Just purchased two 8S balancers to see if that fixes it. User "fox fried" made a good point. If one bms disconnected, you would have a disconnect halfway in the pack. Which could cause the voltage to rise. Makes total sense considering what part of the board fried. Part two coming soon ~~~~~~~~~~~~~~~~~~~~~~~~~ Does off-grid solar confuse you? Check out my DIY friendly website for solar system packages and product recommendations, and so much more! www.mobile-solarpower.com Join our DIY solar community! #1 largest solar forum on the internet for beginners and professionals alike: www.diysolarforum.com Check out my best-selling, beginner-friendly 12V off-grid solar book (affiliate link): amzn.to/2Aj4dX4 If DIY is not for you, but you love solar and need an offgrid system, check out Tesla Solar. Low prices and great warranty, and they can take your entire house offgrid with their new Powerwalls: ts.la/william57509 ~~~~~~~~~~~~~~~~~~~~~~~~~ My solar equipment recommendations (Constantly updated! Check here first): 12V/48V Lithium Batteries: www.mobile-solarpower.com/solar-batteries.html Solar System Component Directory: www.mobile-solarpower.com/solarcomponents.html Plug-N-Play Systems: www.mobile-solarpower.com/full-size-systems.html Complete 48V System Kits: www.mobile-solarpower.com/complete-48v-solar-kits.html DIY Friendly Air Conditioner/ Heat Pumps: www.mobile-solarpower.com/solar-friendly-air-conditioners.html Complete 48V System Blueprint: www.mobile-solarpower.com/48v-complete-system-blueprint.html ~~~~~~~~~~~~~~~~~~~~~~~~~~ My Favorite Online Stores for DIY Solar and Coupon Codes: -Current Connected: SOK, Victron and High Quality Components. Best prices and warranty around: currentconnected.com/?ref=wp -Signature Solar: Cheap Server Rack Batteries and Large Solar Panels: www.signaturesolar.com/?ref=h-cvbzfahsek -Ecoflow Delta Official Site: My favorite plug-n-play solar generator: us.ecoflow.com/?aff=7 -AmpereTime: Cheapest 12V batteries around: amperetime.com/products/ampere-time-12v-100ah-lithium-lifepo4-battery?ref=h-cvbzfahsek -Rich Solar: Mega site and cheaper prices than renogy! Check them out: richsolar.com/?ref=h-cvbzfahsek -Shop Solar Kits: Huge site with every solar kit you can imagine! Check it out: shopsolarkits.com/?ref=will-p -Battery Hookup: Cheap cell deals bit.ly/2mIxSqt 10% off code: diysolar -Watts 24/7: Best deals on all-in-one solar power systems, with customer support and distribution here in the USA: watts247.com/?wpam_id=3 ~~~~~~~~~~~~~~~~~~~~~~~~~~~ Contact Information: I am NOT available for personal solar system consult! If you wish to contact me, this is my direct email: williamprowsediysolar@gmail.com Join the forum at diysolarforum.com/ if you wish to hang out with myself and others and talk about solar FTC Disclosure Statement and Disclaimers: Every video includes some form of paid promotion or sponsorship. Some links on this youtube channel may be affiliate links. We may get paid if you buy something or take an action after clicking one of these. My videos are for educational purposes only. Information is subject to change/update at any time. Electricity is DANGEROUS and can kill. Be smart and use common sense :) DIY Solar Power with Will Prowse is a participant in the Amazon Services LLC Associates Program, An affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com

I'm using a very similar active balancer (with screw terminals) on my pack with used 180Ah cells for several month now. The balancer actually made the pack usefull since my BMS never managed to balance the Pack. It's perfectly balanced now.

Excellent test and information Will. It also confirms what I've observed with active cell balancing compensating for variations in individual cell chemistry during cycling and ended up severely unbalancing the pack. When removed the active balancing, and let the BMS manage the charge in two deep charge cycles the pack balanced nearly perfectly.

I use the Heltec brand of these (looks the same but yours is missing the heltec silk screen) but mine work like a charm man!

