Dead BMS! How to test it? & what's inside my 52V battery pack?
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- Опубликовано: 18 мар 2020
- The battery from my ebike (BBSHD set) had been replaced by the seller, as the previous one had the BMS dead. After the third or fourth charge, this one died as well.
This is 14s5p 52V battery pack, that I am going to crack open and try to test if this is the BMS problem or not. I will also explain the basic principles behind the construction of this battery.
Thanks for watching! 
Хобби
Soooo, did the new BMS fox the issue??
Yes it did indeedd!
@@VRMinde You are sure it fixed the issue. Can we go see ride the electric scooter just to verify?
@@AzraelPercussionNEO mate, if I am telling you it fixed the issue, it fixed the issue. I am not going to spend my time filming a video for you to deal with your trust issues...
@@VRMinde funny
@@VRMindethis didnt fix sh.t dont lie to people😅
Hello because of you I know now how to read the BMS, I would really like to thank you sir, no other video out there explained it like you did, thank you
Man, music for my ears. Thanks for that. I am no expert either, but happy if someone finds it helpful!
Your video was very helpful for my understanding. My bike battery has suddenly dropped in capacity suggesting it is out of balance. I think my next step is to do what you did. Thank you for posting your video.
Thanks for the comment man, glad you found where to start :)
Really well explained. Thank you for your clear tutorial. I too have a BBSHD with 52V shark battery but with 19.2 amp-hr so apparently a few more batteries.
Thanks man. You will have either more cells or higher capacity cells.
Totally excellent Video! Thanks for sharing your experience & knowledge. Not to mention time and effort filming and editing. Thank You! liked & Subscribed!!
Hey mate, very kind! Thanks 🙌
I think if you ask the subreddit r/ebikes some people can give you advice. Also you should post a video or picture of your bike on that subreddit, it’s cool as hell! Keep up the great content
Hi mate, I think I was asking in one of the Reddit forums, but the only guy who replied claimed my voltmeter was possibly wrong :) Anyways, thank you for advice, maybe I have been on the wrong subreddit. I have ordered a more powerful BMS with Bluetooth for about 50 EUR and when it will arrive I will make a video of installing it. Thanks for the nice words! :)
Thanks, I replaced the BMS already on my battery, the new one did not fit properly, so I had to cut some of the case away, and it was working fine for about 1.5 years until today, it turns out the BMS was ok, just the hardness slipped off abit, important to check the voltage of each bank, if voltage is low may need to charge that bank independently, because it may be too low for the BMS to function
I had to add a little box on the battery case as well :)
super super helpful, thanks for the visualization!
Cheers mate!
Thank you. Great video
Hopefully we get to watch U replace the BMS .
No Brakes thanks mate. I am still thinking what to do with this battery pack - replace the bms or disassemble the cells and build a custom battery for xiaomi m365 :) but whatever I will do I will film it :)
The BMS's Ive studied have a feature where they shut down for overdischarge, undervoltage or short. The BMS is reset from this condition by hooking up the charger for a few seconds.
Majority of BMSs have these protections. I purchased the “smart BMS” and I can see change all the parameters in the android app.
Thanks buddy, I'm making a speaker and want to test my BMS board before I put it all together so thanks for the video, have a fun day! ;D
Thanks, you too!
Thx fore your perfectly clear pictures.
What can I say, I am an artist mate :D Thanks for taking the time to leave a comment. This helps!
Great video! How do do you avoid short circuiting the batteries when testing the pins? I wasn’t able to clearly see how you were doing that.
Steve Walley Thanks, I do not make it sure :) I just carefully don’t touch them together :D
Thank you so much for your help! Now to hunt for a new bms
I got one from here: www.lithiumbatterypcb.com/product-category/smart-bms/
still works very well today!
very good video, everything well explained. One question: I have a scooter that uses a 52v 26ah battery that uses 3.6v 14s 10p cells. 10 cells were damaged (water damage). I would like to know if I can change the configuration to 14s 9p with the same controller instead of replacing the cells. and bms
The answer is - it depends. Some BMS are flexible and work on different configurations, some are strictly demmanding the needed amount of series connections.
Probably less hassle with the controller, but 9s will have lower low-end voltage (~28.?V), question is if the controller will work at those voltages or will it just cut it out earlier. Look for controler and BMS manuals if available...
If you open battery packs, please remove all screws, screw drivers and other metal from the table first. Those are classic way to shortcircuit something, when you accidentally drop something like a screwdriver to the wrong place.
Great safety advice!
your amazing, I don't know what to say, thank you ever so so much. your the best
Thanks man a lot!
Thanks, I just went thru this on a power station. I wish they wrote on the side of the pack what the voltage is suppose to be and configuration so you don't have to try and uncover all this or guess. Mine has like 56 cells, registered as 25.4V and the BMS seems to be stopping the unit from turning on. If you plug in the charger it turns on the display but attempting to turn on DC only lasts like 5 seconds and AC didn't even work. If I bypass the BMS everything works.
