The *ULTIMATE* BMS Guide
ฝัง
- เผยแพร่เมื่อ 4 มิ.ย. 2024
- Everything you ever wanted to know about BMS's and more
-What is a BMS
-Different Types of BMS
-Bypass vs discharge
-What do those ports do?
-Safety
-worked installation example
TIME STAMPS
01:00 - WHAT IS A BMS?
01:55 - BYPASS V DISCHARGE BMS
04:00 - BMS DIFFERENCES
05:00 - WIRING GUIDE
06:15 - COMMON CHARGE AND DISCHARGE PORTS
08:50 - BALANCE HARNESS WIRING
14:40 - DEALING WITH CROSSING BALANCE WIRES
16:18 - COMPLETED BALANCE HARNESS
16:34 - A NOTE ON FLEX
16:50 - TESTING THE BALANCE HARNESS
19:20 - WIRING THE B- AND C-
26:32 - BLOOPERS!
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#BMS #howto #guide
Hey Lee, from someone who's very new to the Esk8 scene, I find your videos really educational as I really want to build my own mountain board. Hopefully once I've watch all of these vids I might be able to do so haha. Please continue to keep up these videos your doing a great job for the esk8 community. Well done 👍
Hey brother! Thank you very much! I'm so glad you are learning some stuff! I'll continue as messages like this get me so hyped!
Just a word of caution. Not sure if it was mentioned in the video but just beware of over-discharging your cells, so needless to say, keep an eye on your voltage. Bypassing the BMS will disable your low voltage cutoff protection.
So your electric skateboard will just ride till it breaks?
Good info
@@juicyboi2923 Yes it will. Once the batteries are discharged beyond a healthy 2.6v per cell, they won't retain the same charging capacity anymore.
Man I absolutely love the music in the background! Keep up the awesome videos Lee!
As an American I heard “30” on those balance wires. Took me a good 2 minutes to realize you actually said “13”...😑. Great video man! Super helpful for my build.
My guy I'm just starting a serious college project regarding battery packs and you literally just helped me to solve all my doubts about what to do coming up next with BMS connections. Thanks a lot Lee you're amazing!
Now that you learned some more does this video still hold up?
Excellent explanation thanks mate.
I have been trying to understand the discharge side of BMS fo high current discharge applications for a long time and found endlessly conflicting info on the net. The info on bypassing BMS discharge control on high current draw applications was the missing piece of my puzzle.
Legend!
Thanks! Assembled my first battery with this guide, works perfectly!
Well done brother! I'm really happy that this helped!
Man am I thankful I just stumbled upon this video. I wired up my 40a BMS today and wired P- I’ll take that off. Makes total sense now.
No worries bro, glad it helped you!
@@LeeWright I'm rebuilding a ninebot ptr battery pack, its 2 packs 15s2p each pack, factory was 30 amp bms can I replace them with 60 amp bms?
Where can I purchase quality BMS’s?
Pretty handy video with a lot of gold nuggets of info there. Your batteries are a work of art. I will be after some improvements to my battery and BMS in the Icarus when the right VESCs come along.
Thank you simon!
Fantastic video mate -admirable attention to detail! I normally don't use Patreon but you're a top guy making top content, so I had to. I am not going to attempt wiring a BMS or making a battery pack myself, I just enjoyed understanding the logic/procedure/practices and filling some blanks. But what's most important is that you help educate/bring new DIY builders to the scene, keep up the great work!
Hey man! That's awesome! Thank you for helping me out! In return you are now getting behind the scenes access, hope you will enjoy being part of the patreon crew! I just want to share knowledge and help people understand how to do this crazy esk8 building stuff - knowledge should be shared not hoarded.
What a GREAT Video!! Exactly what I was looking for. Thank you so much!
