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.
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!
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!
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 👍
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!!
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
@@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
Hello brother, I have a 3s 40A bms setup for my batteries, yesterday they worked fine but today as soon as i connect a load the Output voltage of the BMS drops to 6V from 11V making the load inoperable. This board is even new already threw one 3S 25A board for facing similar issue. Pls resolve or guide me if u know. when load gets disconnected BMS shows Op again to 11V...each battery has 3.78, 3.79 and 3.80V, its molicel
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?
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.
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.
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 👍
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
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.
Hey dude great video! Can I ask you something, I've built a 13s pack for a scooter and the 2 BMS I try on discharge mode for some reason are 11v less than the battery?? So the battery is 53v and the BMS discharge is 42v?? That's same with 2 BMS now. You have any idea why that is?? It's wired 100% right. Hope you reply. Thanks 👍
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?
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...
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?
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.
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
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, 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 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
So when you plug that battery into the charger are you charging through the dean connector. Because the lithium polymer batteries I have the charger connects to the main battery positive and negative and then it's only a 4S battery so the charger also has to be plugged into the cell balance lead. So that way it can keep an eye on the cells while it charges through the main lead. And you have 60 cells but you only have 12 banks monitor so all the cells that are in parallel technically you don't know what each individual sell voltages is for your setup. I'm new and just trying to figure all this out.
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?
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!
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?
When looking to select a BMS, how is the current rating selected? Do you select on that can handle the 1C rating of the battery pack or maximum C rating? (ex. 5C)
Good question. It depends on several things. If you are using a BMS with the discharge path through the BMS then you have to consider how much the load will pull and if the battery can supply that. If you know the load will pull 200A and you have a 300A continuous battery then maybe selecting a 250A discharge BMS would be prudent
I have just joined your channel not because I skateboard but I am interested in the battery side of the system, looking at the video I see you make battery packs so do you make packs for customers I have a disability cart with two 20 amp batteries in series giving 24 volts and want to update to Lipo cells so how many cells would that be, please?
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
@@africans1968 oh you are asking about voltage... I thought Amps. So you need a 50.4V charger (12S) - I have them on our site. I thought you were talking about charge current
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.
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.
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?
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?
ok, if were bypassing discharge with bms, what is prety wise, because discharge is manageable with controller, what amperage should be used of bms in, lets say 16p7s pack of Samsung 50E 21700 batteries?
If you are only using the BMS to charge then you can charge up to 18A dude, whatever you find the best really! You can easily charge a big pack like that at say 15A or 4A (it will just take longer)
Does it matter what kind of bms is used when using regen braking? I hawe bms with p - port, I want to replace it with common port smart bms(that is what I was able to find in this size and already ordered it, the question about regen came after fact :P) so the question is, what does control the regen so the battery does not explode, is it motor controller or bms? And does the kind and brand of bms matter when considering the use of regen braking?
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!
@@LeeWright okay cool. So I was considering making an electric go cart with the VESC 100/250 and a massive motenergy motor that’s rated for 48-72V. I wanted to know the largest battery I could use for this, but some ppl said to base off the nominal voltage of 3.6 while some said to go by 4.2v. With the motor being the only limiting factor, should I go with 16s or would I be okay running with 20s?
@@LeeWright okay thank you. It seems like the main result of more voltage is over heating. Idk if that would be a problem though since the motor has loads of torque and is massive. I’ve also seen a video of a go cart with the same motor running 20s, and it didn’t seem like he had any problems.
@@koenwilliams8819 as with everything, the operating parameters are safe limits but you can do what you want. My advise is to stay within the ratings, but you dont have to listen to me!
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, 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?
Hey lee everybody says that all the cells need to be the same voltage before wiring and all that stuff and i wanna know what to do if for example one cell is not do you just through it away or maybe charge it up or something. This hasnt happened to me yet but i wanna be preapared if it does.
Yeah you would either need to discharge the cell that's high or charge the ones that are low. It's only super crucial for parallel cells, series groups not so crucial but if they are 100mv or more out your charger will struggle to balance them, the smart BMS can do it but it takes a while
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?