The consumer these days is not supposed to know anything :D All manufacturers would love us to just buy a new one :)
Facts😭
Great video, thank you! I have a 13s7 battery I cannot fix... the bms was charging all 12 groups to 4.2, and one only got to 3.6v. Turned out it was a bad 18650 element. Now after I replaced the bad element, and put a battery on charge - it charged for some time, and now the charger light is green, and all the groups' voltages are different - the one that was fixed now has 3.8V and others are 4.1 to 4.3v, replugging the charger doesnt help. Is it a bad BMS or it sounds like a bad cell? Thank you!
I do not know how/why did it disbalance like that. You will probably need to separately charge individual cell groups to 4.2. What is not great is that you have cells at 4.3. Your BMS should not let it go more than 4.2, that is an overcharged cell
Wonderful video. Good work.
Thanks mate. Have a nice day
!
thank you for the video, I have a problem with the battery pack, I test the battery direct it has 36v but when I test passing thru the BMS it shows only 18v.
Sounds like BMS is not working as it should 🙄
Hi I'm not sure where to put the negative probe while checking the individual battery wires that go to the BMS I'm not sure where to move the negative probe each time I hope that makes sense thanks in advance
Keep the negative at the battery negative terminal (or the negative of the first series) and then your voltage read should be going up one by one individual wire (for example: 3.7V, 7.4V, 11,1V. etc)
I like how you determined the problem source. Was it easy to order the replacement BMS? What was involved with installing the replacement BMS?
It was easy to order... The biggest problem with reinstalling the new one was it's size :) I have 3d printed extra box and installed it on top of the battery pack. Other than that - just rewiring.
Thank you for the video. I have this question. When diagnosing a battery, there are two errors. The first LED flashes on the first and fifth test. How to reset these errors on the BMS board?
I do not understand what LEDs are you talking about mate 🙄
@@VRMinde ruclips.net/video/vszw6YIm9VY/видео.html
Hi
and thanks for a great video ,
I have a similar problem going on with my wife’s Giant Luv ebike ,I have dismantled the ebike battery case and tested the cells ‘ they are fine so I suspect it’s the BMS , you mentioned replacement but how can I source a new one of the the same specification
Thanks Paul
Great question, what you are looking for is amperage of the BMS to be at least the same as the old one, ammount of series connections to mach your battery pack and then dimensions/size. It is not something I buy very often so it is hard to advice which ones are good... The ones I got from www.lithiumbatterypcb.com/ still lasts on my bikes/scooters. Otherwise - aliexpress. Try nkon.nl if you want one in EU
Great video! Enjoyed the knowledge details. We're you able to replace the BMS? Where did you order it from?
Hi, I did replace it but now I struggle to
remember where did I source the particular one, it’s been a while
Very Informative Video! I have a quick question…my Scooter shuts off at 50% voltage…is that a sign of bad battery?
not necessarily. bms could be kicking in the undervolt protection. it *could be that one cell is draining faster than the others but you need to keep an eye on your range. if you are losing range quickly then time for a refurb & cell swap.
Thank you for this video i have the same problem and battery. Thank you i can fix it now 🙌
The "smart" bluetooth BMS that I have purchased now works perfectly for a while already. It did not fit in the battery case so I had to 3dprint a small bos on top of the original case..
Thank you man!
Hi mate like the video as I have same problem with my battery, did you get a new board and where from as having problems getting one for a 52v 19.2ah battery
Hi man, yes, the new one sorted it out. I had to 3dprint a little box on top of the pack to fit it though as it was a bit bigger than the stock one.
I got it from these guys www.lithiumbatterypcb.com/product/14s-bluetooth-lithium-e-bike-battery-pcb-board-with-30a-constant-charge-and-discharge-current-2/
Works flawlessly for more than a year now!
I am in the same predicament here. I'm not really an electronic guy but I knew the basic.
I already rebuild my battery pack and then I just learn my BMS is faulty. so .. I have to find someone who is willing to sell their faulty battery and gamble over for a donor board haha
thank you for the advices ! I have a problem on my mercane, sometimes is cutting off , and i've found out that the battery voltage drops from 50V to 6V. Playing with the wires from esc , motor and Dc imput, when unpluging the wire from handlebar mother board , the voltage increases slow to 50. I think that in my case , the bms protection kicks in. I've checked the battery voltage, and I have 50V on the battery,and 46 after bms, is it normal ?! Great video!
I am not sure I understand all of your story, but If you have different voltage on battery ends than on the BMS exit - your BMS is doing something wrong :) and if the difference is 4V it is way too big
Instablaster.
Thanks for this value information
Glad it was helpful!
Hey there! I have exactly same problem, new battery with samsung cells wrong voltage at discharge port but correct voltage before BMS. Did you replace BMS? did you make video? please post link, many thanks!