Just found your channel, really like your approach to building batteries and putting extra thought into making it as safe as possible. I'm more ebike as never been able to balance on a skateboard but have subscribed to help improve my own battery building. oh and keep the chilled background music
Hey John, that's super cool of you to say. I think it's important to make them as safe as possible, bloody bombs haha
Great vid mate! Had an issue with my battery upgrade on my Evolve GT and decided to replace the ESC and BMS with new stuff. Was quite boggled when it came to picking a BMS. Went with a 40a smart BMS(looks similar to yours) but didn't realise I didn't have to use for discharge, only had the stock BMS to go off and didn't have a clue. So the original is actually wired for discharge then I guess.. The charge only seems so much more simple. 🤔 Thanks for all the info. It all makes alot more sense now.
You are most welcome mate!
Your videos always come perfectly in time, so i don't have to annoy you asking how to xD
Hehe! Glad you will find this useful@
Great video brother. Appreciate the effort and it was super informational. Gonna use it for my build.
Good advice with the smart BMS and the fish, kepton tape! Keep up the great work. Thx a lot
Getting super nerdy! I'm loving the education 👍
Thanks Tim! Super nerdy! 🤓
Thanks mate, I just got exactly what I need for the charging stuff.
Very well done. Awesome editing or the video!
you teach us so much, Thank U Lee
im new to this, have some good electrical knowledge but as i say im fairly new this one. just got my first bms, nickel strips and spacer system for a 36v ebike battery for use on my schwinn stingray chopper. gonna take my time on this build as i want to do it right. currently get about 12 miles from the bike based on a 36v brushless 500w hub. plenty of torque for acceleration up to 18mph. subed to ur channel and realy enjoy the videos. great knowledge
Sounds like a great build dude!
Best BMS video on TH-cam, nice 👍
Thank you!
This is such a helpful video! I'm looking to build my first battery pack (10s2p) with 21700 cells. Are there any other considerations which are needed when using these cells in terms of a BMS? Thanks!
Thanks 😁 I just ordered one of your smart BMS. Molicel p42, 12s. For my kaly deck and enclosure. It had trouble finding a Daly. Was watching this video and heard you say you had one 😁 thanks again and have a great day. Esk8 Freedom. Keep up the good work
No worries dude! Will be in the mail tomorrow!
@@LeeWright awesome thanks 😁 hey you wouldn't happen to know where I could get one of those 12s4p flexible PCB from, would you? I know direlect robot supplies used to have them but all gone and not much coming up in Google search. Maybe some of those 4p PCB would help me out 😉 I ordered the flipsky portable spot welder. Will be my first time welding batteries together. I have done a couple buss bar packs though 😉
Arrived today 😁 thank you very much 😁 super speedy. Only piece I'm waiting on is the flipsky portable spot welder. Maybe tomorrow. Thanks again and keep up the good work
I love the details. Thanks 🤘
Nice explanation, i learned things 👌
Thanks man 👨
amazing tutorial thanks bro!!
Thank you for sharing your ideas with us I’m about to start looking for a 4s BMS but I need at least 300 amps and Bluetooth what would you recommend keep up the good work and stay safe
Well done, thank you!
Great video. You you make a video where you start from the beginning on how pack the 4P, spot weld, and daisy chain the cells?
I have something similar on my channel already bro 👍
Great vids, Lee!
I’m high in the mountains (off-grid. Of course), and I’m part-way through making a light. Checked the self-discharge rates, and it looks like I can use 96- 18650 cells, and a 3W,3v CREE LED. Any chance of a tutorial on how to assemble this? What BMS is needed, etc..
Thanks!
- “Mad” Max Speedwell
bloopers is my fav part but im going to buy that bms :) (12s)
Awesome! Yeah the bloopers is funny! 😄
Great video learnt heaps
Lee. You the man. I learned a lot about BMS seems I thought I knew. Lol. Almost as funny as you video ending. I'll be getting with you about a 12s battery pack built by you. Blind I am. It would be very dangerous if I were to try and build a big battery, or a battery of any sort for that matter. Hope you'd be intrested in building one for sale.
Keep them vids coming. Good stuff.
Hey bro you are welcome! Yes we build batteries for sale no probs
@@LeeWright thank you bro. Now to get my money right. These times has my money all funny. Let me know a price for 12s5p 21700 cell battery pack. It's going on a drop down board but it's 41.5 inch long at 10 inch wide. Should be enough room to accommodate that big ol battery pack. Oh. Might need a vesc too. Again, thank you Lee. Safe riding mon frère.
