Do this and you don't need a BMS đ
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- Äas pĆidĂĄn 3. 01. 2021
- FAQ: Do I need a BMS for my battery pack?
I'm showing you what happens when you charge a 4s battery bank without BMS and how you could get a full time job in balancing your batteries. It's unpaid though, so maybe it's a better idea to invest in a BMS?
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What an excellent explanation and demonstration of the function of a BMS. Thanks Andy.
Thanks Ben âșïž
Thank you, Thank you, Thank you!!! This was the best (and funniest) explanation I have heard on the BMS. You have a great way of teaching.
This is a great explaination especially to the begginner showing generally how a BMS works and why a BMS is important. It doesn't tackle the current limitations and temperature cutoff stuff so hopefully you can make a more advanced video tackling sizing a BMS and explain the other functions. Great content, sir.
Thanks, I will show more of these BMS bowel once we set one up. But, yeah, there is more to it, than just balancing and voltage protection.
Brilliant! I came here thinking I could avoid a BMS, but now you made it clear I need one (and entertaining at the same time)! I'm subscribing.
Thank you so much!
You can avoid a bms
A brilliant way to explain the importance of a BMS. Thank you.
You are welcome!
Thanks, Andy. This video was very clear about how a BMS works. You just topped up my knowledge. Have a nice day.
Thanks, you too!
Always learn more when I watch your videos! Thanks, J
Thanks so very much for the details and explaining the BMS.
First explanation of a BMS that made sense to me. Thanks!
What a great lesson. Thanks.
One of the better explanations of how/why a bms is needed, I would also imagine some capacity is lost when one cell gets to the maximum voltage and all the rest are somewhere below and in a large bank this could add up to a noticeable amount.
Thank you every good information
Excellent video, thank you for answering my questions!!!! đȘđđ
Happy to help! Thank you.
Very good informative video that easily explains why you need a BMS and how it works. Well done and thank you.
Great video! Love the dry humor!
You are wonderful. I am learning from your experience. Keep on.
Greetings from Saudi Arabia.
Thank you for your feedback!
This is the best and the funniest video I've seen today lol thanks a lot for the info.
Awesome||| thank you for the simple easy to understand explanation. I like how you used the lights as a load to explain what the bms does internally.
By the way I like the phrase âwhat the frogâ
Thanks a lot for your feedback, Bobby. Much appreciated.
Excellent demonstration and explanation, thank you so much
Well done, helped me understand easily.
Thank you very much. This is what I needed to know.
You are welcome!
Excellent video sir, many thanks for that information!
Glad it was helpful!
Great explanation! You can also top or bottom balance the cells as well. For using with off grid solar , most are now recommending top balancing. You can take your cells (In parallel) connect a DC Power Supply Variable 30V 10A to the bank and take them all up to 3.65v. Disconnect the cells and put them back in series and your done! Will Prowse has a great video on doing just this. Thanks for sharing!
Thank Dan. The pack is balancing for the last 4 days already. It takes a while with the small DC buck converter I'm using...
I think the purpose of top/bottom balancing is to get the cells prepared to be installed into a pack. It's a starting point only.
The idea (of top/bottom balancing, and NOT using a BMS) is to rely on the cells kind of bouncing around between the min and max voltage of the weakest cells, without using a BMS.
But this is flawed long term, because cell properties will change over time, and you don't want to have an outage of your system while you top/bottom balance again.
Doing a top/bottom balance at the beginning and then building your pack with a BMS, will give the BMS the best chance of doing it's job.
If you introduce an additional active balancer into the mix, this will enhance the BMS by keeping cells balanced from each other, not just burning power into heat to lower the high cells. This gives you the maximum power out of the pack, but it will cost the most.
Learned a lot by from this video! Thanks. Keep it up
Thank you!
When I finally got to your sick sense of humor, I couldnt help but laugh!
đ got you, ey?
Hey thanks you've got me on me guard now
Great video. Thankyou so much.
Thanks you, brilliant explanation for a BMS.
I love this video! Human BMS I love it. It shows you exactly why you should use a BMS unless you want to do all that unnessary manual work but it is an excellent way to teach BMS tech.