Hi, I did replace the BMS, but I did not make a video about it as far as I remember :) And it helped. Sorry for the late reply, youtube is no longer notifying me about the comments lately and I do not know why!
Hi mate, I think I have a similar problem. I own a 7s BMS that has a B- and P- that connect to the Battery negative and Pack negative respectfully with Battery positive being common for both.
And +,1,2,3,4,5,6 that connect to the 7 series.
Can you tell me how to test that one?
Hi, it is the same priciple, measure directly on the pack and then check if you get the same out of bms 🤷🏻♂️
my 48v 13s battery on a ebike, cuts off screen volt read from 50.8 then 36v then 28v then screen cuts out restarts reads 28 then jumpos up to 50.6v then drops again, i mesured each pac 4.23v but one in the middle reads 3.80v i have tryed chargig it to get it back up but dosnt get much higher, pac or BMS fult?
If you have cells that do not charge up - there are definitely bad cells. BMS might be fine. The question is why do you have one bad pack? Can be simply 1 faulty cell. Anyways you will have to replace the wrong cells first and take it from there... annoying as F...
Since I started using Lithium batteries, I realise the BMS is their major weakness. In fact, I real lost confidence in them, because you never know when it could suddenly fail out of the blue.
Yes it can, but in like 10 years I had 2 of them failing in the way that it “does not work any more”. Without one it is easy to fail in a way that everything burns down
hi hi have 36v battery the charging fuse missing f1 do u know what size it would be its an aovo one shorted neg an pos wires out put lead shows 24v but on the bank its is 41v
Hey mate. When riding my 1000W, 48V, 15Ah Ebike (PAS 4 or 5) the power will just cut out then it’s erractic/little power etc. Removal/return of battery on bike can fix issue but it usually returns. To try to keep my description of issue short but still clear, apart from that, the problem is very intermittent and inconsistent/unpredictable. Very frustrating!! Is this the same working issue you were experiencing? I suspect a BMS reset will fix?? Problem did not exist until using bike after repairing the severed wire/s supplying motor that resulted in no power to bike and an “Érror 07”. Thought worth mentioning. Planning to buy a Multimeter today to test.
I had similar power-offs on my BBSHD with the stock controller. Can't remember what error code would it give now... Replacement of the controller helped.
It is always worth checking the voltage of each series to know if there is any disbalance in the charge levels or not.
Thank you for your time... Cud you have bypassed or not replace the bms and just connect the battery directly to the motor? Will the motor work, will it also still charge?
You can absolutely run it without the BMS, but you need to make sure you: Do not overcharge the pack, do not over-discharge the pack, same for individual cells. The chargers might not be accurate at their voltage. And Monitoring when it is getting over-discharged can be annoying. Overcharging or over-discharging a cell can lead to a thermal runaway and fire...
if you want to run without a BMS then you should have a balancing port and a charging port at hand. The charger will cost as much as a brand new battery (or more), but you still can run it that way. I advise you to just buy a new BMS for 10-15 euros
Hello ,thank you for your video the explanation was pretty good , I got a problem with my e bike battery it’s a 48v 34ah , when I put it for charge it takes 15 minutes and the charger show the green light means it’s full , I changed the charger but nothing new ,I don’t know if it can simply repair or I have to buy a new one
You need to see the voltages of the cell groups. But either go and study “diy li-ion battery build” until you understand that yourself or bring jt to someone who repairs the batteries instead. You will pay for their work and knowledge and they will fix it for you :) these batteries can explode or burn down a house
@@VRMinde you want to say the problem is in the cells thanks reagards
@@Anti-P I assume you have a disbalanced/problematic cell. It probably has voltage way off from other cells and BMS does not let overcharge or over-discharge the individual cell groups. So if your one cell group is at 4.1V and other at 3.5 - you can’t either fully charge or fully discharge the full pack. If you can measure voltages of each series groups you would know if that is true or not :)
I have ebike model MATE X-750W.Battery fail-
Ithink charge to 43V but when turn key to ignition position voltage on output connector 0V.
Problem with BMS?
WHAT can i do?Where buy or fix it?
Can be BMS, can be the “ignition key”. It should not charge to 43v, I assume it is a 10s pack and if yes it should never ever be more than 42v (4.2v X series). Try and search who is making/fixing batteries around you, they should be able to help.
I have a 52v 17.5ah battery for an ebike I'm building. The battery has a 30A bms and the bike has a 1500w motor. Will these work together? If not, what can I do to protect the battery? Should I get a new battery or can I change the BMS
52V should be 14s pack. Voltage will be from 46.2 to 58.8. If you stay at let’s say 28 amps you should generate 1293-1646W, depending how much charge is left. Which makes it reasonable to have 1500W motor. You should limit your power/amperage on your motor controller to like 28a max and your components should be just fine, if the pack is built with enough Ni between the series connections. If you want to use more power on your bike you will definitelly need another BMS or even battery. Your battery pack might be build for more or for less amps, depending how are the cells aranged and connected in series 🙄
Mate my new Hitway bk6 just died on me I got 06 ( under voltage) then 10 (display cable) error codes. No bugger will repair anything but Bosch. Will you have a look at for me please?
