Gobelpower Battery Active Balancer Test. Better with or without?

[@Klostergeist007]

Sometimes I think your life’s purpose is to do the tests none of us have the time and resources for. Thanks a bunch

[@OffGridGarageAustralia]

Thank you. Yeah, im interested in this stuff and would do the testing anyway. Luckily, I can share it here with you.

[@Dan-LS]

We love it 😅 Thank you! ✌🏻

[@upnorthandpersonal]

I'm now about to enter my 5th year with 280Ah EVE cells bought in 2019. Active balancer only active over 3.45V, no issues with balance what so ever - and they are used far from full over winter. In spring, they go back to 100% after 6 months of winter, without any meaningful delta between the cells. I use a JK with 0.6A balancing current without issues what so ever, just turn the balancer on at or above 3.45V and you're set.

[@habana7638]

Same here for the last three years, balancing Eve 280Ah 24V smal system with SBMS0 max 200mA, nine months a year offgrid, delta now 6 mV, never had any problem, use it for what it's meant to be?.

[@TrevorFraserAU]

Agreed

[@farhatmirza7736]

What about capacity now after 5 years?

[@upnorthandpersonal]

@@farhatmirza7736 I capacity tested one of the cells last year: 267Ah (out of the original 280Ah measured when I bought them). That's a cell made in 2018, so 5 years old when I tested that, and I doubt they were new or 'grade A' or whatever. Things were a bit shady back then. So about 1% capacity loss per year assuming it's linear - which appears in line with stated calendar aging in the literature.

[@jws3925]

Same results as we hypothesized. Repeated results makes the outcome a very reliable outcome. Keeping the active balancer on 24/7 is not a good idea and will destroy the top balancing of the pack. Excellent experimental design with repeatable results.

[@ToddDesiato]

Thank you, Andy! It's so nice to see someone use empirical evidence to make a point, not just offer an opinion.

[@abid583ind]

The imbalance in the cells occurs when the charging current is close to the full charging current of the cells, the runaways reach the disconnect peak fast and leave the rest in a voltage that is still not the full charge voltage

[@tomassliauteris884]

I agree with Andy. I do the same 3.45V on. And all works perfectly.

[@clarencewiles963]

Thanks for the walkthrough. We live in a world of voltage ⚡️

[@TrevorFraserAU]

I can confirm even starting to balance at 3.42 and it does work as well as only starting at 3.45 so my test results mirrors your test results.

[@jackoneil3933]

Excellent and important work here Andy! And a valuable and timeless reference for all to benefit from. Much appreciated!

[@jackoneil3933]

@@jasonbroom7147 I totally disagree. For people who have a genuine interest. I've worked with battery systems for decades and found it worthwhile and informative. And even if you didn't find it interesting, it seems Andy provided an opportunity to express resentment and judgment, which makes most of us feel just a little bet better about our situation.

[@junkerzn7312]

These are great comprehensive tests! A lot of work, for sure, but you are getting really definitive results out of these experiments. Notice how VoltDiff becomes so squirrelly at the bottom during the discharge? It's jumping all over the place. That is very illustrative of just how confused a balancer could get were it to attempt to work the cells based on those readings.

[@OffGridGarageAustralia]

I also have forgotten to mention, that the balancer was still on at around 2.8V. I had a quick look inside the battery and the light was still on. I always thought they turn off below 3V to prevent chaos below that voltage.

[@cooperhunter228]

If you set the active balancer to a charge level of 3.4v, there will never be problems with balancing. I had a problem with battery equalization from JK BMS when I used factory settings and balancing starting from 3v

[@loucinci3922]

Very cool - especially the moon voltage!! Thanks for sharing

[@FutureSystem738]

Thanks Andy, great stuff as always! I think you’ve nailed it, (and have explained it perfectly.) I’m really happy with my JK BMS, which usually keeps things very well under control. 🤔

[@alfredrein699]

I have the same result here. I only do a top balancing on my 32kWh battery every 3 months, that's enough. For this I have the 15A balancer from Neey. This works fine.

[@georgefairlie2547]

Great work Andy. Happy spring charging. What are you going to do with all your excess summer power?