When choosing a BMS, how do I figure how many amps I will need in a BMS? I am going to try a 20s 15p. 18650's are rated at 30 amps each. Motor is 10kw, controller draws 700amps peak and 280 nominal. Was looking at getting a smart bms but want to make sure I'm getting what I need for the application. Thanks
Depends on if you want to use the BMS for discharge. I personally don’t so it’s irrelevant. I discharge straight from the battery. If you want to use a discharge BMS, the figure out what you want your maximum battery current you want to the motor controller and spec a BMS for that
So can you use any bms without discharge? I purchased an ant 400amp bms that has the bluetooth feature. Just trying to figure out if it will be fine for this setup. Thanks for the reply by the way. New at all this stuff and still learning.
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!
I just bought a lifepo4 golf cart battery and a 10amp lithium charger from china Alibaba with a custom metal box to fit my existing frame for a simple drop in installation. It's a 36 volt 100ah with 1 Bluetooth BMS system. They told me not to series 3 12 volt batteries together as it's not stable? My only concern is explosion. Any thoughts on 3 12 volts in series with 3 BMS vrs1 36 volt and a single BMS?
Lee i have a trampa power switch in place of an xt60 connection. Just to verify if i cut the red and black wire going to the power switch and solder an xt60 connection is that correct? I ordered and am using the exact smart BMS in this video.
@@LeeWright in the diagram in your video it shows an xt60 and xt90 connection. On my trampa board i have the xt90 connect and a power button but no xt60 connection. I assume i would have to cut the red and black wires to my power switch and solder an xt60 connection in line with the wires
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
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.
@@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.
the BMS for my 14s ebike batterie has cables connected to two C minus and also two B minus ports - should I use only one C minus and one B minus port like you showed - or should i combine the two C minus cables to one cable - the same for the two B minus cables ? Is there an advantage using the two C minus and B minus ports combined ?
@@LeeWright My first charger for my 14s ebike batterie is rated 58,8 Volt / 6 A the second one is rated with 58,8 Volt 8 A. Do you think I have to double up the C - and B - cables ? I will use your connexion layout from this video.
Hello brother, I have a 3s 40A bms setup for my batteries, yesterday they worked fine but today as soon as i connect a load the Output voltage of the BMS drops to 6V from 11V making the load inoperable. This board is even new already threw one 3S 25A board for facing similar issue. Pls resolve or guide me if u know. when load gets disconnected BMS shows Op again to 11V...each battery has 3.78, 3.79 and 3.80V
peach it has already had all that in the past yeah, the owner left the board switched on for months by mistake though! Drained the pack right down so I built him a new pack and repaired a motor whilst I was there
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 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.
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.
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.
Man I absolutely love the music in the background! Keep up the awesome videos Lee!
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@
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?
Is it safe to discharge straight from the battery? You could over discharge the battery right?
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!
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!
is it possible to connect 4 bms's in series for a high voltage pack ?
Can you connect in parallel the BMS to get more current?
Thanks! Assembled my first battery with this guide, works perfectly!
Well done brother! I'm really happy that this helped!
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!!
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
Hello brother, I have a 3s 40A bms setup for my batteries, yesterday they worked fine but today as soon as i connect a load the Output voltage of the BMS drops to 6V from 11V making the load inoperable. This board is even new already threw one 3S 25A board for facing similar issue. Pls resolve or guide me if u know.
when load gets disconnected BMS shows Op again to 11V...each battery has 3.78, 3.79 and 3.80V, its molicel
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?
Best BMS video on UA-cam, nice 👍
Thank you!
Sir can we use 4s bms with 3s battery pack...?
Good advice with the smart BMS and the fish, kepton tape! Keep up the great work. Thx a lot
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.
Will bypassing the BMS stop the remote features? Such as battery range left, and speedometer?
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!
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?
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 👍
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!
Thanks mate, I just got exactly what I need for the charging stuff.
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.
Hey dude great video! Can I ask you something, I've built a 13s pack for a scooter and the 2 BMS I try on discharge mode for some reason are 11v less than the battery?? So the battery is 53v and the BMS discharge is 42v?? That's same with 2 BMS now. You have any idea why that is?? It's wired 100% right. Hope you reply. Thanks 👍
Hmmmmmmmm, I don’t know. I’ve heard about this before but never experienced it myself. I have no idea I’m sorry mate
@@LeeWright No worries thanks for getting back to me 👍
What did you use to connect the packs together, making it flexible. It didn't look like a nickel strip
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?