Hi, not doing repairs for others mate...
is the battery pack case a HAILONG?
How do you find the correct BMS? Mine has a power switch with power level on the case, and it also has 2 extra wires which provide battery level to the LCD display. Seems my BMS is extra functionality? Its from iZip BL17 battery pack.
It is not simple to find “the right one”… i have not purchased too many of them… so do not have a sure answer :)
Could you explain how you test the cells? Which wires are you probing?
Individual cells? You have to test them individually, there is no way around. I am not sure if I can explain better than showing in the video mate 🙄
I enjoyed this video and your accent
Thanks man for the support!
Buy /build new battery or add new BMS dilemma. Ebikes are brilliant, till they break. Good luck.
Colin Brunton exactly! Unfortunately my experience with ebike was not the best by far :D meanwhile scooters are performing really well
My battery losing range and cutting out now had 50 amps on phaserunner running threw it got hot at times help
You will have to check the cell groups individually for disbalance. 50amps can be way too much, depending what cells and how the pack was built 🤷🏻♂️ if you demanded more from some cells than they could give you - there is a good chance they are dead 🤷🏻♂️
I have a similar issue except when I have it plugged in, the power isn't shutting down but it's stopping me from drawing any current when I turn the throttle. It'll work when full but later on and randomly it cuts out more and more at the throttle. I'm using other packs at the moment that all work fine. I just did what you did and checked each series and they all have exactly the same voltage. All 3.94v. Is this still likely a BMS issue? Cause mine is still getting perfect power, unlike yours. Just the throttle cut issue 🤔?
Clinton Boucheix did you check the welded contacts on cells? Sometimes there is a loose contact that gets disconnected on vibrations when riding. I cannot think of something else now at least 🙄
@@VRMinde everything is solid. I checked each one. I even checked for continuity with all of the charge/discharge black wires on the bms. As I said, I'm getting full signal. The voltage is reading it's full capacity, even on my throttle's battery indicator (I have the type that shows the actual voltage of the pack) it's showing the full packs voltage status. It even charges up fully just fine. I'm stumped.
Clinton Boucheix these are the worst type of defects that happen at random. Then one of the ways of troubleshooting is to try replacing one component at a time and see if the issue is gone.
I also assume that you have tried to lift the welded contacts with some tool, not only checked the continuity?
If you say it works with other packs, then at least you know it is not a controllers’ or throttles’ or wirings’ fault 🙄
Likes and thanks for the video. good work
Thanks man!
Realy informetive vid. thanks, Same probs, hear, Still no Luck Though....
Damn. For me the new bms solved the issue. Hope you find the solution soon
How am I testing the pins? put the negative to the main negative and then the ppositive to each pin, one at a time?
If you test like you have described - your voltages will be adding up (f.e. You will see 4.05, 8.1, 11.16, etc). You can also measure in between two pins that are next to each other, then you will see the voltage of each series group (4.05, 4.05, 4.05, ….). Just be careful and do not touch the pins together to avoid fireworks :)
@@VRMinde thank you much
Where are testing the leads at on second test exactly ?
I am testing each series group of cells. So on the "balancing wires" that are connected between the each individual series group
Hello, I have a new trotnet that suddenly stops and does not work unless I put the charger and unplug it and it works again.
When I checked the 52V battery, I found that it was low at 42V, and when the charger was put in and unplugged, it returned to 54v or more depending on the charge every time when it stopped working
My question is, is it necessary to replace the bms charging part to solve this problem?
Hi, sorry to hear. it can be either bms or a bad cell/cells. You will need someone who can take it apart and identify the problem 🤷🏻♂️
@@VRMinde Last night, I disassembled the battery and measured each cell and found that they all have the same measurement of 9.3V and the battery is 42V. I measured the negative wire coming from the battery with the wire (- p) it gives a measurement of -9V and when measuring the end of the battery with the negative and positive directly, I get 51V and when the charger is placed and disconnected in a moment, the measurement becomes approximately 57 V. I think the problem is from bms
After watching your video and others, it's obvious that the BMS is the problem with my battery. Problem is, I don't know where to get a replacement or how to make sure I am getting the correct one. Ca you provide any guidance?
It is a tough one to be honest.
I have only bought BMS twice myself.
You need to consider only several things: 1. Amperage, depending on how many watts you want to draw from your pack, your BMS should be able to survive it, and I would add a bit. If I plan 50a draw I would go with 75-100A BMS.
2. Number of cells in series. 3. With or without charge leads (some batteries charge through the discharge lead and some have extra charging ones, that is defined by the type of BMS). 4. Do you want to connect to your BMS via bluetooth. “smart BMS” will allow that.