Very clear explanation
Another great video thank you for all the work you put into this chanel
Thanks a lot, John!
Thanks, you good teacher, for me.
Million thanks
You are welcome!
I used to let connected one of those cell meters on my scooter battery 7S 25.4V 60 Ah and after some charge/discharge cycles I had cell nr 1 and nr 2 with a significant lower voltage relative to the other 5 cells. Finally I realized that the meter to power the circuits uses the 2 first cells. Now I only connect the meter cable for some minutes to check the voltage and no more problems with the balance of the 7 series.
Thanks for your excellent videos.
PS: Just bought a JK BMS 150 Amp for my 15 kWh solar battery pack and I am very happy with it.
All the best from Portugal.đŹ
hi.... very clear "how to and why" video.. thank you!!!
You're welcome!
Great job explaining BMS technology
Perfect Explanation đ
Wow Great idea thanks
Great man, good explain. Thanks.
Glad it was helpful!
Just found your video. Fantastic explanation thankyou.
Love it!
Thanks!!
...beste ErklÀrung die ich gehört habe. Danke
I am still on the fence about a BMS and in the end I bought a 100amp BMS with a Bluetooth module. (24v system, 100AH LIFEPO4). The application displays the individual cell voltage and pretty much all parameters can be changed. In the end I decided for a BMS because of the low voltage cut-off since the inverter is not connected to the solar load controller. It also does cell balancing (only 2amps so it might take a while for a 280ah cell, haha) so that is a bonus. It handles 60amps draw for about 45 mins without a problem but we'll have to see in the long run if it keeps operating.
So far I am really impressed with it. And the phone app is kinda nice.
Great feedback, Peter. A BMS is a must! There is no way to keep these cells in balance without one. 2A balance current is a lot. Mine has only 250mA, I believe.
Probably the most significant content. This video should be modernized or at least remastered and re released again. Excellent!
Now tell us more about paralleling cells und one series bus voltage please.
âïžâ„ïžđ
Just ordered four cells off your link. Hope I get the same capacity tests as you did.
Thanks for your vids.
Thank you :)
@Dr SpaceMan
- Are you Off-Grid ?
@@vtorsi610 Nah I wish. Intend on using the pack to replace 3x200ah AGM batteries in a camper van.
what a cool video! Cheers
Thank you, Jonathan!
BATTERY MANAGEMENT SYSTEM OPERATOR nice one sir.
i really HATE clickbaits....but this one got a thumbs up for being the most instructive oneđ
Hahaha, thanks Alex. It's not real clickbait, right?
you got me there. position of BMS Operator taken :D
17.7 min waisted that I will never get back! Thanks buddy!
Bottom balancing will result in a ragged end voltage and a balanced discharged voltage. Usually the ragged charged voltage is not a terrible difference but when you remove the charge it will bleed off the top and usually be quite balanced at fully charge resting voltage. Takes a bit to bleed off the charge voltage to a stable resting voltage. Usually around 3.35 volts.
That cell that is filling faster is your low capacity cell in the bunch. If you charge to 3.5 volts and your low cell goes to 3.65 your pack is fine and let the charge bleed off to static voltage and I bet you will see 3.35 or maybe 3.4 volts per cell. So all have the same capacity at this point and will all be equally balanced at the bottom if you don't let it go below 2.5 volts. Monitoring the voltages is fine. If you have a cell that reaches 3.65 volts long before the others and there is still a bit of time before your termination voltage is reached and if that difference puts that one cell above like 3.8 volts then you need to swap in a better battery that has a similar capacity if you want to go BMS free.
nice! thanks!
Thanks!
sh*t can happen no matter how careful you are, so just use BMS. Ur battery are expensive
This is exactly what he is saying at the end of the clip. Obviously you have not watched to the end.
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Great video, the biggest issue I have is that most BMS devices have very limited current capabilities to discharge a cell and when you have high capacity cells like you show here (maybe 240Ah) they can struggle to bleed off the charge.
I thought the same but it's all about finding the right settings and over time even a small discharge and balancing will work. My BMS does only 0.2A balancing and it can balance all 16 280Ah cells down to 1-3mV deviation.
funny start... nice and informative vid (specially the $11 part and the frogs ":o)) ... thank you.
