on excess solar of my off-grid system.....is the icing on the cake. Yes, dogs have Thunder Rights (= they are allowed inside) in my house too.
The meter was on 13.99kWh and I gained 90km from that charge. I haven't charged from the grid for the last 2 weeks now. Sun is really picking up here. It's so cool that I'm able to charge from the battery at night now.
@@OffGridGarageAustralia From these numbers I can see you own a Model 3 and you are a careful driver. 15.6kWh/100km is a low consumption (Yes, Audi, Jaguar, BMW, Mercedes....efficiency is KING and Tesla is the WINNER). Yes to charge at night is great. Best is to have 2 EVs, one charging, one driving.
@@moestrei it is a Model 3, yes. I averaged around 12kWh/100km. If I'm at home during the day I charge from off-grid solar directly. Nothing better than freshly made solar juice 😁
Great video. I recently received JK-B2A8S20P. It seems to work well with 8 x 280K Eve cells. I am waiting on new Victron Multiplus II 2 x 120 split phase to be released in 24VDC in the US. Plan on using this on an RV project. In the interim plan on testing the cells in 4S 2P configuration on my 12 VDC home back-up power system. Am wondering if anyone has used this BMS is a 4S configuration? it's
Hi Andy, have you had the chance to test the MPI 5K Inverter from MPP Solar? Or do you have a comment on it? Cheers Torsten
Hello my friend, I want to use BMS JK on an electric bike. Do I need to start it every time or only the first time? I mean, on of
Andy, you are a LEGEND. Your videos are very thorough and very informative. I have been watching and learning for the last few months. Your hands on approach, with proof in the viewing and providing all your data is so inspiring. I will be changing out my current sealed Gel batteries soon for Lithium and you've sold me on the JK BMS. One question though... Can the JK BMS be paralleled with say another 5 of the exact same unit? I ask because I will be putting 96 cells in a 16s6p configuration. You know, redundancy and those winter days where there isn't enough sun...
If you've settled on this BMS and use it in your battery shelf, will you still set the upper cell charge voltage to 3.45 and the lower cutoff to 2.55?
Again, thanks for all the effort and time you put in to this in educating and entertaining all of us. All the way from Sunny SA (South Africa)
I've got two in parallel right now and will expand that to 4 soon. 5 should be fine as well, just make sure that if you take a few batteries out, the rest can keep supplying (have a high enough rating together) the required power draw.
Thank you Clynton. You should be able to parallel as many as you want. You would need one BMS for each 16s bank.
(Thanks J for beating me again in responding...)
Hey Andy, also if I'm running a 280ah 16s system with victron inverter/ charge controller what amps should I go for with the BMS, 100amp/150amp/200amp? I only ever bring in 70 -80amps and use 4kw out for a short period, mostly 20-50 amp useage? Any recommendations?
Hello. Sir, can you do a review of EASUN MPPT 60A? waiting and thank you.
Hello , why u are not soldered the wires , just u are only pressed them? thanks
Excellent Video!
Did the cells noticeably expand?
Why don’t you want the BMS to shut off output voltage, but at least run a final balance, for safer cell storage, until the batteries start to get charged again?
No, I never saw then expand or contract with any of my tests.
Can the JK BMS also be connected to Victron via CAN or RS485?
Yes, it can somehow. I haven't looked into it yet but there are articles in the DIY forum and also on Github. Also Brad is working on the communication protocols of charge controllers and BMS'.
Hi Andy, I love the show always looking forward to the next one.
Hate to be a critic, but is it possible to change the recording frame rate in the camera settings to eliminate the strange strobe effect on the charger display, apparently Australia is 50hz so perhaps try 25fps? or multiples of that
Thanks Kirk. Good suggestion. I have the camera on 60FPS as this is what I broadcast later on RUclips. I do some testing with 50FPS setting in the camera. I recall there were some other issues with lights though but maybe that's gone now because I have the LED lights in the garage now.
@@OffGridGarageAustralia No Problem, Again i love the show, we will be going offgrid as soon as the parts arrive. Thankyou for experimenting so I don't have to.