I got myself one from here: www.lithiumbatterypcb.com/product-category/smart-bms/
It has been about a year or more and it is still going strong. It is ctually doing a great job at balancing cells. But it did not fit in the same case as it was much bigger than the stock one.
Otherwise, get something from aliexpress, read reviews and hope for the best :)
Someone told me that good BMS will likely cost 1$ per 1A, but I am not sure if that is a great way to assess it :)
Amazon carries them..I have a 48v yet passed the bms it reads 19.5. this is.why I watched your video. I believe you helped my decision for a new bms. Thanks
Does anyone know how the red ON/OFF switch on the battery works? Mine is connected to the BMS, but it does nothing. The battery always give power. Is it BMS fault?
It is a bit hard to understand your question without having any context mate
Ye, my battery was stuck in the on position, so I removed the switch, and the led display circuit board
Bypass the discharge on the bms . I kept having the same problem till I disconnected it the balance part of the bmms still works it can't working for two thousand miles and only recently burned down which now I'm waiting for a newbie bms you just have to make sure that you turn the bike off once the battery goes down to 20%
That is almost as running the pack without one :)
@@VRMinde my board runs better without discharge maybe not better than a more expensive one but definitely better than the bs ones it come with and I only did this after seeing several people with alot more knowledgeable than me do this on purpose on brand new bms but you are right better with for safety and probably longevity of batteries
my hailong battery says its fully charged all green dots on the battery. but on my display its showing 38.9v its a 48v battery ive had it in my bike for 6months. theres also like a electic cliking noise coming from battery when turned on. can anyone help me surely the cells are not dead ?
You will have to disassemble the pack and at least measure voltages of series groups. If one will have weird voltage -
It has damaged cells. Needs removing them and replacing..
Hi , My battery was perfect till today when I tried to turned it on and it does not . it was fully charged last time and when I tried to charge it does not charge as well . I opened the battery case and can you tell me how to check if the cells or faulty or bms ? Thanks
Well, first of all you need to measure the voltage coming out of your battery. “Does not turn on” probably means your controller is not turning on, is there some voltage on the wires coming out of the battery?
If there is no/low voltage, then you need to measure the voltage between the main positive and negative terminals of the battery pack (before the BMS). If you have normal voltage before the BMS and no voltage after it - it is probably BMs’s fault
@@VRMinde Thanks for your reply . there is not any voltage on the cable coming out of the battery . how to find a main+ and main- before the bms ? please help I am not expert .
@@mos.f5810 i suggest you watch some video on how to build li-ion battery. That will give you some understanding where those are. I cant explain in a comment
I made 12v 8mah battery for my bike and the bms not charging, even i had changed the bms again the result is same. What will b the reason??
Man, I have no idea why, probably you have connected something wrong?
Hi, i bough a 36V21ah battery pack for ebike, it came with a strange odour, but i though it was because battery was brand new, i made about 400 kilometers, battery seems work well, but one year later, strange odour is still here (headache after inhalate this odour (no smoke,nothing anormal, just odour))
What do you think about it ?
never had "smelly" batteries :D Don't even know what could be the reason mate...
@@VRMinde maybe a leak, i'll try to see it with customer, thanks for your answer
@@zeubilamouche2896 if you had a damaged cell your battery capacity would be miserable 🙄 but you will only know for sure when you open it
@@VRMinde the capacity seems normal, the battery restores the advertised capacity well, that's why I don't understand why there is a strange smell
I'm afraid to open it now x)
good work I have 16 s 24 amps 48 volts lifepo4 battery when it goes to 50 volts the lamp headlight horn does not work at all bms turns off it is charging until 53.1 and not charger is it the problem with the bms or the batteries please help motor contoroller 500 watt motor 249 max 1200 wattscontoroller 42.+52+1 nominal voltage 48 60 volts contoroller 30+1 ampere 500 watt contoroller lifepo4 16s battery shuts itself down to 50 volts and charges in 1.5 hours, what is the reason, thank you video informative : greetings from Turkey)
Hi mate, it is a bit hard to understand this one very long sentence :D
If you BMS cuts off charge before the battery is full you need to find out what are the voltages of individual series groups. Potentially one group will be at max charge level, while others are not. It can be because of the faulty battery cell.
@@VRMinde It's a really nice video, you can be a marvel of technology, thank you very much, good work.👏👏
@@Beyinlocked haha thanks mate! hope it helps!
@@VRMinde 48 lifepo4 volts fully charged 53 volts 50 volts to 53 volts It charges in 1.5 hours Even phones with lifepo batteries do not charge that fast in 1.5 hours charger 24 amps 3 amps amazing 3 volts It takes 10 km maximum in 1.5 hours problem battery or controller? :)
hey very intersting, did you have any "crash or bump" before it stop working?
i put my new bike together, tested in the room , it worked, than went out and first throttle did not work, so i tested different controllers, not working, but when i put the charger on while battery on the bike it works.....
so i checked the motor work
controller works,
throttle worls, cables work, seems like the battery doesnt give any power
even if i want to check the battery status, it gives no signal, only with charger in it...
not that I recall mate. In case your battery contact disconnected from a little bump or so, it would have happened anyways. I ride my bike as a "propper mtb", so it falls, bumps, sometimes flips and still works :)
@@VRMinde hey i found the error, i modded to a bigger controller , so the 30 a fuse of the battery burnt
@@matthiasdornblut2727 that's easy :) congrats!