With your humanity glowing through the lens, gives hope to the world đ
Hahaha conclusion kinda took me by surprise, but made sense đ subbed
Thanks a lot and welcome on board. Just to explain how a balancer works, right?! đ
Love this video. đ
Redundancies are important.
Thank you! đ
On your cellmeter, push cell and mode button together and it's supposed to balance them. Not a BMS replacement but usefull anyway.
Thank you, sir.
Absolutely need a BMS :) For over-charge, over-discharge, and temp (hi/low) protection to cut-out a load. Balance as a feature of the BMS is good as well but not as important as the basic protections of a BMS.
Yes, I absolutely agree.
the best controller/bms i have found for lifepro4 is electrodacus as it monitors the single cells
Herlich sympathisch und kompetent erklĂ€rt...GrĂŒĂe aus Deutschland ^^
We have wall to wall sunshine today perfect for test, but temp will be about 30C
Great advice.
The bms operators job though, I tried that but I quit lol
Keep the economy going...you can probably get jobkeeper payments when the batteries are all balanced.
Without you Andy. I would be lost.
CHEERS MY UNMET FRIEND!
thanks for the video, nice and clear. And I like the frog.
Thanks for watching!
Great job đđđ”đ±đđ
There is a better solution to the unbalanced pack. Use an active balancer equalizer capacitors board which take charge from the highest cell and dump it in the lowest cell. It will keep them within 5mv. The solar charger control the charge and the inverter control the discharge. If you want more energy from the sun in cloudy days use solar panels in series with 150v capable mppt chargers.
Are you sure about the active balancer claim - can you point us to specifications that show this feature of active balancers vs non active BMS?
Personally, your comment and others making other ludicrous claims for active balancers reek of marketing hype.
@@BenMitro While I have no way of knowing whether the OP was acting in good faith, I do distinctly remember Julian Ilett having a few videos on active balancers as opposed to passive/bottom/top balancers, to balance his supercap/ultracap banks. The ones I saw _I believe_ were roughly 6 months-1 year ago.
Also vaguely remember a few videos on DIY Arduino projects accomplishing the same task, utilizing Digital-Analog Converters, for battery banks far in excess of typical series counts.
I'm not certain whether he was part of those as well, or in misremembering other CZcamsrs.
You know, I should probably examine this subject personally, if only to be more accurate regarding this topic in the future.
@@NightsReign Thanks NightsReign - I did watch Julian's coverage of active balancing, and I really like the idea of active balancing, but from what I've seen, power savings, and super accurate balancing are not founded in practical reality.
I mean many BMS balance at 30 or 100mA - and for a short stretch of time to adapt the cell to that of the pack, now a quick and dirty, order of magnitude calculation tells me that to discharge say 100mV at 100mA amounts to 1mW and that may be for, I don't know, an hour? of the total charge time of the cell.
With a 100AH cell, at 3.2V having 320Wh, to quibble over saving 1mWh sounds, like I mentioned, marketing hype rather than practical advice. This OP's comment sounded like active balancers are more precise "5mV" - what??? I don't normally react much to gibberish in comments, but this and other comments in this video really got under my skin. Again, thanks for responding, its great to discuss stuff with other commenter like yourself. When I'm wrong, I find out about it pretty quick and I do attempt to right my own wrongs (and there are many things I misunderstand or simply don't understand).
@@BenMitro The other issue with only using an active balancer instead of a bms is that it lacks all the other safety features a proper bms provides, such as over charging, over discharging, over or under temperatures, too much charging current, too much discharging current, etc. If the balancer fails you'll only know if you have some other system monitoring it, if your charger fails and puts out too much voltage you'll only know when your pack fails, generally if your bms fails it simply disconnects the pack so long as its a decent quality one. So while an active balancer might help when used with a bms to handle larger swings in voltage than the BMS can do itself, it's just not a good solution all by itself because it leaves multiple ways for the batteries to be damaged.
@@BenMitroif I were not sure, I'll not be guiding people in the wrong direction. This one is 2A but for one of my 280ah 48v pack I am using 10A balancer to bring the pack within 5mv. czcams.com/video/rQgOet7AH0I/video.html. And of course these balancers aren't long lasting as BMS but you can get more power out of the pack. As for charging I use several makeskyblue which I can adjust my top voltage to 54v and the inverters cut off point is adjusted to 48v for the bottom limit.