[@nigelshindler6334]

Hi Andy, what a great and informative video yet again! Your patience is astonishing. Question: i have seen an active balancer that is set to only activate when voltage difference between cells reaches 100mv, and deactivates once it reaches 30mv. Do you think this would be an alternative solution to the problem of the continuous balancing? I think that trying to keep the difference below 30mv is a bit pointless anyway.

[@AhLoui]

When I was starting with learning about LiFePO4-batteries, I also thought that earlier start with balancing would be better. But then I came to the same conclusion. Great that you have done all these tests, Andy. Thanks for that!!

[@OffGridGarageAustralia]

Thank you. I have this topic again in my next video. Many people are still doing it wrong and set the balance voltage incorrect. It's very easy to do and gets us good results.

[@dougbaskins9380]

Excellent review. I tried to buy one for $2660. They wanted over $3000 shipping cost. Andy, watch for Rip-Offs. They one you tested cost about $4000.

[@kamolhengkiatisak1527]

Why not test active balancer ON once a week for one day? It might be the optimum option.

[@guy7gsa]

Hi Andy I have some old 16S and 15S lithium ion cells, the only reason I use an active balancer all the time is because they old and have a very high delta voltage. I agree with you no need to active balancer for new cells.

[@ericblackburn9829]

I would suggest a voltage sensitive relay to turn on and off your balancer, even for unmatched cells. Even if they are old and unmatched in capacity the difference in resistance of each of the cells should result in pretty close top balance at the top of the charge.

[@tigiewig]

Danke, thanks for all the testing and explanations , really helps to get an understanding of solar charging .. (😀wonder how many under 25 people watch the channel )

[@Konrad016pl]

Ja . A mam 37 lat . Magazynowanie energi to bardzo ciekawy temat . Niestety tylko dla małej grupy ludzi.

[@nainabla]

I am confident that the cells get unbalanced when the active balancer is always on because of the difference in the capacity of the cells. Note that the 202mv deviation in the cells at the top voltage is only 1% of a difference in the SOC.

[@jasonbroom7147]

Exactly! Which makes this entire line of videos on cell balancing a big waste of Andy's time, although it's his time to waste. What he never mentions is how completely irrelevant these deviations are. Look at the cell voltages at 95% and again at their resting state, after being charged...not enough deviation to even caus the 1% difference in capacity you mentioned! This entire video was pointless.

[@SenatorPerry]

That is, in essence, why this topic continues to confound me. The balancer opens a pathway to the capacitors and charges all the capacitors in a parallel path until they are balanced. Then it opens a path to discharge the capacitors into the cells with the cell with the lowest voltage receiving the bulk of the current due to the voltage delta being the highest. Repeat over and over... As the voltage delta decreases the current decreases. This is essentially setting the batteries in parallel as a top or bottom balance does on a repeated basis, just all within the confines of a PCB and small doses. To continue to focus on the results without understanding why is what causes this topic to live on. If we recreated the process the active balancer uses with some small batteries and alligator clips I am not sure we would have the same results (ruined top balance). I keep an active balancer on all the time on one of my batteries, but I have a 6S, 12P setup that is about 15.6 kWh and the draw is at a max 300 watts and typically 100 watts. It has run for years without issue constantly fighting a battery that should have been retired years ago. I wonder if the truth is that the fault is in high series count batteries (16s) leading to some design weakness.

[@SolAce-nw2hf]

Nice test. Would it be difficult to test what such a balancer could achieve with some mismatched cells in a somewhat slower charge and discharge? If it can get as many somewhat acceptable cycles out of a mix of reused cells before getting rid of them, that would be a good thing for the environment. As long as the good cells can keep up with draining of the bad cells, it may just work longer. Very nice that your solar cells maybe could power a night light, using them as lunar cells,

[@lucaskock-to1jw]

Hi, Balancer only balances temporarily. It can balance the battery every time, but it will not fix the problem batteries in your battery pack. Only if you replace them. Thank you, and keep testing. I have all the time of the world.