I have 2 of these active balancers on 2 separate 48v systems running for months without issue. Your pinned comment is very likely correct that having the pack split between 2X 8S BMSs caused the issue. Also, these balancers have a solder blob across the pads for a switch. I have this set up in each of my systems with a voltage control board so that it doesn't enable the active balancer until the total battery voltage goes over 54v. This helps keep the whole system top balanced at a much faster rate than you would get with a regular BMS so you don't get the short cycling on and off if it has been a few weeks since the batteries have been fully charged up and it doesn't try and balance at the bottom end of the discharge curve. If I had new batteries I likely wouldn't need the active balancer but it is still a whole lot faster at fixing any cell drift if I have a nice sunny day after 2 or more weeks of cloudy/overcast days where the batteries didn't have a chance to get a full charge.

i have been using an active 8s balancer for more than a year now without disconnecting it once and dit works really good

Same exact thing happened to me with the same 16s lifepo4 pack and the capacitor type balancer. The wires to the balancer got really hot and the balance board too. Immediately disconnected for fear of fire hazard. 5 years later I built a 4s car battery and used the same type balancer via 5A fuses and it works beautifully. Balances down to 12mV. Maybe we both got a bogus 16s version. Keep of the great work Sir.

I have active balancer and working fine since two years almost

I think you should check the connections with voltage meter first before connecting it. I have a few of those in my own battery pack and they work greatly 🤷‍♂️

Damn Will, I JUST had received mine and did a search to see if I was missing anything before wiring it up short of the 16s capability. Of course I chose your video first lol. 36v 105ah pack here using the same balancer. I loved that I could use it with my current 12s and then keep it for when I upgrade my golf cart to 48v/16s. After watching you, I was reluctant to charge overnight with it so I actually rolled my cart outside and away from any fire hazards before starting the charge cycle... lol In the end, mine worked great and isn't even warm to the touch. I had one eye open all night tho!

I have the 4s version of that balancer. It worked fine for me. I had done a top balance of the 4s pack but a cell that started drifting and would peak before the others shutting down the bms. At first I kept the balancer 24/7 and it balanced great but after a couple of days I saw that it kept balancing on low SOC and managed to make another cell drift only on peaks. So I disconected it when it balanced at a high SOC ans cell voltage of 3.55 a week ago and lowered the boost voltage to 3.475. So far the pack is balanced with no more than 20mv difference at boost. I will use it for periodic maintenance of the pack without having to dissasemble it and top balance.

My 2 year experience, with the same. The BMW electric car battery back had a damaged cell that was only 20 amp hours when the pack was supposed to be 200Ah for the 16S pack. Two of these in parallel allow me to cycle the battery with 150Ah of capacity running a refrigerator. The current will exceed 5A with huge cell voltage difference, if cell gets to 2v for example. The system can only do high power in small bursts that use up to 15ah of power, before I trigger the cell difference cutoff, but it returns to stable quickly with 2 of the 5A balancers. Exclusively solar systems never have a chance to top off so active balance is sometimes necessary.

I use the QNBMM balancers work down to a couple millivolts. Usually settle within a millivolt.

A quick scan with your IR camera while the balancer and charger are running might give you some piece of mind. If your right about a voltage spike after one bms disconnected you probably wouldn't wouldn't have caught any thermal anomalies at the time, but at least you've checked your work before walking away from a battery that big.

Active balancer does the job, unlike onboard bms balance so slow pretty much no balance at all. It just cant take the heat. Better to isolate the balancer next to the batteries with better air cooling. Looking forward for the next one.

Will: Johnny on the Spot! I was up until 2:AM this morning wondering and researching about active balancers. I am still wondering, but this video goes a long way toward convincing me that active balancers are not worth their salt. 😫

From what I have gathered an active balancer on LiFePO4 batteries is only good for doing the top or bottom balancing on an already assembled battery. If you plug it in while the battery isn't very close to full or very close to empty it will just continuously try to balance based on voltages and possibly unbalance the battery even more. But they are good tools to have when the BMS is cutting out at the top or bottom because it's balancing current capacity is too small. That is the time to use the balancer to get a quicker top or bottom balance since the voltage differences are actually indicative of charging state differences.

Over my head, but important for me to understand the complexity and danger.

I’ve got small active balancers on two diy Nissan Leaf gen1 4S style batteries (one is 4S3P the other is 4S6P). These only seem to kick in when the cells are heavily discharged, but seem to work then.

Solar engineering did a video on that balancer. The cell voltage difference needs to be extremely excessive for it to balance at anywhere close to 5 amps

The NEEY active balancer works great though and has settings to only balance above a certain voltage

I was thinking of putting heat shrink on the handles of my tools. Like the socket wrench. It should greatly reduce the chances of dead shorting a battery.

The "Up in Smoke" section: now sponsored by active balancers

You should test a Batrium fancy BMS 😁 You can see what it's doing on the computer screen, and it logs everything

Finally someone that is not looking at voltages!

I have two active balancer in each pack working flawlessly, however, at the beginning I notices in the app that cells voltages were fluctuating and acting erratically. l have to check each wire with the ohmmeter and found that some ring terminals were crimpled incorrectly over the wire insulation making faulty connections. After the faulty terminal were replaced with proper connection everything started working without any more problems.

