The pulse 2A balancing is as per design and it is not safe to have continuous balancing esp in such higher current. The BMS balancer is designed to sense the voltage accurately by dropping balance current. This is to prevent overcharging and discharging of the cells by the balancer itself. Voltage reading over the small balance leads will be inaccurate if the current is not dropped to 0. Hope you understand the function.
good test but this has to be like that, you can not draw / send current and also sense the voltage correctly at the same time. It would need separate leads for that or to drop power to do it
Hi there. Firstly, your video has been a great for getting me to build my own battery pack. I had my pack running for several months with the JK BMS you are using in this video. Recently, I have an alarm shown on the app relating to this BMS. I switched the BMS off fixed the problem and discovered that I could not turn it back on. I tried using the 5V approach and also using the LCD display. Nothing happened, I noticed also that the cycle count before turning off was 77. In the past, I was able to switch it on and off but now it will not turn on at all. Have you experienced this? I am open to any suggestions you might have.
BMS's momentarily stop balancing current to make cell voltage sensing without influence of small gauge sense wires voltage drop due to balancing current.
My experience of 3 months,24 hours a day is that it works, but it is really slow,useless on 100+ AmpHour batteries while they are charging or discharging; when one of them wants to drift to + or- 0.300 or 0.400 V, it just can´t cope; if they are off, it works ok, but then it will hardly be needed; Mine are not matched, but of course the best way is to have closely matched cells from factory; what i do is, i paralleled the 8 mismatched,cheap, 200Ah cells with 8 excellent ones of 60Ah,the best (someone gave me them,used from 2014, Winston?..factory matched with serial numbers!!) 2 by 2 ,2P8S, and the 60Ah ones keep the big ones in check; 1 BMS, 8S, only,all have monitoring wires of 1.5 mm2.
@@SolarEngineering ok thanks. its amazing how its rated for 200A continuous but the wiring can't handle it. The JKs are really good BMS in terms of features and the balancing current. If they can only utiilize the proper rated cables, this BMS would be unbeatable.
@@hendersonsobers396 the cables are able to handle it. The good thing is they have threaded in and outputs which you can make your own thicker cables even with 35mm and 70 mm terminal cables which fit. Andy in Off-grid garage has tested this. This a good video to explain how the BMS works, but the reason why it works with pulses, has to do with reading and pushing power in between readings, but the assumption is correct, not a continuous 2 amp balance.
@@SolarEngineering If this helps, i have that BMS with the bluetooth, and at 80 Amps steady for 1 hour at 25ºC ambient, on just ONE wire( that is all i need,and makes for an easier installation) it works fine,stays cool by itself,no cooling,no fan,no water spray; it also has the best silicone jacket quality, and best extremely fine tinned wires, hundreds of them; ( rated for over 200ºC,the manual says); so far,it works like a champ ,3 months on, but i never push more than 80Amps, and usually 30 Amps only all the time.
4 AWG wire is recommended for current draws of 150 amps - 250 amps @ 13.5v @ 4-7 feet. The JK BMS used dual 7 AWG wire @ 1/2 ft. This is 2x13mm2 = 26mm2. This is actually thicker than 4 AWG (25mm2). So, can 1/2 ft of dual 7 AWG copper wire handle 200 A? Answer is YES
Come on get real. It isn't possible to move 2 amps continuous. The process is to charge a capacitor from the chosen high cell and then when the capacitor is charged, discharge the energy into the chosen low cell. The active balancer you already have does exactly the same process. It works fine even with 320ah cells.
@@SolarEngineering Not an opinion matey, its physics. If you have access to an oscilloscope, monitor the charge current profile on one channel and the discharge current profile on the other. Be careful with the common ground though, you could short out several cells. Using a capacitor to transfer charge from one place in a series circuit to another is a handy, efficient and understandable methodology. Remember the cells must remain isolated from each other, the capacitor does that effectively and flexibly. Imagine cell 16 is the high one at instant"a" while cell 5 is the lowest, current flows from cell 16 into the transfer capacitor to create charge at the classical exponentially reducing wave shape. Once the capacitor is charged the terminals are switched across cell 5 until discharged. The processor then polls for the instantaneously highest cell and recharges the capacitor, polls for the lowest cell and discharges into that cell, ad infinitum. Any balance device that draws continuous current is just burning the highest charge off in a resistor, which is why this type are limited to milliamps. Remember in the physical world (unlike the political world) "alternative facts" can't exist. Opinions without facts are at best a guess or maybe a wish. Facts must be measured or demonstrated (and attempts made to disprove them).