Good vid ,well explained 👍,(ive done exactly what youve done but when connecting b- to the bms the bms blew!very annoying anyway the only thing i can think of was the last bms's harness had the black lead looped into the next port on the harness and then continued as normal,would that have been why the bms blew or any other suggestions would be greatful)keep in mind i double checked and taped down properly before harness or main b- was connected 👍
VERY INFORMATIVE thank you, i do have a question: can i setup the cutoff voltage of the BMS to anything i want with a smart bms and the app? I want to try and use my battery cells down to 2.8 before they shut off discharge flow. I watch my parameters as i ride my ebikes so I would like to see if i get more range and same life span with a lower shut off voltage.
Hi. Very educational video. Thanks. Im trying to put together a battery
pack for my motorcycle with each cell 2.1 amps. 5 rows in parallel and
three cells in series to give 12.6 V fully charged at 10.5A. As Im a
newbie, I do not know which BMS I should use and how to connect. your
assistance if possible will be highly appreciated.
Hi Lee thanks. Its a great well explained video. Can you perhaps confirm whether one can use a 7S Li Ion Battery BMS 18650 module also on a 7S pack of 26650 cells?
Great video. Question - will that BMS also balance charge?
Super informative vid bro 🙌👌🤙
Great video mate, really interesting (although my wife had to translate the electronics parts) :) , battery work really good. And loved the bloopers :)
Hahaha! Brilliant. Is the wife an electronics eng then?
Yeah she’s been building printer circuit boards as a job for 20 odd years
Printed
Thanks, Good video very informative!! ....I’m guessing you have a G7x camera , I had one and that auto focus drove me nuts, if you haven’t replaced it already you can actually program in the part you are trying to focus on as a face to make it focus quicker or just use an iPhone
Hey Lee
If I’m setting my controller to max 18a will a 20a bms be sufficient of would you want a bit more margin between them or does it not matter as the BMS is only concerned with the charging aspect of the pack? Or does the load drawn from a cell pack pass through the bms meaning the bms needs to rated equal or above the max current draw from the cells. I hope my question makes sense.
Thanks
Great Vid Lee. Feel like im in esk8 school
Hey love the video! (And the bloopers 👌) I have a scenario question for you.
What if one wanted to swap out the BMS after the pack has been built and used?
*Scenario*
The buddy you're making that battery pack decides to switch out the BMS for a differen't one once receiving it. What precautions would one have to take?
Great question dude. The short answer is that is totally fine to do.
The longer answer is firstly, as always make sure you insulate any battery contacts as you go but it would be a case of just desoldering the old one and replacing it with the new one. Just observe all the usual safety precautions and you will be golden
Hey, great video. I am building a portable computer monitor and am struggling to get a system with both BMS and state of charge, so my users can see their battery level on led’s or something. Do your skate boards have a battery level indicator? Any advice for how to wire it up?
Great work lad perfect battery build but you extended the balance wires off camera this is a trick for new players may not be aware of. Only thing I would have done different would be add a inline fuse to charging port. But not required. 5 star build mate.
Yup! I fuse all my charge ports! I put the fuse on the board end of the loom not the battery. Ta bud, hope this video is useful to people venturing into battery building
what are the considerations taking into account when we trying to pick the right bms for our battery?
What S count your battery is, whether you are going to run bypass or not and what your charge current will be
I’m super new to making battery packs and anything related to bms I quite enjoyed this video and I wanted to ask a few questions that are related. First question what was the total output in voltage and amperage of the pack you made in the video?
Second question which may be dumb sounding but again new, can I make these have a voltage of 120-180+ volts?
Third question what is the max amperage if possible to run in parallel that these packs can handle?
Fourth question do you have more videos related to the bms, making batteries such as these and what I just asked about so I can watch them? I do like asking these questions to gain information but I’m more of a visual and hands on learning so it sinks in more that way for me
This video is most helpful from all the other videos I watched. I'm trying to build my first battery pack with 18650 cells 13s 3p with a lifepo4 bms (charge only). It's a 16s bms, and I believe it puts out a slightly less voltage. And I have a 2a charger for it. Would that still work?