[@micropower8]

Timestamp 30:40 - Energy loss: You have all of the energy lost if you balance the voltage with resistors or with capacitors, look at the schematic of this devices. In both cases the energy is disappeared over the resistance of the resistor or over the internal resistance of the capacitor (and the resistance of the wires/copper-tracks). Simple example: If you have two capacitors with the same capacitance, one loaded with 3V, one with 6V and you connect both of them, then the charges are flowing into the 3V capacitor and each of them will reach 4.5 Volt. One 1F capacitor with 3V has 4.5 Joule. One 1F capacitor with 6V has 18 Joule. (So we have 22.5 Joule stored.) Two 1F capacitors with 4.5V have 20.25 Joule. (now the charge is equal) => 2.25 Joule are missing. This is the same amount of energy what you would need to load two 1F capacitors to 1.5V. So the whole difference is wasted. There are 3 types of balancer and only this balancer with coils can pump the energy efficient into an other cell. The problem with this simple coil-balancers is the high voltage difference what they need to be able to work. For me they are useless. Would be nice, but they do not make a good job, because they left still a big voltage difference. At the end it is the best to use the capacitive balancer only as a top-balancer during the loading process. I would deactivate the resistor balancer of the BMS or use it at the same time if the capacitive balancer is activated.

[@mikebash7790]

Thanks for your great work Greetings from Bavaria!

[@camelbakbfm]

thank You for Your work, I see that makes You happy!!! You happy guy. Do You think that having 2 longer busbar ( 3AWG 2 meters long) in the batterypack (max load 80A) and active balancing just at 3.45v is good idea???

[@michaeldudley7840]

Andy, can you test some of the other smart active balancers that are available now? (JK, Qucc, etc.) Also, do you know what the "docking adaptor" they're offering for them is?

[@Jonyys]

great test with very useful results. thank you very much

[@tzapulify]

amazing tests, amazing content. do you happen to know if the bms in that can also run with 15 cells/15s ?

[@kristjanaiaste]

Well made point. I wonder if you now discharge it again and charge back with AB on at 3.45, would it be even better :)?

[@kuhrd]

I have an active balancer on each of my big packs that are always connected but I have an inexpensive voltage controlled relay module that looks at the total pack voltage and turns on active balancing via the solder pads for an external switch once the pack is over 55v. This is effectively the same system that many of the BMSs that have a small passive balancer and a port for an external balancer are doing. At the time and probably even now, this is still a less expensive option than a programmable NEEY active balancer if you are on a tight budget but the NEEY is nicer to work with and has less steps to make that happen if a person is not as inclined to figure out how to add and setup a programmable voltage controlled relay.

[@paulcurtis5496]

Like# 1! Loads of Monsoon rain happening here in "Always Hot & Sunny Tucson"

[@boringsoftware2093]

Hello OffGrid Garage Man, have a similar situation. Cell 5 is ALWAYS the lowest? Is the cell defect? Or is this "normal"? (so all cells are constantly balancing into that Cell 5 = bad it will take down the voltage of the whole block for nothing) U ARE THE EXPERT so no balancing below 3.45V?

[@wayne8113]

Thanks Andy 👍

[@uwerammelsberger7855]

Einfach mal wieder ein klasse Video. Grüße aus dem Schwabenland.

[@karisianschwermer6464]

The first relay contact switches to continuity in the event of an alarm. Couldn't you disable all alarms in the parameter settings except for the pack overvoltage alarm? Then you could turn the active balancer on and off via the relay with the pack overvoltage alarm setting. Personally, I don't need these alarms anyway. Then either turn off the red flashing LED as well or take it as a sign that the active balancer is working.

[@karisianschwermer6464]

Does anyone know under which condition the second contact switches? I can't find any documentation on the BMS at all.

[@Drillmechanic]

To work correctly during charging and discharging, the active balancer must know exactly what the full capacity of each cell and what SoC of each cell is at the moment!

[@ahbushnell1]

Put the battery at 50% charge and let it sit with the balancer on for a few days then charge up and see if the balance is good.

[@davidpenfold]

I guess the cruellest test for the inbuilt active balancer versus the Neey would be to keep the active balancer on during full discharge and then switch it off just for the full charge. Then you'd see the full effects on the cell deviations of constantly balancing compared to top balancing only.