@@mikenewman4078 I just got the jk 150 amp version I have been watching off grid solar garage he has vid showing Charging from more than one low cell at a time randomly just saying without monitoring all the cells he is just on one.
@@mikenewman4078 i think you may be missing something: it is NOT possible to take energy, ---Ah, from cell 2 at 3.222 volts, store it in a cap, and then transfer it to cell 1 at 3.202 volts, in .25 seconds; it's a neat trick that they do,do you know how it's done edit: i think i do, just checking it now
Hi....How can I synchronize the JK bms so that it gives the correct reading of the SOC? I was making some parameter changes and when I clicked "ok" I changed the SOC to a lower one (100% to 76%), the battery was already at 100% (54.4V). .I need help
In the installation of my JK BMS I cut some of the cables that go to the batteries to avoid having to coil them. I wonder if JK BMS tests each wire and enters a different resistance for each without user intervention?
Can you please let me know how did you connect the black cables marked P-? And why are there 2 blue cables marked B-? One is not enough?Thanks for the reply
P- and B- paralleled. You need to use all of them to distribute load from BMS equally. B- connected to battery negative. P- to load (aka inverter/charger) negative
hm, installation off application is another topic, check your phone.. I noticed that LED is solid when BMS not balancing any cells. Also BMS charging activated, make sure BMS is active.
Have you triggered the BMS with a voltage at least 4V higher than the battery voltage? Off Grid Garage CZcams channel had the same problem.. it is not mentioned in the instructions that came with the BMS. Once he had triggered it , the BMS worked well and the light started flashing... See his first video about the JK BMS.
Just tried this one on a new pack to charge it as 1 cell wanted to run but it won't pear with my phone since I changed the password ever have an issue with yours? Don't know if I should buy another I don't need $400 paperweights (200 ea)
Thank you for uploading this video, while I was looking for the best BMS model I came across your video, and it game me so much insight. Even the comments linked was very informative. Finally I ended up getting a 150A Continus 2 A Active balance 24s JK BMS. Here's a video of making my 48V lifepo4 battery pack - czcams.com/video/13itWthR9Co/video.html
JK over Dally. The balancing of the dally ends when the battery is charged, even if the cells are not balanced. The JK BMS can start balancing when battery is mostly changed and can keep balancing after the battery is fully charged (to deal with very large battery banks.)
Take max load current or charge current and multiple by 2 (because cheap Chinese BMSs usually overrated). I'm pulling about 90A Max from my battery bank with this BMS, so far works great.
@@MyGoogleCZcams yeah, unfortunately, it's soldered to BMS, and it's going to be hard to fit a bigger awg there. It works fine in my setup since I published this video. (not pushing more than 100A trough bms)
@@SolarEngineering i watched offgrid do a review on these bms's and his let smoke out at 200 amp. Im considering buying 2 for 2, 4s batteries and want to be sure they are ok.
@@SolarEngineering of course,you are right, it works only half of the time; but what about the ones that only say 500mA, or 1 amp? you need to divide that by 2,also,or not?
@@SolarEngineering Correct, and it only balances one cell versus the other balancers doing multiple cells so its even slower than half. But it still works good enough, well done JK!
It needs to stop balance and check and read the voltage if it should continue to balance or not since it is using the same cable to read the voltage in mV and transfer the power. If you check other litium presition chargers with one small cable per cell you will notice this is common. But it is good to know it will only transfer energy from and to a pair of cells at a time. From what I can see there is no claim that it a 2A continiuos balansing. That would require double or much thicker cables per cell. I wounder why this is a problem for you other then you did not expect this and only read the title with 2A.