Same smoke here, that's why i search this info. Run a S8 200Ah lifepo4. Was pretty well top balanced after 1 cell was abit down. And Just wanted an extra balance function because bms do not. Looking out for something else now

I've been playing with the 4s version on my new 400ah 12v 4s pack. No problems thus far (I only let it run while I'm in the shop) - But it does seem to always be balancing... In an off grid situation I could see where it would drain the battery if you're not careful.

So i wanna share my own experience with this things: Side Notes: 15S - Li/Ion - minV 3V - maxV 4V - Ah 460 used Tela Moduls First of all, i wouldnt sept at all, if not all cabels are fused with this size of pack. At first i only used a chinese progammable BMS, but at this time i also use the internal fuse ( thin wires) so the cables are propper fused. I also added 5x20 3A fuses for all balance cables that go to the BMS. Then i went with the Batrium BMS and it worked fine. But afer month i checked the voltages and they were at 50mV difference. I bought one of these balancers like you. Then my mind change to i played with the settings when the bms start the balancing process. My pack is full at 4V and you should never think --> the sooner the bms start with the balancing, the better is it. Now: I didnt use the active balancer at all, the voltages are within 20mV now and they sink I set it now to 3.85V to allow the ballancing So i would never use one of these balancers, because they are not programable. In my case the balancer would start the process way to early.

At least you mentionned the Type of Batterie. Else you have a burned balancer board and nobody knows Why.

Top Balance.... Done..

i use a heltec 6s balancer on a yinlong lto bank 80 ah . after top balance i hooked it up works great. after 1 week still good....

Damn... I installed one of these on a 96ah headway bank, 4s12p @ 14.6v. it been good for the last week, but now I'm thinking to go back to the passive balancer. It has not let the smoke out yet, but now I'm stressing on it! I use the setup for car audio, so it see's an incredible amount of voltage fluxuation constantly when being pushed. I'm weirded out now! Going to check it this very moment.. Update - Cells are perfectly balanced, board is cool to the touch. After reading other comments, I'm pulling the bastard. Insurance won't cover a fire from one inside the car I'm sure. I thought I was "upgrading"... 🤣

Think about heatsink on transistors.

Had the same problem here two times. Same Inexplicable heating and the capacitors hot. Ladder track burned out. I switched to another type of balancer.

The Bluetooth active balancers that come in a metal case seem to be fairly reliable. I've been using a 2A version for a couple of years, so far so good. The product I'm referring to is to one by JK BMS that is sold under various brand names on the usual sites with Chinese electronics. It has some nice features like an On/Off slider in the Bluetooth app, adjustable balance current, (0.2 to 2.0A) cell delta voltage trigger setting, internal cell resistance display. The one thing it lacks is the ability to set a low and/or high voltage threshold value so balancing ONLY occurs during the lower voltage part of discharging and the upper voltage part of a charge cycle. Cell balancing in the FLAT region of the voltage curve is not necessary and may even unbalance cells more. As mentioned in the video, If you have a set of cells that are not well matched like I do then the active balancer does help quite a bit. BTW, Off Grid Garage just did a couple of videos on the same balancer featured here. His did not "burn up". Perhaps you just got a bad one?

Active balancer becomes hot when balancing. I've glued my balancer to my bms as its heat sink. I've been using it for almost a year now. I'm using the 1.2A version.

That balancer failed for me but I ordered two. The second worked but if you do high charge currents the board may not keep up and cells can over voltage. My testing was on lto 20s.

Did you connect the active balancer in parallel with another BMS? Couldn't that be the issue?

I have one of those on a 48v 150ah system. when cell voltage goes above 3.38v, the positive and the negative cells connected to charger and can reach 3.8v while the others still at 3.4v or so. and yes, I have top balanced them to 3.65v in parallel. good luck!

Sorry to hear that man. Did you set the solder jumper correctly for your battery chemistry?

2 things, I would like to know if that balancer is 2 smaller balancers running half and half, or 2 smaller balancers with one cell being overlapped, or if its actually one single balancer... The latter options all work fine with this design, they're basically a series of capacitors (or banks of 3 by the looks of it) that have a MOSFET matrix that connects each capacitor in parallel with one of the battery cells, and then a second bank of MOSFETs that connect all the capacitors together in parallel. They're basically doing the same thing as if you manually rewired the pack so all cells were in parallel... only because they're capacitors that are rapidly switching between parallel and series, they are able to effectively place all the cells in parallel WHILE they're operating in series without any major issues... however this means that balance current is directly proportional to voltage difference between cells, and it also means that if a MOSFET or capacitor fails... bad things can happen. Looks like one of your MOSFETs either failed from something like thermal runaway or they somehow didn't disconnect properly when needed. There is a little oscillator that changes which set of MOSFETs are connected, if say one MOSFET didn't disconnect... well that would cause the board to burn.