Hey there. Great video, I am attempting to build a 7s charger and got a load of different bms models. The one I am currently testing has no bypass so what I did is split the P- line in 2 and add a switch to change between the Charger- and the Load-. This is essencially the same as the bypass configuration right? Also, if all I have is a voltage dc supply, to what voltage should I set to charge a pack of 7s lipos? 29.4V would be their 100% voltage, but can this present any danger? Should I set to a lower value?
Aw thanks dude I couldn't find anywhere how to install this game!! I just cleared Volcanic!
Can you do a video or quick topic on fuses and why one would use it and why we shouldn't use it?
Love your video,
Can you please tell me do I have to use separate or common port bms for ebike battery (72v 20s 3p, 80A continuous)
Thx
Very thanks for your nice video
No problems!
Love the video.
I have a few dead cells in my battery pack.
Is it possible to replace the dead ones. Without causing others issues with the hole pack.
Hi Lee, when the battery pack is not on a load (not connecting to any appliance or device) or even charging, will the BMS be still working automatically to balance the cells ? the cells will discharge themselves over time, not sure if the BMS still detect the pack and start balancing according to the cell parameter. Thanks !
Hi Lee, where do you recommend placing the temperature sensors. Does the phone app allow for alarming a high temperature?
Thanks,
Ed
I'm very tight on space with the build I'm planning.
Is there a even more compact bms than the daly? I plan on using it for charge only too.
Cheers for the video Lee.
Can you provide a size and link for the blue battery heatshrink please.
Where do you get the huge battery heat shrink wrap from and what size would be needed for a 12s 7p mountain board pack
I am building a 4S pack for use in my Tesla, the pack will sit in parallel with the stock battery, but will a BMS be able to let the charge current from the DC-DC converter through or do I have to solve this another way?
Thanks man. Are you able to answer some questions about my battery pack? I am trying to fix a couple of packs that have drawn too much current through their BMS systems.
Thanks for the video ;)
You are welcome bro!
I'm curious how much power the bluetooth module constantly draws.
Like a BMS always pulls a tiny bit of current, right? That's why you have to recharge unused battery packs after several months, right?
So how fast does the bluetooth drain the batteries?
What do you use for a charger. I'm building a 10s100p golf cart battery. Also do you just charge it through the pack pos?
Excellent videos would you charge to build a replacement pack for the Ninebot E+ and to ship to the Caribbean?
Great Video! You mentioned that locations of temperature sensors is important, but didnt show them. Where are those places on the battery?
Only that they need to be spread apart and need to be in close contact with the cells
Great vidro bro.can i use 14s bms to 13s battery pack and how ?
I have not built a battery but I starting to get all the equipment and supplies. What I and wondering is if I can get a bms that can do 14s and the in the future I can upgrade it to a higher 16s or hight 8f 8 want to upgrade my motor?
Hey Lee, building a 10s 36v 15ah pack seen plenty of videos of how to wire the bms but what do you use to power them to charge? I have a Li-ion battery charger that outputs 42v 1.5ah would that do it?
Hi. I have a bms from the same manufacturer and I've connected everything like their datasheet and the charge/discharge (-) wire is connected to the C- port. My doubt is not how I should split it? Can the C- feed the my esc and split into a charging port or should I use your setup (B- to the BMS and then to the esc and C- just exclusively as a charging port)?
I have a 48v 26ah pack and it had imbalace section. I got it charging then the green light come on but with I unplug the charger it falls to 38V. I plug the charger back in it shoots to 54 and stays green. I tore the battery pack open and unplugged the bms and jumper the charger straight to the battery bypassing the bms and still same result.
does the 18650 have a fuse in it? it floats 54v but no current. thanks!
What's your take on the cheap bms' on ebay? I got one for my 48v 13s battery build but it dont seem to be well balanced according to a few of the cells. It has a separate port for charge and discharge but would only charge to 4.10 per cell until I hooked the two together and now it'll fully charge but was testing each cell voltage and some are .10 to .15 higher than others
Some or all BMS boards are listed as 3s, 4s etc. Do i need to get one that matches my series? Can i use a 4s for a 3s setup? If so, which balance wire do i omit?