Greetings from Sweden. Great Chanel đđ
Thanks and welcome
@DIY Projects you have to come in South of Europe.
I live in Sicily island and with a 5.4kW PV, yesterday (04 january 2021) it made 16kWh
@DIY Projects Yeah only sustainable during winter months would be hydrogen during winter from solar panels on summer, but expensive.
Nice đ
Hilarious! Made my day! I'll use a BMS to skip the BS! Thank you for posting!
Love your videos and even more love your off grid garage! Question, how can you test a battery pack managed by a BMS that does not have an app? or how do you know if the cheap BMS actually do anything? The ones with the apps are way too expensive to use on small 12v packs, fine on a large system but small individual systems makes things uneconomical.
A superb example of why you need a bms!
Lol, great vid man! That cell checker if you hold down the right button it will go into balancer mode if you want to balance them while charging. Pretty handy cheap device. Another option out there if you want to get it to work a little more efficiently is to get an active balancer they take the voltage on the high cell and transfer it to the low cell instead of wasting the energy using a load resistor. Fairly cheap the only caveat is you need to have your own low voltage shutoff. I prefer a regular BMS with my smaller battery banks but as you go bigger the BMS can't handle the amperage. So options with a larger bank are to use a regular BMS and have it control a relay using the output wires. My setup I went with an active cell balancer and a low-voltage cut-off relay, Lots of options out there got to choose what works best for you.
Thanks for the feedback. If I hold down the right button it goes into discharge mode...
@@OffGridGarageAustralia I wonder if it's simply a difference of models from the same manufacturer, or they mistook yours as an altogether different device?
Sorry yes different than mine. They look the similar but mine is a 5-in-1 Cell Meter. Made by Tenergy.
When you have only a 4 cell battery pack, it is easy to charging the cells individually, at your desired voltage and current to recharge them up again!! I first charge mine, as' a full battery, till almost reaches its limits, then finish off, just charging the individual cells to their full potential, thus keeping the cells balanced and ready for a further discharge. Regards George.
It would be interesting if you could do a comparison with two identical panels out in Open Sky both on sunny and cloudy days one with an mppt charge controller and the other one directly connected to the battery and measure how many kilowatt hours each system produces.
I love the frog đž
Lucky me, I bought the same bms. For 75 euro. Now I can watch your entertaining tutorial and not have to figure out the kinks.
Got a new job position today as a "Battery Management System Operator"!
Hahaha, welcome to the team then đ
Subscribed..like the way he says 12volt
I'm using 12V Lifepo4 7Ah batteries that are designed for use in a UPS. They have built-in BMS which keeps the cells balanced and also provide over, under and short circuit protection!
I have them wired up in series for 48V which also needed some sort of balancing so what I did was to use an MPPT charge controller for each 12V battery, that way each battery pack will be charged separately as the charge controller is adjustable for the maximum voltage!
I have tried the same thing with 18650 lithium ion batteries in series, I have been charging them to 4.2V each at the same time, some stop charging earlier and some later but they never go over and they are automatically balanced!
Not sure if you understand what I have done, picture it as a series of car batteries, now take a few 240V car battery chargers and connect one charger to each battery and turn on all the chargers! They might be all in series but because they are being charged individually, they will always be in balance and you never have to check on them.
The MPPT charge controller that I'm using is from eBay, it's just a circuit board with no enclosure! I think that they cost $10AU with $5 shipping, they are rated for 100W so for me that means a total of 400W of charging, they can also be paralleled for twice the current output and they have a potentiometer to tune it exactly to the solar panel that you are using for maximum power point tracking! And they track extremely fast! I have had others where I would wonder what they were doing because they were so slow! You see the sunshine come out and it's like it's thinking about what it's doing! No so with this little thing! As soon as there's ambient light first thing in the morning, it's already on and trying to charge...
Higher voltage is so much more efficient, with the 48V system, I just had to use 4 12V Led Down lights per room which meant that I didn't have to use thick cables to carry the current to the lights...