@@johthe wouldn't that be the same as having a 150amp bms, that cannot do 150 amps continuesly but only a few seconds at most? I guess this is a 2A balancer that works by design, which is good but people get another idea with 2A; tbh in my opinion it could be 1A I'm not complaining just recently ordered mine.
The pulse 2A balancing is as per design and it is not safe to have continuous balancing esp in such higher current. The BMS balancer is designed to sense the voltage accurately by dropping balance current. This is to prevent overcharging and discharging of the cells by the balancer itself. Voltage reading over the small balance leads will be inaccurate if the current is not dropped to 0. Hope you understand the function.
good test but this has to be like that, you can not draw / send current and also sense the voltage correctly at the same time. It would need separate leads for that or to drop power to do it
Yes would definitely like to see more testing on this jk bms, just got one myself and I like it so far
definitely will do.
Hi there. Firstly, your video has been a great for getting me to build my own battery pack. I had my pack running for several months with the JK BMS you are using in this video. Recently, I have an alarm shown on the app relating to this BMS. I switched the BMS off fixed the problem and discovered that I could not turn it back on. I tried using the 5V approach and also using the LCD display. Nothing happened, I noticed also that the cycle count before turning off was 77. In the past, I was able to switch it on and off but now it will not turn on at all. Have you experienced this? I am open to any suggestions you might have.
BMS's momentarily stop balancing current to make cell voltage sensing without influence of small gauge sense wires voltage drop due to balancing current.
of course,makes sense; and 2 amps steady would be too much.
Good to know the applied/discharged current is not constant but is pulsed. Do all BMS operate in this manner? Or only high current models?
It will pull 2a from a cell but it only does that 40% of the time. But it works very well.
My experience of 3 months,24 hours a day is that it works, but it is really slow,useless on 100+ AmpHour batteries while they are charging or discharging; when one of them wants to drift to + or- 0.300 or 0.400 V, it just can´t cope; if they are off, it works ok, but then it will hardly be needed;
Mine are not matched, but of course the best way is to have closely matched cells from factory; what i do is, i paralleled the 8 mismatched,cheap, 200Ah cells with 8 excellent ones of 60Ah,the best (someone gave me them,used from 2014, Winston?..factory matched with serial numbers!!) 2 by 2 ,2P8S, and the 60Ah ones keep the big ones in check; 1 BMS, 8S, only,all have monitoring wires of 1.5 mm2.
I've just ordered two of the 2 Amp bms. I hope they do good on my 24 volt configuration
it's a good balancer, make sure you crimp connectors for each balancer (do not combine 2 wires under 1 connector)
Excellent stuff!!Does jk BMS connect with growatt spf 5000es can bus or rs485 with parallel inverters and many different battery packs?
I don't know about that.
I looking for same answer. Did someone try this comunication please ?
I just bought a Jk BMS and it looks like this one. Why are there 2 B- leads? Do I tie them to the battery negative together or save one?
Really good video. Are those 2 cables on each side of the BMS even capable of handling 200A sustained?
these wires are not rated for 200A for sure, I'm pushing 90A through BMS and so far it works fine.
@@SolarEngineering ok thanks. its amazing how its rated for 200A continuous but the wiring can't handle it. The JKs are really good BMS in terms of features and the balancing current. If they can only utiilize the proper rated cables, this BMS would be unbeatable.
@@hendersonsobers396 the cables are able to handle it. The good thing is they have threaded in and outputs which you can make your own thicker cables even with 35mm and 70 mm terminal cables which fit. Andy in Off-grid garage has tested this.
This a good video to explain how the BMS works, but the reason why it works with pulses, has to do with reading and pushing power in between readings, but the assumption is correct, not a continuous 2 amp balance.
@@SolarEngineering If this helps, i have that BMS with the bluetooth, and at 80 Amps steady for 1 hour at 25ºC ambient, on just ONE wire( that is all i need,and makes for an easier installation) it works fine,stays cool by itself,no cooling,no fan,no water spray; it also has the best silicone jacket quality, and best extremely fine tinned wires, hundreds of them; ( rated for over 200ºC,the manual says); so far,it works like a champ ,3 months on, but i never push more than 80Amps, and usually 30 Amps only all the time.