[@jasonbroom7147]

At the end of that process, just like at the end of this video, it just wouldn't be enough to matter. For all practical intents and purposes, this is hair-splitting of the highest order. Millions of people get excellent service life from batteries, day in and day out, with greater cell deviation than was displayed in this video. In fact, Andy has been asked quite a few times how much cell deviation you can have before it's a problem, and what the net impact is on total capacity or pack longevity. I don't know if he's researched it, but I have, and cell deviation of 100mv is considered normal and completely inconsequential. What he's doing, with these endless tests on cell balancing and deviation, is like loading a semi truck trailer and obsessing over 1 or 2 pounds of weight, in terms of proper distribution. Complete waste of his time and ours, especially since you can't even see the "problem" he's claiming exists...until you charge WAY higher than he ever recommends! Think about it.

[@davidpenfold]

@@jasonbroom7147 cell deviation at the top after a full charge with no active balancing may be wildly higher after a nosy active balancer has been balancing during the whole discharge process. That was my point. It's all in the interests of science!

[@ForwardGuidance]

"Complete waste of his time and ours" Why are you here if it is such? Learning the nuances is interesting. Obsessing over an issue for best course of action is called research and if one can't determine a best course of action then more research is required. I don't think loading a truck is a good analogy. @@jasonbroom7147

[@rcinfla9017]

In the normal situation, when you have inverter pulling variable loads during the cycle it will cause the always on active balancer to screw up the cell balance even worse. The variance in cell slump voltage with inverter load will cause always running active balancer to make incorrect balancing direction decisions.

[@marijnvroegindeweij5001]

Andy! What’s the black mark on your right arm? Ist was not there before but even After days and days and showrering it stays there…

[@K3iVi]

And how about a passive balancer for example on 280ah cells 16s balancing power max 200mA. Does it unbalance battery when kept active all the time for example from 3,2V? Is it better to keep balancing start high at 3,4-3,45V?

[@egnegn123]

For me it is still no proof because in the last cycle the battery was balanced down to 25 mV, which is much much better than 35 mV in the cycle before. If you do another cycle with balancer on you will now get a better result again.

[@quilmore]

other than pointlessly looking at delta voltage between cells, what total battery capacity difference would that make? I'm guessing it's just 1% of capacity, many other variables can make or lose that much on a battery that it's not worth losing sleep if the active balancer is on or not, which will catch up after a couple of cycles when charge is available, do a capacity test and compare values rather than looking at cell voltages, that's what matters

[@aaaaaaaaaa5446]

Hi Andy. Which BMS would you recommend?

[@HellTriX]

Within the last year you were saying the JK BMS is the best BMS to use. Have you changed your mind to saying the NEEY is the better BMS now? I built my first 48v@280AH pack with the JK BMS, but I am about to build 2 more of those and need to know if I should get another JK BMS or a NEEEEEY?

[@ForwardGuidance]

I think the NEEEEEY is just an active balancer, it is not a BMS.

[@coolandrew951]

What is the difference between the basic vs standard cells in the gopel battery.

[@markjedlicki977]

The 4a Bluetooth balancer is not NEED it is an Active Helte balancer from Gobel, would you still recommended the upgrade?

[@OffGridGarageAustralia]

Gobelpower has both, the 5A Heltec balancer is the 'always on balancer' and for US$60 more you can upgrade to a NEEY and program it the way you want.

[@markjedlicki977]

The Bluetooth upgrade is the "Heltec 4A Bluetooth Balancer" if you to the software link you will see the software and when I contacted them to get clarification it was that heltec 4A bluetooth balancer for price quote on the upgrade.@@OffGridGarageAustralia

[@SrStew]

So what active balancer or bms do I want to balance a bunch of 3.5 to 3.6 cells to 3.0 and 3.1 cells (16s2p) or do I have to tear everything apart again to individually charge each cell to 3.4 then connect to be top balanced?

[@be4744]

Andy, the basic model (with 4A neey balancer) brings according to gobel power website a voltage range of 49V - 54.5V. Is this correct ? What is your opinion about the basic model? Because I think you tested the premium model with eve cells... maybe gobel sent you a better version than the real basic model reflects...

[@OffGridGarageAustralia]

I would not buy anything else than the basic version with the 4A NEEY balancer. Once top balanced, it will charge to whatever voltage you want, up to 58.4V, no problem. It is a bit confusing why they say it's not charging higher than 54.5V. They test all batteries unbalanced to make the batteries comparable. The basic model has just cells which are not as tight selected as cells for the other models. But the balancer will fix that, 100%.