Which brands are good, where to buy reputable brands, what to look for in a bad/good bms.
If i want to be able to use the battery and charge it at the same time, is that possible? Do i need a specific bms for that?
Hi
please what is the difference between P- and B- in BMS and does lithium battery packs need special chargers or any smart charger can work with them ? Thanks
Hey thanks for this video, just what I was looking for. I am a newbie at battery building, but have electrical education background if I am right this is a 12S5P pack you have here right?
Do you maybe know what kind of BMS is built into generic factory built Chinese battery packs I have a 13S4P (Ownboard Zeus) pack and had a power cutout mid acceleration which catapulted me of the board...and was wondering if the BMS was the quality mf....as it definitely wasn't the road or me...
I am asking because I want to build another cruiser board with a 13S3P pack and want to choose a BMS that is a good choice between size/reliability.
Can you connect in parallel the BMS to get more current?
I'm a emtn biker using a hoverboard battery as a range extender on my Focus Jam2 ebike. I'm also looking into building some packs, learning as much as I can before I try that and have a quick BMS question. If you use the BMS in bypass mode, what keeps the bike from running down the cells too far? Must be the ebike controller preventing that because my hoverboard batteries are in bypass mode. In that case is their any advantage to running the discharge thru the BMS? If sized right won't it prevent an ebike from pulling more current from the cells than is safe preventing overheating? Again I'm guessing the ebike controller does that too. In my case I'm making an ultra light 10s1p from tesla 15A 21700's. Obviously I don't want to pull too much current from these and ECO mode will help prevent that but I'm wondering if selecting a 15A BMS and using it discharge mode. thanks, love your videos. I've learned a lot.
Awesome stuff bro! Yes for a bike you want to run in bypass for sure. The reason why we don't run in bypass on an esk8 is there are no mechanical brakes. If that BMS cuts the power you lose all braking. For an elite you don't need to worry about that so I would run discharge. Good luck and you are welcome bro, glad I could help!
Can you use any bms with the same cell count if it the same type of system? Also if it is the same type of system and cell count can you just use the existing wiring and cut and join the wires using your new bms harness?
Hi Lee. Hope you might be able to help me ... i have a copy Xiomi 365 scooter . I am sure the massive bms board is fooked. Do bms boards connect to its controller via bluetooth do you think ? I can the scooter to run for a few seconds then get the error message of no communication to battery . Some beeps and flashes counting out the error code. Im glad ive found someone in UK ,you, that might be able to supply some parts and advice for my future projects. hope to hear from you Don Codman
Great video! I have built a few packs myself so far and already know most of the basics, but stayed and watched the whole video for any new tips and tricks you might show me along the way :) Thank you!
I do have one question though, which is why I ended up here in the first place... When shopping around and looking at the specs of a BMS, they always have a 'Max Amperage' rating. However, unlike some other types of devices, nowhere in the BMS specs does it list any sort of "Peak" or "Surge" power rating. Why is that? Is that maybe because the BMS acts more like a switch, and the moment you exceed it's Max Amperage rating, it just shuts off? There is no rating for Peak or Surge power, because that's not how they work?
Correct bro. The BMS will indeed shut off if you exceed the max rating. The rating should be considered the max you can pull, I just dont discharge through the BMS so never had any issues!
@@LeeWright Perfect, thanks so much man!!
Can u please help me your video was absolutely amazing and I now understand my BMS a lot better.
But can I asks u what is the black wire that is sort of a loop it’s the only way I can put it. It’s comes from the BMS and god back to the BMS but loops on it self. Can u help me in what this duz please
I’m building a 6s 22.2v 30ah lipo battery for my board would I have to buy a 22.2v or could I buy a 25v bms and also it’s a 30ah so would I have to buy a 30ah bms?! Please help!!
Very helpful. Thanks Lee!
What about this "fish paper"...can't find it.. can I have a link to some on Amazon or somewhere? Thanks mate!