@@VRMinde do you think installig a bigger fuse like 35amps would work, if i keep an eye of the battery temp?
@@matthiasdornblut2727 someone who put that fuse in, probably put it with the reason - to protect either battery cell connections, cells or BMS. If you install larger and draw more amps - you will burn something else than the fuse. Install another original amp fuse and keep an eye :)
Hi i have a 48volt and i charge it to 54.6. Now the battery shuts down at 46volts, 1/2 the charge with a error code from bike. The bike turns on again at 46volts just to cut off a few minutes later. Can it be the bms? Or defective cells
What does the error code say?
48v pack should be 13s? Then if it turns of at 46v average voltage per cell will be around 3.5v.
There is a chance that your pack might be disbalanced/have bad cells. Let’s say you see 46V, average is 3.5v per cell, but there might be cells that are at 3.2 or 3.1, while others are at higher voltages. You accelerate, voltage drops and if some cell reaches minimum set voltage BMS will shut down the pack.
You need to first find the voltages per every cell group when it is at 46V.
Sorry for getting back late the error code is E0006...its a low voltage code. Now how can i balance my battery, 46 volts with error code. It charges to full...can it be defective?
@@otto99able16 I do not think you can guess it. You need to measure the voltages of every series group of cells. If it is unbalanced a lot - probably some cells will be defective and won’t keep balanced.
Can I connect the battery directly to the hover board, bypassing the BMS?
You can bypass the bms, but then you need to make sure you never overcharge the pack or overdischarge or loose the cell balance, or have a bad cell etc. :)
There are people who prefer no BMS, I am not one of them
I heard you could bypass the BMS….but leave the charging port’ basically only using the BMS when you charge the battery.
@@ebperformance8436 you can, people do that when they have let’s say 10A BMS, but want to draw more amps from the battery pack. It won’t stop you from discharging the battery too much then, etc.
What caused the bms to fail? I just had one go on me as Well🤦battery is fine but no power through bms
Have no idea what could be the cause 🤷🏻♂️
I went for a cheaper and 7s 20a
And I guess youbget what you pay for. Thanks for the vid and the reply!
Have a good one ✌
@@thomasholland4313 i replaced with some expensive bms and it works since :) thanks man and have a nice weekend!
If you build No bms only hobby charger. Bms suck
Did you find a new 14s BMS , what was the price ?
I did, don’t remember now… look here www.lithiumbatterypcb.com/product-category/smart-bms/
How frustrating that is. I was such enjoying my new Kugoo m4 pro. It lasted 3 charges and now in ton't charge which I suspect is this stupid BMS
thing broke/failed
Oh I know that feeling man. I hope you can get that fixed soon and go riding again
Hi, excuse my english,
Do you think the BMS is dead because you have 20V between the negative of the BMS and the positive of the battery when the button is OFF? I think I have the same problem ... have you solved your problem? : D
Hi, if you measure on the battery directly and have different voltage (let’s say 48v or so) - probably bms is dead. If you also have 20v on the battery terminals (before the bms) - you have either loose contacts or dead cells. I have replaced my bms to a new one and that solved the problem
do i use common or separate type BMS for ebike (72v 20s 3p 80A continuous)?
What do you mean by separate/common BMC? (BMS I guess? But what is separate/common?)
@@VRMinde
Sorry I meant bms,
2 or 3 wire bms
(Same or separate port)
Separate port- 3 wires, charge port and discharge from different ports
Common - 2 wire, charge and dischatge from the same port
Thx for answering
Mat ddd I am not an expert. But as far as I have seen many 2 wire BMSs have one potential issue: for example one of your cell reaches lower than min V. 2 wire BMS will disconnect the load to protect the battery, but it will also disconnect you the opportunity to charge it. Same with overcharging - if you charge the pack and manage to overcharge it - 2wire BMS will disconnect not only charging, but also the load.
3 wire BMS will not have this issue.
I believe there are also 2 wire BMSs that have the ability to disconnect load while keeping the charge enabled (if they have double FETs), but there are not many of those. As I said I am not an expert on this, that was just my opinion 🙄 is there a big price difference?
BTW, what kind of a beast are you building with 72v battery? 😳😳😳
Mate, it's a bit funny to hear you say "I need to be really careful" with that cup of tea close to the battery 😁
Just joking, it wouldn't be a (big) problem.
Thanks for the video
😂 what could go wrong 🙈
well I think the battery goes through te BMS when discharging or powering the load. Is that correct?