[@be4744]

@OffGridGarageAustralia Shit, I read your answer to late and payed now already an upgrade fee of 430$ to get a standard version. However, with this I think (hope) I get 5 years Limited Warranty also to the BMS, 1.2kWh more capacity and 10kW output power instead of 7.7kW. Was this worth the money?

[@tresleguas]

Help please... Is it possible to build a battery with the cells arranged in a different way than we usually see? I am planning to build a battery in which the cells are lying on their side...is this a bad idea...?

[@bishwagit]

Please link the stuart active balancer video

[@laurentsantaibambu7324]

Hi Andy! and thanks again, obviously the Balancer being active 24/7 is of no use, And certainly it takes energy and can reduce the capacity of the battery.. Definitely a balancer like Neeey or your system with the relay voltage detection, is the right solution. But I am very surprised! the difference in the main voltage, in the 2 tests?? Very strange?? that there is a small difference, we can hardly understand, but there? a difference of around 2 volts at the main voltage, is that strange? If indeed it is because the Balancer is active all the time!? this is really not good! I have never encountered this problem, but obviously my battery packs, never a Balancer active 24/7, always controlled by the starting voltage and the delta of the cells. Thanks again Andy, and we'll see the next test...

[@SolAce-nw2hf]

I have an unusual idea. How about a load balancer with a dedicated connector for a spare cell that can be used to top off the highest voltage cell so that other cells are not interfered with? It should also be able to charge to full if the other batteries are (almost) done charging. That way it could assist worn cells while not needing to be perfect itself. Just wishful thinking maybe with 16 cells, it could just save a battery from the scrap heap.

[@bascomnextion5639]

There is an IC that uses a cell/battery that works very much like that its for lead acid batteries

[@stanislavmlcuch2085]

Is it possible for Gobel to add switchable active balancer? In this state you could put there manual switch as you did it on QSO battery. And did you know that Gobel offers battery with JK BMS?

[@Sbellins1109]

Hi, i have a 300AH 24v battery (304ah cells), what active balancer do you seggest me to use? I was looking at the Heltec 10A or a QUCC 10A. Initially i was interest in the capacitor once but helted suggest not to use it or to put 2 of them in parallel because i have big cells. In your opinion what balancer should i use? The ney is too expensive becasue i have to buy 2 for 2 separate batteries.

[@jasontaverner2634]

balancing at all voltages also micro-cycles the cells, if thats something that concerns you......

[@abhishekkushwaha2455]

Hey andy !!! can you please suggest me a good bms out of many that you have tested.

[@you2bevsgoogle]

Ist das Problem nicht das der Active Balancer immer an ist ? der hat kein Ein Aus Schalter. Der sollte eigendlich nur arbeiten wenn genug Sonne da ist und die Batterie geladen ist,sodass der Überschuß direkt von den Modulen kommt und solange da strom da ist,kann er die Batterie balancieren.Problem 2 sollten mal schlechte Tage da sein wo die Batterie nicht richtig aufgeladen werden kann,balanciert er wieder,man sollte den ausschhalten können.

[@DanBurgaud]

21:15 At this point the cells are totally whacked with >200mv delta and will stay like that for an extended period of time. The Active Balancer (AB) will "Bottom Balance" it until the sun comes up; and when it does, the cells are totally unbalanced when they reach >3.5V. I dont like AB connected all the time. It should only run at >3.5V (for top balanced battery), (or

[@jasonbroom7147]

Do you realize if you didn't have an AB connected, and were just using a battery under normal conditions, that >200mv deviation is not only normal, it is entirely expected, will only exist for a relatively short time, and would have virtually no impact whatsoever on total pack capacity or longevity? Do you further realize that a proper BMS is constantly turning on and off discharge mosfets while the battery is under load, essentially causing the same "problem" Andy is claiming exists with an active balancer. All an AB does, irrespective of when it runs, is attempt to keep cell voltages as close to the same as possible...which is exactly what a BMS does, minus the ability to draw current to add to a given cell. Much to-do about nothing!