I have it for sale in my shop bro www.electricskateboarding.co.uk
does all BMS support series connection? example 12v + 12v to 24v. will it burn out when charging in 24v ?
how did you wire both a Bluetooth unit and the vx1 to one com port on the vesc?
I have a mercdes smart ebike with a 48V 8.4AH battery.Cells are still good but BMS is shot.BionX which made the battery is defunct. Any suggestions for a Replacement!
hi grate vid you inspire me would this work as a field charger for lipos
but with out the bms and a ballance lead
I've got a summerboard V2 Battery. It's refusing to charge, but I have about 80% left on the battery and it will still run my board (got a free replacement - Aaron mentioned about a problem resistor on the earlier V2 batteries?).
I'm getting the red blinker of death on the battery, but I was wondering. Would it be a BMS problem or I have a bad cell? Annoying, the bloody thing is actually well made and I've only managed to get it out of the casing and do some simple voltage checks.. Would sticking a different BMS work? or would it be easier to just rebuild and try and fit it into the current battery enclosure?
Hi Lee, I just bought a BMS from LLT Power (same mfgr as the one you demonstrated). I can't find a wiring diagram or manual for this unit. It's a 14S 100A Discharge and Charge unit with BlueTooth, and a couple temperature sensors. There is a B- terminal , and a C- terminal (no P- terminal). How do I connect this to my charger and to my load? It also has a two conductor JST connector with black and red wires next to the balance voltage connector, but I have no idea what this is for. The silk-screen on the board by this connector says "SW". (switch?) Have you seen one of these before? Can you point me to a manual or diagram, or give instructions on connecting this to my battery, charger, and ESC? Thanks!
Hi, if I have a controller that have maximum current 48v 18 amp and i put a battery that has 48v 40 amp i will burn the controller? Thanks
Question. I have a bunch of 30 volt lithium ion batteries which came from hybrid cars and I need to come up with a BMS that will protect them from over and under charge. I am new to this so any ideas how to do this? Thanks.
Is it worth buying the lacroix smart bms for an 18s8p set up??
Do need themistor BMS for 20s?
And how much capacity BMS need for 1500W 72v bldc controller ?
Hi bro im getting to the point of needing to setup my batteries in a bigger beast box size say. I have 2x 245kv 6364 turnigy sk3 motors say they need 10s 70amps each. Erpm needs to be set at 60000 because its at limit an at 10s is over that 63455erpm what's the best for me?.An can you put a 12s on an limit erpm to 60000 so they never reach braking point I have 2 so I need 140amps controller as well.Im looking for the best battery thinking 2x 5s 10000mah lipo or 10s3p lithium ion so I would love to no as I'm setting my first electric mountain board up.Thanks love the show thanks lee your a God send to me your times of topics are perfect to my construction.Still waiting on parts anyway so I have been doing it slowly jump up an down when bitz come.
Hey Lee, how do you prevent your battery from over discharging if you bypass the BMS?
We used motor controllers that are able to monitor and cut off at a preselected pack voltage mate
Thanks!!!!!!
Fantastic Lee, really nice details. Why do you cut the heat shrink at the end leaving the BMS a bit exposed? Also, how do you calculate how many nickel strips you put on? Also, when you connect two groups laterally, are you bending the nickel strips? Thanks
The BMS I freed as the heat shrink was putting too much pressure on it. It won’t move because of the wiring. Batteries are a whole other topic and I’ll go over that in detail very soon. But yes, bent nickel between the groups across the pack and braid along the length of the pack to keep some flex
@@LeeWright That would be very useful to know! I use to build my batteries like two identical halves and I connect them with a cable. Your approach is new and interesting for me, maybe only disadvantage is red cable must have to travel from the other far side. Wondering about what this "braid" could be, never heard about it...
@@LeeWright oh I see. Will you take any measure to prevent water ingress on it?
@@negaopiroca2766 no mate, theres only so much you can do with it. I Leave that to the customer
@@biltre21 i agree with you regarding the positive wire, remedy is to put the BMS at the opposite end and rotate