I burned an identical one, but identify the problem, the busbar nuts were loose and therefore there was bad contact between the cells. check the tightening torque of your nuts

So do you need to charge the batteries at the same time when doing a top balancing?

Before plug in should be check wiring by multi-meter

ok am using active balance however i do not use bms but my max volt is 54.6 however i realize if you increase te voltage the active balancer capacitors will hot & burn the first one burn & i replace it & it working good so check the voltage maybe too high

be warned, those capacitor active balancers can explode if the cell delta gets too much as they then chuck out very high amps. Mine exploded near 98% depth discharge on 18650 pack ...yep was bound to be a big difference of cell voltage. Nearly caused a fire. Best way to use them is when Lifepo4 battery is fully charged, then just use them to top balance around 3.55v to 3.65v for a relative short amount of time it takes to balance them up. Then disconnect...do not leave them on the pack as they will balance all the way to full discharge leaving you with a very uneven pack. They do work great but only above a certain voltage and for top balancing.

Bummer. Please, share your views on top vs bottom balancing. Which is better? Thanks for sharing.

Will, can I use an AC to 18650 battery pack? I have 14S 26P 48V system.. thank you.

I have the exact same one but it's 17s. So the last red lead should not be used. Could that have been the problem?

I have this same active balancer. Been running just fine for months. I used it in place of a top balance and worked like a charm. It is too bad it didn't work out for Will. But did he really want it to work?

What about super capacitor Battery please test one

I have 2 SOK 48v in parallel and 2 24v renogy in series do i need a battery balancer for my solar RV SETUP

Are you getting another to actually test?

If I buy 10-14s, can under 10S also use this battery balancer?

Couldn't a balancer just moniter/switch out charged cells?

Please also check that all bms should have a Voc threshold published......mppt CCs can let the voltage splike for couple of seconds which is common even for the most expensive CC's... acid vrla sla or gel batteries won't see these spikes...but the bms will cut out the CC from the battery after only 1 second of these overvoltage spikes letting the CC to ride freely at the pv Voc....and that's a concern when the bms encounters this voc at reconnect point,...it can be fried...

How will conect 3.7v 5000mah 48pic to get 12v 100ah

Just assembled a 280Ah lifepo4 pack with Overkill 16s Bms and the very same balancer yesterday. It lasted about 10 seconds, then one of the capacitors literally flew 2 meters away and the whole thing went smoking.

I use one of these balancers the one thing I thought about is it wont turn off in a low temp disconnect situation, for example battery is below zero and you discharge it one of your cells is out of balance it flows energy to the low battery so effectively charging at 0c albeit at low rate.

I didn't know you could use a bms and an active balancer together.

You can cast the balancer in synthetic resin. This dissipates the heat better and makes the balancer largely fire-proof. I've already done this on 4 of these balancers. ;-)

I have a all in one growat inverter and when a typical bms shuts of the battery when it discharges to much then......yes....the inverter shuts down.....if the inverter communicated with the bms to know that it should stop taking power from the battery then it would be the best but there is no standardization on the commutations ports and im to lazy to make it work so a active balancer is my only choice, and the inverter handles all the switching (you can set up all the voltages in the inverter including discharge and charge AMPs)

I tried 2 different 4s balancer.Seemed to work at first but not for long. Mines didn’t burn up it just stopped working. Or never worked. Idk

Could it have been that your cells were so far out of balance that the balancer went over it’s 5 amp limit?

The off grid garage guy doesn’t like active balances either, but he says they great for getting a new pack up to speed. He also says once the battery pack is up to speed you should take it off the battery pack until the battery pack is way out of tolerance again. He has hours of data to support his findings.

have 8x 12v 100ah liion batts for a bank. (48v) can you recommend me a devent inexpensive bms to manage all? thank you

May be it must put in a ventilated place

i have an active balancer similar like that one on my 8s battery with 280 AH cells. I have new cells, i got the balancer just in case. That's unfortunate for yours.

Could you please review the Ohmmu lithium after market battery for tesla model 3/y? It seems so expensive for such small battery. Is it possible to get the same thing from someone else?

Discharge balancer / active balancer interactions

Off-Grid Garage has dome some interesting videos on active balancers too.