4 AWG wire is recommended for current draws of 150 amps - 250 amps @ 13.5v @ 4-7 feet.
The JK BMS used dual 7 AWG wire @ 1/2 ft. This is 2x13mm2 = 26mm2. This is actually thicker than 4 AWG (25mm2).
So, can 1/2 ft of dual 7 AWG copper wire handle 200 A?
Answer is YES
Come on get real. It isn't possible to move 2 amps continuous. The process is to charge a capacitor from the chosen high cell and then when the capacitor is charged, discharge the energy into the chosen low cell. The active balancer you already have does exactly the same process.
It works fine even with 320ah cells.
I'm on max level of realism. I see you opinion, mine slightly different.
@@SolarEngineering Not an opinion matey, its physics.
If you have access to an oscilloscope, monitor the charge current profile on one channel and the discharge current profile on the other. Be careful with the common ground though, you could short out several cells.
Using a capacitor to transfer charge from one place in a series circuit to another is a handy, efficient and understandable methodology.
Remember the cells must remain isolated from each other, the capacitor does that effectively and flexibly.
Imagine cell 16 is the high one at instant"a" while cell 5 is the lowest, current flows from cell 16 into the transfer capacitor to create charge at the classical exponentially reducing wave shape. Once the capacitor is charged the terminals are switched across cell 5 until discharged. The processor then polls for the instantaneously highest cell and recharges the capacitor, polls for the lowest cell and discharges into that cell, ad infinitum.
Any balance device that draws continuous current is just burning the highest charge off in a resistor, which is why this type are limited to milliamps.
Remember in the physical world (unlike the political world) "alternative facts" can't exist. Opinions without facts are at best a guess or maybe a wish. Facts must be measured or demonstrated (and attempts made to disprove them).
@@mikenewman4078 I just got the jk 150 amp version I have been watching off grid solar garage he has vid showing Charging from more than one low cell at a time randomly just saying without monitoring all the cells he is just on one.
@@mikenewman4078 i think you may be missing something: it is NOT possible to take energy, ---Ah, from cell 2 at 3.222 volts, store it in a cap, and then transfer it to cell 1 at 3.202 volts, in .25 seconds; it's a neat trick that they do,do you know how it's done
edit: i think i do, just checking it now
@@josepeixoto3384 what's the trick? 👀
Hi....How can I synchronize the JK bms so that it gives the correct reading of the SOC? I was making some parameter changes and when I clicked "ok" I changed the SOC to a lower one (100% to 76%), the battery was already at 100% (54.4V). .I need help
In the installation of my JK BMS I cut some of the cables that go to the batteries to avoid having to coil them. I wonder if JK BMS tests each wire and enters a different resistance for each without user intervention?
There is a screen on the app that shows the resistance of each wire. I don’t know if it uses that info or just displays it
Can you please let me know how did you connect the black cables marked P-? And why are there 2 blue cables marked B-? One is not enough?Thanks for the reply
P- and B- paralleled. You need to use all of them to distribute load from BMS equally.
B- connected to battery negative.
P- to load (aka inverter/charger) negative
Hi. I have such a Bms, and I have a problem that the LED does not flash.
How can I make it happen? Can I install JK BMS?
Thanks
do you mean BMS doesn't work at all or just LED doesn't blink?
@@SolarEngineering Stop blinking!
And I don't think I can install the application to start Bms control
hm, installation off application is another topic, check your phone..
I noticed that LED is solid when BMS not balancing any cells.
Also BMS charging activated, make sure BMS is active.
Have you triggered the BMS with a voltage at least 4V higher than the battery voltage? Off Grid Garage CZcams channel had the same problem.. it is not mentioned in the instructions that came with the BMS. Once he had triggered it , the BMS worked well and the light started flashing... See his first video about the JK BMS.
Can amp be increased by increasing mosfet in 60amp jk bms, because the space of mosfet in pcb is empty
I'm not sure.
Just tried this one on a new pack to charge it as 1 cell wanted to run but it won't pear with my phone since I changed the password ever have an issue with yours? Don't know if I should buy another I don't need $400 paperweights (200 ea)
strange, do you have red led on? do you hear BMS beeping when you power it?