Off topic, but I just watched your ev car show and noticed you drove to Gatton. I always thought from your videos that your in such a beautiful part of the world, but I had a bad experience in Gatton. I was backpacking around 15 years ago and found myself low on funds, so I went to Gatton as I heard there were easy to get jobs on tomato farms. I stayed the night in a Caravan park (I've never seen such a dirty mattress in my life)... anyway I took a walk just after arriving, I had dinner at kfc, after that I saw a another backpacker on the main street waiting on a bench for the bus(she came for work but was unable to find any), i started talking to her, and a very tall and presumably drunk pacific islander came walking out of a pub looked at me and I made the mistake of making eye contact with him. As I was still sitting down on the bench as he stood over me pounding me in the face, messed me up pretty bad, I lost interest in the potential farm job and flew home.. needed surgery and still suffer from headaches till this day....
Sorry about the long reply, just seeing Gatton after all these years brought back those memories.
If I hadn't have had that bad experience then other than that my first impressions was that it is a beautiful town.
During your latest video I notice you have Balancing running but the App dashboard is not showing any Balance Current...I'll check mine tomorrow but I'm sure mine displays Balance Cur:
It only displays the balancing current when it's actually balancing. If the delta between cells is too low, or the voltage of the cells below the threshold, it doesn't balance.
@@upnorthandpersonal I thought the video was showing it balancing, I'll need to watch the video again...
Nice 👍🏻
Thanks ✌️
Andy, I notice JK-BMS has balance lead impedance compensation. Hookup wire has about 70mohm/m so at 2A it will drop 0.15V and that is significant.
This may give better balance operation.
Can you test that out?
We need to remember, that the balancer does not work all the time. It either sucks in energy from high voltage cells or gives this energy to low voltage cells. This operation is only for 10s or so. The BMS has then time to measure the voltage again without load on the balance leads.
@@OffGridGarageAustralia Sounds reasonable. So why do they have programmable balance lead impedance. Maybe they are measuring voltage while passing current?
@@peterdkay yeah, that's a good question actually. At the beginning I found this a useful feature to compensate for voltage drop but seeing how the balance function works, it does not make so much sense anymore. Maybe the software is so sophisticated that it can determine a better SOC reading while balancing (charging) from the two voltage readings, one with load one without load through the balance cables.
That's a wild guess, I know ☺️
@@OffGridGarageAustralia I notice cells being balanced bounce all over the place. Maybe putting in 50mohm of balance lead compensation will slow down the bouncing.
I have now fallen in love with the jk bms, but its a long distance relationship. Any ideas how to access this bms over long distance, maybe connecting to wifi instead of using Bluetooth? I would love to see a solution to this, because ive tried connecting a tablet and using teamviewer, ive tried setting up a security camera pointed at a connected tablet, but yet to have any consistent luck with connecting reliably. Any better solution id love to hear about! ☺
Hey Andy, I have a test for you to do with the JK BMS. I heard you can get a cheap 12v to 48v buck converter and use that to supply cell 16 on the BMS, then you can use the JK as a BMS with active balancer on a 4S 12v LiFePo battery. Feel like testing it with your 100AH cells?
I've got everything here already. The test will come soon...
@@OffGridGarageAustralia I believe you need to set the cell count to 4 - probably obvious but worth letting you know
The Ali link on your page for this jk bms goes to some weird foldable plastic cups...
That seems to be working fine for me on several devices:
off-grid-garage.com/battery-management-systems-bms/
Perhaps you could tie the inverter to your battery rack...
I thought about a mobile solution for this inverter. 😉
The problem is that it does not have the M.E.N. link which I need for the vehicle charger.
No under-temperature cut-off? Need that for Canadian setups. So close!
It has and it works. Video is coming very soon!
Does this bms remember the last settings made when the battery was disconnected and connected again? Or does it reset to factory settings?
Oh, no, it will remember all the settings, jeez, that would be terrible.
@@OffGridGarageAustralia Thank you...