If that's the case then the BMS must have fried its MOSFETs. The purpose of the mosfets is to cut off power if it senses that the load is too large for the battery.
first check that your load has no short circuits
then next, check for physical manifestations of mosfet failures
if there is none, you can purchasea cheap BMS to replace your existing one, or
if you'd like
if you can, try to test the mosfets yourself. A lot of videos explain how to test this, but for the sake of time, better replace the BMS.
Thanks
Thanking you mate 🙌
Sir :
If anyline of series lines is damaged .. the + and - of battery gives ..let's say 45v .
May be in this case the BMS gives ZERO volts , when it ( BMS ) is NOT damaged.but we will take a wrong result by accusing BMS!
Could this case happen ???
But when you measure series by series you would notice it 🙄
@@VRMinde
Sure . So we should measure lines one by one I think to be sure that BMS is not failed .. thanks alot 😍
Hi what will happen if connect the battery to me controller if the bms is not working
Iam afraid to burn the connect
Do u have any idea?
The seller tell me to check my bms
If are in the 🇬🇧
Do u have any store can check the bms for me ?
Thanks
Hi mate, I am not in UK I can’t help you.
BMS ir protecting your battery, it has not much to do with your controller.
You can check the voltage if it is correct before connecting anything
@@VRMinde hi thanks for your reply
the Voltage is zero
I checked the Voltage of xt60 not bms
Is it dangerous if I use the battery if the bms is destroyed 🤔
Can I check the bms without open the battery
I can charge The battery normally and the usp in the battery works
But last time I connected 2 battery to one controller so the controller is burned after that I connected one battery to the same controller something wrong in the battery or in the controller i don't known
Tomorrow I will receive a new controller wich cost me around $65
I am afraid to connect to the controller burned the controller again what do you think
Thanks for your time
@@user-go7ej7hx2k if your battery gives 0 then there is either a physical problem in cells/contacts etc and BMS is shutting it down or faulty BMS.
You will not find out the problem without disassembling it. Do not connect faulty battery to anything and make sure to keep it in a safe place until you find someone who can open and check it for you.
Lithium batteries are dangerous and can cause serious fire mate, be careful.
If you don’t have basic understanding in electric circuits - save yourself time and money and find someone who will fix it for you
@@VRMinde thanks alot
Yes it gives zero on xt60 connector
The problem is all stores refused to touch it because i bought the battery from China
And it is still new I charged to full and looks fine
Where should I test the Voltage do mean I have to open to check it or I can test from outside I hope I can share a picture with you to explain more to you but my English didn't help me alot 😁
My battery has 76v when I test it but the bms under no load only has 12v. Is that right? its a daly bms.
If BMS only delivers 12v it is definitely not right. Check out all the series cables on the bms and carefully measure voltages between the series groups. I assume you have a 20s pack?
@@VRMinde yes 20s 8p. Batman of Inglewood suggested that the bms needs to be activated with the charger.
@@felonebike9859 if it is a freshly connected BMS that could be the case 🙄 before you connect anything though be sure you wired the balance wires in correct order. The voltage should stack-up by the value of the cell group (for example 3.7, 7.4, 11,1 etc.) if you measure in between them. Just don’t shorten them when measuring :)
@@VRMinde I checked and its all good. The voltage goes up on everyone. I'm about to wire the charger in. Probably take 2 hours. I'll give you an update when I finish. Thanks for your help!
@@felonebike9859 if this is charge-enable issue 5mins on charger should be enough to check if you get correct voltage out. Anyways best of luck mate, let me know
i have a btrpower lifepo4 battery, it reads 37v (36v battery) which is fine, but when i turn on the scooter, and i volt meter the battery, it says 1.2v, and wont power the scooter.. is it the bms? my SLA's power it fine... hate to ask but literally cant find anyone else who knows what they are doing. controller is spd 36900a from electricscooterparts... thanks in advance
anything heating up? (short circuit?)
@@VRMinde not at all, all the connections are good and clean with no ground outs or anything. Volt meter reads 37.54v then flip the on switch and 1.224v. The SLAs work just fine when I connect them.
@@joedirtthe3rd in order to understand if that is bms issue or not you need to measure voltages separately from bms and on the bms output. If your voltage without bms also drops so low - there must be huge resistance somewhere, like short circuit kind of resistance 🙄 should be some smoke or heat at least :D probably not the case. Where do you measure the voltage?
@@VRMinde thanks! I’ll see what I can do as the battery is all nice and heat shrinked… I measured the voltage from the discharge leads and also the charge leads. But there is absolutely no sparks, heat, smoke or anything. Just the moment I turn the system on it reads low. And that was checking connection between batteries and controller, everything from controller to motor is 0 volts,
@@joedirtthe3rd did you figure it out?
Good!
Thanks bro!
Seems to be common problem with ebikes I currently have battery lasted less than 30 miles.
I replaced it with an more expensive bms and it lasts for a long time now
Where's the new bms install video?