[@uhjyuff2095]

Wish you would have turned off the BMS internal balancer for the non balancer test charge

[@schunkelndedschunke6914]

Great test. Thanks

[@SkypowerwithKarl]

You’ve proven this multiple times and I’ve seen it myself. It’s fact! Since you’ve been seeing lots of clouds lately, how about showing us what your cloud edge effect looks like on output. Sometimes I do a double take when I see the power here.

[@acinfla9615]

Andy2 said you were only at 57.2 volts! But then again I think he has been drinking so I can’t always believe what he says ! He is usually half drunk anyway!😂😂😂

[@PlexMulti]

Ευχαριστούμε!

[@OffGridGarageAustralia]

Thanks for your ongoing support!

[@DanBurgaud]

26:35 or they are using their batteries within 20%~95% only where balancing is not even needed (thus "no issues").

[@garys-half-baked-offgrid-dream]

Hi Andy, I bet the long suffering Mrs Andy really appreciates your cold feet when you sneak into bed!!!! 😂😂😂. Thanks for the shout out your a legend! It was this upcoming series that spurred me on to screen record just what really bad looks like. I need to test cell 14 vs another "good 🤔" cell to see what's what. I am confused why I have a massive Delta V at the bottom of approximately 0.6v but up the top I can get to 3.5v before the cells really start to run away. Why do I not see the same deviation at the top? These cells are not fair on the Daly, I still love it but yes I concede, an active balancer has been ordered 😂 All in all very good practice. Thanks very for your hard work and knowledge sharing. There is no better University and community. Shine On! Gaz 🏴󠁧󠁢󠁳󠁣󠁴󠁿

[@PLTSsederhana_]

Amazing ❤

[@leondavibe]

maybe they are from South Africa or use their batteries the same way, thanks to load shedding we recharge the batteries to full daily using utility if needed to be ready for the next session of no utility power , spending enough time at full daily or even a few times a day to balance again some days we have 3 sessions without power i found that under lower current with badly matched cells the delta between cells i found to be bigger, and not as bad under heavy charging current maybe it is just me and its been a while so hopefully my bad memory isn't feeding me bad info

[@airgead5391]

So listen carefully, I will say this only wence: Again confirmed that we can't do without a NEEEEEEEEEEEEEEEEEEY.

[@GapRecordingsNamibia]

Proof is in the pudding as the saying goes.

[@deh_developer2725]

Remain Capacity is atmos the same

[@keyem4504]

I really wonder where the black patches on your arms, that we can see in the last videos, come from. 😉

[@Dutch_off_grid_homesteading]

Heya, 19V in moon light that is nice just 10 years the technic will be so developt we can me power from moon light lol

[@markspieth7591]

You would think that since GobelPower do their own BMS, they could have an output to control the active balancer. Would not be hard.

[@LarryKapp1]

It is a Pace BMS in this battery.

[@rwd6spd]

If this balancer has the ability to have a switch attached to the PCB then, why couldn't the DCTs (dry contacts) be used to trigger the balancer?

[@LarryKapp1]

@@rwd6spd Look at the first review Andy did of the Jakiper battery. He briefly tested some of the contact pins and if I remember correctly they only worked for certain alarms and not other things. But maybe this is a newer version Pace BMS and would work for that . Maybe Andy will test those out sometime.

[@igorkvachun3572]

Yes video👍⚡ 🔋💡

[@houseofancients]

Well, hate to tell you I told you so..butta. ;)😊

[@AlsinoFerreira]

😎

[@janosvarga962]

Sadly no EU stock and VAT and taxes makes it unviable.

[@Foxfried]

You did the test EVERY time with grade B cells... If you really want to do it do with Grade A cells, they don't have self discharge problems of grade B.

[@ericblackburn9829]

I've been waiting for this one. I have built 2-300ah 12v LifePo4 batteries, and had to add active balancers. Unfortunately they run all the time. It works as I only have 510 watts of solar, so my balancers can keep up with them.

[@camielkotte]

I haven't got a clue what you just explained. I dounderstand this video very clearly.