Hmm.. Odd. The Off Grid Garage guy in Australia seems to have some pretty good luck with his active balancers. Maybe try the brand that he's using... Just an idea.

active balancers seems cool asf ! :-p

Cruising sailboats with electric auxiliary engines routinely go weeks or months operating in a pSOC. Depending upon weather they can find it impossible to reach full charge off of solar. Drifting cell balance can be a real problem that has to be dealt with. How should we deal with it?

Either the balancer was defective (using dodgey parts) or it ran at such an imbalance for so long that it overheated.Theses are simple versions of active balancing, quite dumb actually, they just connect caps to the cells and then disconnect from the cells and connect the caps in parallel (now all caps are balanced) then back to the caps across the cells which dumps power into low cells and pulls power from high cells. They don't have overcurrent protection for themselves and therefore could likely overheat if left a long time on a large pack that is very unbalanced... either that or one of the components was already about to fail from the factory and just quit. So I'd look at mounting where it can get some passive airflow and where the balance lead is not likely to rub on the busbars for peace of mind. Some inductive transfer units probably self limit their current but they balance from cell to cell like a bunch of 2s strings connected together which means that on larger (more series) packs, it is possible to have one cell high, then the next just a bit less high, all the way down to the low cell, the capacitor balancers will asymptotically approach perfect 0V difference balance because all cells equalize at once to the average cell voltage.

Maybe it overheated because you had the board sitting on the plastic container.. should have had the board on stand offs so there was airflow underneath

Awesome video! Love seeing a video where things don’t go by script. Tough to tell if it’s “chinesium problem” or maybe it needs a heatsink? Don’t you have a thermal camera (i just picked up a Flir v3 for the iPhone ) Please consider a follow up video, after seeing if the manufacturer will replace the unit.

hey i really need your help. i want to have a power source to run my sump pumps off of my solar panel price a d have some type of charger to charge the batter off grid power at night.

I disagree. Active balancer is a must for especially pack that builds from recycle battery. That is my case. I had 200AH packs i built over the year i did not use any balance at all just manual voltmeter. Well they did not last long because of the imbalance and dropping too low situations. Well I wise up and start using the active balance now (capacitor type) and have a wifi camera to remotely monitor. Another benefit is that during use it will continue the active balance to equalize out each bank thus lengthen usage of the whole packs. A good active balance 5A or more must be used NOT the cheapie 1A type. Later on i will add the bms with remote monitor capability.

Hola

Fan cooling the balancer FTW

Active balancing is a good idea. I have the 8s version and it really helps... I wish I had the money to throw away my entire pack and buy all new cells but I don't so that recommendation does not work for me. I think the air you breathe is a bit thinner than the rest of us mere mortals.

6.3v capacitors are not good in my book. We are always taught 2x the voltage. So needs to be 7v caps minimal.

But you really seemed to like the tiny 4s balancer in your other video. Is it a hate love relationship? Anyway.. i dont have a tiny charger to charge cells 1 by 1 as you love so much, so i just ordered a 10$ 4s for using on the cheap lifepo4 byd 12v 250ah for 240$ that i also just ordered. Lets see. Its for my fridge.. I'm tired of power outage. It will be fed by a 450watt panel. No more spoiled food.

I purchased the same balancer... didn't last nearly as long as yours... I can think of better ways to "BURN" $50+ dollars!

Looks like spend the money for grade A cells and top balance from new . worth the extra money.

well you were this time

mine only survived for less than an hour...

Is there a LiFePo replacement for a 12v battery for my van? Would it need cooling/heating to survive under-hood annual temperature swings?

👍👍👍👍

Every active balancer I got went on smoke eventually when charging, so I gave up on them and disconected them.

Or even 4 4S...

It's something but the flat curve makes it not ideal

The idea imo is you don't ever charge or discharge batteries completely, just like in electric cars, that way you get ahead in the long-term

Why did the light stop working? It just did! Electronics/electrics just do that.

All the battery failures I've seen on youtube are almost always because of the balancer not doing its job or kinda working backwards. 1 time I saw a bad cell in a big pack but they also said that they thought it was because the balancer failed

UH OH 4:43....nope that's fine 😅😅 Insert the "got him" meme dude laughin 😄😄 Yeah those balancer boards appear to be poo poo.

if it lasts 30 days then it is good if not , BAD pieces and parts (defective).

I think you done something wrong,cos for me this active balancer works so good,balancing cells perfectly and fast... I would really reccomend those balancers,I use as well 6s balancers to charge battery insted to use balance charger cos it is balancing super accurate