Amm it has not been made :D
Ignore the idiots complaining about the music, the most important part of the video is fine and comprehensible.
Thanks, that confirm that my BMS is dead, i'll order a new one.
I still appreciate all the feedback.. the video is old now, I try to improve what I do :) Thanks mate!
@@VRMinde You fixed my bike for 20€ and an afternoon, so thanks to you !
@@SaitoGray this is the best feedback i could ever get! :) happy for you mate
Gas is better, BMS shuts off when one cell goes down....it turns off for safety but when you replace faulty cells... you will need a new bms once it turns off to save the battery from overheating, the bms is TOAST at that point
get rid of the bms all together, all you need is fuse and cell log or similar.
Put the multi-pin connectors on outside of pack and just measure/balance the cells when needed.
I personally leave cells exposed without cover, that way I can feel heat of cells, first sign of bad cell is heating, you can catch a bad cell pretty early just by feeling the cells after a ride or during charging.
Keep life simple!
There are many people that think your way, I know, and I can follow the logic. But I do not find it "simple" at all. I like it when BMS does all that for me and I can ride until my battery goes off... And charge until... until I remember to take it off the charger :D
I have not had too many bad experiences with BMS over many years.
@@VRMinde your logic is sound also
When the fox doesn't reach the cheese, he says it smells. He only wants it cheap and is not able to produce competitively, not even to repair it because it is simply built.

Is this some sort of a lesson? I am not smart enough to understand 🤷🏻♂️
Does it need a bms?-
Nothing needs a bms if you want to track your battery state manually. However bms protects from overdischarging, overchargig, cut-offs at short circuits, tracks temperatures of the pack, balances cells, tracks voltages of the cell groups etc etc.
I have a battery that “dies” when installed onto my ebike when torque is applied. The power indicator green lights go dark . When I test the voltage , it is between 5 and 6 volts. When I plug this battery into the charger for 1 second , the green lights turn on indicating full power , the voltage is now 51ish volts.
What is causing the circuits to trip?
Can be a dead cell/cell group.
@@VRMinde I think a bad bms. The voltage is 51 v after plugged in the charger
@@linusleblanc6348 so the bad cell can charge up but be unable to hold the charge. You can just check all the cell groups and either confirm this or dismiss
@@VRMinde the voltage is 51v
@@linusleblanc6348 you are telling me the voltage of entire pack, did you measure every cell group separately? Both when it is “fully charged” and “empty”
i did like this video
Thank you for the feedback mate!
@@VRMinde keep going!!
You were blocking the shot with your hand when you said be careful. Can't see what to be careful of. the rest of the video was great
Be careful not to touch in between the two pins :)
Lithuania? :D
I am Lithuanian but I have been living in Denmark for a long time...
checking voltage with no load is not a good test
bad battery show often good voltage
but they do not have amp anymore
so under load voltage go down and bms cut off power to ebike
I can’t agree mate. Only because I have never seen a bad cell showing “good voltage” without load 🙄 the only scenario this is possible is when you have a bad connection somewhere, like a failed spot-weld on a cell that is barely touching.
Failed cell will 99.99% of the time show wrong voltages, won’t be able to fully charge with the rest of the pack and so on. I will keep that 0.01% to say “it might be possible” :)
@@VRMinde that why there tools that put load on the cel to give you amph
cheap old cel have good volt but very low amp
you should of put a fuse jumper wire from pack to bike and monitor voltage at battery will giving trottle with bike supended above ground and watch if there voltage drop if there cel going low cut off point
and monitor with amp clamp
that can be a good advice for further analysis if I would not have found what was wrong, thanks!@@danman9017
6:27-6:45 😂🤣
;)
Why elevator music???
Honestly, can’t remember now after 9 months, probably thought it would work well :) is it annoying?
@@VRMinde Fine video so it's ok
Not really testing the BMS are you... your just checking the cells, the BMS issues is not resolved, change the title?
OK, I can see your point of view. But at the same time I could argue with you (I am simply not going to :) ). Therefore, I will not change the title. Thanks for your comment anyways.
A lot of chinese bms are faulty. Do not use these.
It came in with a battery pack. I am not buying battery packs any more :)
Don't need the background music
oh well... now it is already there.. :/
Done many times, no worth it. Once after replacing the BMS, the battery blew up while riding a bike, it means it's time to replace it, don't bother with it because it may explode.
I use the same pack after 1.5 or is it already 2 years now…
Also in my case this pack was almost new when the BMS failed
I don't use bms never a problem. Use matching cells
Of course, it is always a way to go. But for me not THE way to go. I have 0 wish to manually check not to over-charge, not to over-discharge, and manually balance the cells. My controller even uses BMS temperature to cut-off in case of over-temperature. I think it is way less hassle and safer.
I was 666👍🤔😳
667 ha
Evil! 😈
Didnt like the video. The camera angle didnt show how i can test the individual pins.
Thanks for the feedback!