Can it communicate with Inverters like Growatt, GoodWe, Deye ....?
I don't know that.
Thank you for uploading this video, while I was looking for the best BMS model I came across your video, and it game me so much insight. Even the comments linked was very informative. Finally I ended up getting a 150A Continus 2 A Active balance 24s JK BMS. Here's a video of making my 48V lifepo4 battery pack - czcams.com/video/13itWthR9Co/video.html
Your not using the Chargery BMS anymore?
I burned it by accident, don't want to go back to chargery.
Would you recommend this or daly BMS?
I haven't use it yet for continuous period. Can provide my opinion after month of use.
I don't want to come back to Chargery BMS for sure.
@@SolarEngineering waiting for a review video! Also, your video presenting is very good. Great videos, keep it up!
@@gytax01 thanks for the feedback, appreciate it.
JK over Dally.
The balancing of the dally ends when the battery is charged, even if the cells are not balanced. The JK BMS can start balancing when battery is mostly changed and can keep balancing after the battery is fully charged (to deal with very large battery banks.)
Hi,if i have this bms with active balancer should i put another activ balancer?
This BMS has a builtin balancer.
@@SolarEngineering Thanks.
some voltage drop from inside and outside bms?
will test when it's going to be attached to bigger battery.
is that enough to charge 280A 24V battery? (8 cells)
by specs it can charge upto 200A, I personally didn't exceed 100A.
How do you calculate the size BMS to purchase?
Take max load current or charge current and multiple by 2 (because cheap Chinese BMSs usually overrated).
I'm pulling about 90A Max from my battery bank with this BMS, so far works great.
@@SolarEngineering Thanks for your reply.
Why don't they sell a version with threaded holes?
good question, idk
@@SolarEngineering it looks like 8awg....I would rather do my own wires.
@@MyGoogleCZcams yeah, unfortunately, it's soldered to BMS, and it's going to be hard to fit a bigger awg there.
It works fine in my setup since I published this video. (not pushing more than 100A trough bms)
@@SolarEngineering How did you bind on to the supplied wires?
@@MyGoogleCZcams crimped 2 wires under one lug.
These two are the same thing, the BMS has an extra switch inside.
Do this with the qucc bms please!
didn't get your question.
Yes👍🔋⚡ 💡
So, is it junk ?
no, it's working in my 23kWh battery bank. I'm pulling/pushing about 100A, and so far works great.
@@SolarEngineering i watched offgrid do a review on these bms's and his let smoke out at 200 amp. Im considering buying 2 for 2, 4s batteries and want to be sure they are ok.
@@karldingbat I haven't pushed 200A, even wires soldered to BMS are not rated to 200A. So I derated BMS to 100A.
how to reset
cut balancing amperege in half?? what kind of amature talk is that. unbelieveble.
I feel like "1A constant active balancing" will be more correct description of bms/balancer.
@@SolarEngineering of course,you are right, it works only half of the time; but what about the ones that only say 500mA, or 1 amp? you need to divide that by 2,also,or not?
@@josepeixoto3384 yes, it will work same way, so need to divide by 2.
@@SolarEngineering Correct, and it only balances one cell versus the other balancers doing multiple cells so its even slower than half. But it still works good enough, well done JK!
That's not good
Its operating just like it was designed to do.
but not as advertised.
It needs to stop balance and check and read the voltage if it should continue to balance or not since it is using the same cable to read the voltage in mV and transfer the power. If you check other litium presition chargers with one small cable per cell you will notice this is common. But it is good to know it will only transfer energy from and to a pair of cells at a time. From what I can see there is no claim that it a 2A continiuos balansing. That would require double or much thicker cables per cell. I wounder why this is a problem for you other then you did not expect this and only read the title with 2A.
@@johthe wouldn't that be the same as having a 150amp bms, that cannot do 150 amps continuesly but only a few seconds at most? I guess this is a 2A balancer that works by design, which is good but people get another idea with 2A; tbh in my opinion it could be 1A I'm not complaining just recently ordered mine.
Yes👍🔋⚡ 💡