[@cdonuts7335]

😂😂😂 I suppose you have to start somewhere a couple of 300ah 12v batteries and your telling me I don't know what I'm doing! 🤡 Balance away😂😂 honestly 🙄

[@ericblackburn9829]

@@cdonuts7335 Will do. Thanks

[@teddypreston5525]

Another channel gone to reviewing stuff that dealers send to them. 🤔 A real shame. How about a good LTO in depth study. I said “study”! I can’t afford half the stuff he has shown in the last 5 or so videos.

[@cyberplebs6577]

🐸🐸🐸

[@opless]

Second!

[@jasonbroom7147]

If the balancer is active all the time, and let's say for the sake of argument that it does create some imbalance while the batteries are in the flat portion of their voltage curve, won't that be corrected whenever the battery cells get to a high enough voltage? I mean, in your video, you show extremely low deviation while the active balancer is working, with cell voltages in the flat portion of the curve. The only time there is significant enough deviation to even give consideration to is during charging, before it hits a high enough voltage. This is true for any battery; deviation is highest during either charging or a fairly high C-rate discharge. I hate to say it, but you worry way too much about cell deviation, obsessing about the tiniest minutiae, when your very own testing shows this to be a complete non-issue. It's odd how you're arriving at the wrong conclusion...when the final result (in either case) is deviation that is far too low to even bother with.

[@ericblackburn9829]

I see where you're going with this, but the difference in voltage in flat part of the curve can be caused by different reasons, not just exact state of charge. When you think in amp hours rather than voltage you get a better picture. Say two cells are at 150 ah left in them, but there is a .1 voltage difference in the reading. The balancer will then try to take amp hours away from one cell and put it in the other. That is what causes the imbalance. Imbalance is a function of state of charge. The voltage indication (especially at the top and bottom of the charge cycle) is a result of state of charge. So lets say one cell is at 145 ah and the other is at 155 ah after the balancer tries to balance during discharge. That's a 10 amp hour difference. When you get to the top of the charge cycle, that would take a 5 amp balancer 2 hours to correct at minimum. And as we know, unless you charge the batteries very slowly, the voltage rises very quickly at the end of the charge cycle. I hope this helps, but it is awfully wordy. This is complicated stuff!

[@ericblackburn9829]

And I'm going to say this as non-confrontational as possible. Try to watch this again without confirmation bias. His objective was to prove that leaving the balancer on all of the time causes an imbalance in the cells. The imbalance can only be recognized in the top or bottom of the charge cycle. The fact that the cells were more unbalanced with the active balancer running all the time, proved his point. And as for worrying about an imbalance, it is an issue. If you allow the imbalance of LifePo4 cells to continue to get worse over time, you can have a cell over voltage disaster (Covd ha/ha) eventually. Like a really bad one, cell expansion, leaking, shorting, etc. Not to mention if it happens under high load, the mosfets on your BMS could fail. And mosfets should not be constantly activated, they're not designed for that. If you're not concerned with cell imbalance, you may want to watch some videos on the hazards of overcharging LifePo4. Yes it takes a lot of voltage to cause a disaster, but over time, unchecked, cell deviation will only increase.

[@cdonuts7335]

Andy has always been balanced obsessed from day one! The deviations are so minute! Just let the balancer do its thing, it's not going to be able to control every electron! If he's that concerned he should slow the charge rate but I don't think he pumps big amps into anything from the solar off he's roof anyway!

[@ericblackburn9829]

@@cdonuts7335 say you don’t understand batteries and solar without saying you don’t understand batteries and solar…

[@cdonuts7335]

@@ericblackburn9829 I don't pretend to know anything, I don't chase fractions of a volt or a couple of amp hours here and there. Mine power our house and that's all I worry about! I have better things to do! I leave that to you guys 😂 have fun!

[@odedeyidamilare]

19V in moonlight 😂

[@mindbender50]

Don't say active balancer connected say "running" :) Just razzing you :)

[@PlexMulti]

Im late

[@KevIsOffGrid]

0.7amps, 53v, that's 37w, .... surely it should have been 21w :)

[@deunansolarcavern]

First!

[@Pimpasxx]

Hi Andy. If you keeping cells up to 3.5v only ,the inbalancing on the top of 150V is no problem ? Migt be better to do bottom balancing ?I got Lion S14 .I balanced at bottom (winter time) and left with no balancing for 2 months ;)