And because my batteries are small and in their standard UPS style case, they are cheap if I need to get more storage capacity! They cost $70AU each as opposed to $500 each if I chose to go with higher capacity from the beginning! And because I'm using multiple smaller batteries, I can charge and discharge at higher current without causing them to heat up and becoming damaged so basically if I could get away with just four $500 batteries to cover everything that I need, I would prefer to get 8 at half the size, you can charge them twice as fast...
HAHA I love this, I came here ready to flame this video, but the mature viewer in me watched till the end. When I was first learning lifePo4 batteries, one of the first things I did was balance the batteries and then call it a day.
Long story short, on a sunny day, the 100 AH batteries in a 4s config took a 40 amp charge and completely bulged out 2 out of the 4 batteries. I wanted to make sure someone wasn't spreading miss information, and you are doing an excellent job of helping teach why in deed you actually need one.
Another good mention would be an active one (BMS) that moves power between cells, vs a passive one that burns off the higher cells as heat.
I suppose a battery operator could use alligator clips to connect the high and low cells :)
Great Job!
So true, a BMS is necessary. However people should be very wary that not all BMS's do the Balancing feature. Some will just disconnect the cell if it goes outside its parameters. Separate Balancer/Equaliser boards are available to add onto battery packs with a BMS not including this feature.
Super Lifepo4 very goodđđ€đ€
that is very nice
Thank you.
grazzie molto istruttivo.
Good job sir love from India
Thank You Andy for showing us this cell meter 8. Its would be nice to have a independent control monitor beside the BMS, ideal for people like me who suffer from cell phone allergies ; )
Some BMS now come with a display where you can check on the voltages of all cells...
@@OffGridGarageAustralia Thank you, yes there are "overwhelming fancy looking" displays for my Jikong BMS, but they cost 6AUD more and they are less convenient to operate. The Cellmeter8 costs less than 10AUD here on Lazada. It fits perfect for my 24V battery and I get some redundancy this way for more security : )
sorry sir, if there is a weak cell in the row it will be the first which reaches the max. voltage and will also be the first which is at the lowest value decharging the battery. Only cutting off the process will help to rescue the weak cell not balancing.
You have so many trees for poly or mono solar panels. Try thin film solar panels for power in all types of conditions, even partial shading
Thank You for posting very useful information, and this leads to my power question on this subject. When I bring in a solar panel charge controller, how do I assure that the power controller is controlled by the BMS and the BMS dominates the charging process.
I would love to see the BMS and the tester together so we can see it balance charge
You will very soon...
This is EXACTLY WHY a BMS was created.
i was thinking that the best connnection for batteries is in packs of four , a parallel of two in series . and that forms a block , for a scale up, next you go to four blocks .
the reason behind this is to keep a uniform charge and discharge of the batteries ,without a single battery or more ,goes between two other batteries .
and i think the measuring points for calculating where an error in the uniformity exists , are less .
You could always keep the 3.6V bank in parallel and use some kind of inverter to generate the 13.6V to 48V you need for your purpose.
Uhm, probably not, the currents would be BIG. I mean really big!!!
But the distances could be very short. I think I may go this route.
You can use an active balancer to avoid cell drifts... I do it so an it works perfect.
Post a URL link and price of your Active Balancer ...
Brilliant! Thanks Andy.
Could you perhaps recommend such a solution for lead acid stationary batteries ? as in connected to a UPS?
hilarious end , where can I apply for that position ?
I noticed that you refered to the cells as spreading apart. I assume that indicates that they are puffing up or expanding. Some sources say that explanding and contracting is not a good thing because that could lead the anode-separator-cathode combinations to delaminating. The same sources say that puting the cells in compression will eliminate any potential problems related to the cells expanding and contracting.
I also understand that expanding could also be the result of overcharging or mistreatment at one time or another during a cells life as you did say at one time during the video. I assume that these batteries took some time to reach you. Could they have been in a overheated shipping container for some time?
Hello from America another great video Andy thank you what BMS are you using and what BMS would you recommend I need Bluetooth fully programmable and at least 300 amps for 4s 310 amp cells thank you for sharing your ideas and time with us keep up the good work and stay safe
Adore your frog, sounds like he is well trained.