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
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?
Great vidro bro.can i use 14s bms to 13s battery pack and how ?
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, where do you recommend placing the temperature sensors. Does the phone app allow for alarming a high temperature?
Thanks,
Ed
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!
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
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, 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 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
So when you plug that battery into the charger are you charging through the dean connector. Because the lithium polymer batteries I have the charger connects to the main battery positive and negative and then it's only a 4S battery so the charger also has to be plugged into the cell balance lead. So that way it can keep an eye on the cells while it charges through the main lead. And you have 60 cells but you only have 12 banks monitor so all the cells that are in parallel technically you don't know what each individual sell voltages is for your setup. I'm new and just trying to figure all this out.
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?
Excellent videos would you charge to build a replacement pack for the Ninebot E+ and to ship to the Caribbean?
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!
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?
Can I connect the battery directly to the hover board, bypassing the BMS?
When looking to select a BMS, how is the current rating selected? Do you select on that can handle the 1C rating of the battery pack or maximum C rating? (ex. 5C)
Good question. It depends on several things. If you are using a BMS with the discharge path through the BMS then you have to consider how much the load will pull and if the battery can supply that. If you know the load will pull 200A and you have a 300A continuous battery then maybe selecting a 250A discharge BMS would be prudent
I have just joined your channel not because I skateboard but I am interested in the battery side of the system, looking at the video I see you make battery packs so do you make packs for customers I have a disability cart with two 20 amp batteries in series giving 24 volts and want to update to Lipo cells so how many cells would that be, please?
Welcome! 7S would be 25.2... lithium operates at different voltages to lead acid and you would need to look Into a DC-DC converter
Hi Lee, can you do the bypass with common port BMS?
Thanks
Good question. Yes - just use the P- as your charge port negative and charge port positive to battery positive as usual.
@@LeeWright great!
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
Hi Lee, what power voltage charger do I need for a 12s4p?
Thanks
Depends on the cells dude, look up the data sheet to see the nominal charge current then multiply than by 4 to get your max charge rate
@@LeeWright the nominal per cell is 3,65v if I multiply by 4 it gives me 14,60v 😭
@@africans1968 oh you are asking about voltage... I thought Amps. So you need a 50.4V charger (12S) - I have them on our site. I thought you were talking about charge current
@@LeeWright thanks for your help, I will have a look to your site.
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.
What a GREAT Video!! Exactly what I was looking for. Thank you so much!
Where do you get the huge battery heat shrink wrap from and what size would be needed for a 12s 7p mountain board pack
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.
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?
so blutooth is always on?? will that not drain the battery over long time storrage?
Over a long time yes, its low energy, you would be alright for months at a time
Would that not be beneficial for the batteries life over long term?
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
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?
does all BMS support series connection? example 12v + 12v to 24v. will it burn out when charging in 24v ?
Is it worth buying the lacroix smart bms for an 18s8p set up??
Have a E bike is it safe to bypass the BMS for discharge?
Cheers for the video Lee.
Can you provide a size and link for the blue battery heatshrink please.
Great video brother. Appreciate the effort and it was super informational. Gonna use it for my build.
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?
great info ! , can you recommend a reliable anti spark mine has failed twice on my raptor : /
I think the saying is there are no reliable anti spark switches. Best to use a loop key if you can 👍
I thought about it at this point lol , is that not bad for the esc's
@@weaksaucep4539 na, totaly fine bro
What is the maximum current of the BMS you are using now.
20A, but it is bypassed for discharge so doesnt matter
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
ok, if were bypassing discharge with bms, what is prety wise, because discharge is manageable with controller, what amperage should be used of bms in, lets say 16p7s pack of Samsung 50E 21700 batteries?
If you are only using the BMS to charge then you can charge up to 18A dude, whatever you find the best really! You can easily charge a big pack like that at say 15A or 4A (it will just take longer)
hello, my friend,i wonder what facilities you need to do this test?
Is it ok to connect the first black cable to B- directly, instead of the negative of the battery? It's a shortcut
Hello there! Where can I buy the bms12S 30A Bluetooth?
Does it matter what kind of bms is used when using regen braking? I hawe bms with p - port, I want to replace it with common port smart bms(that is what I was able to find in this size and already ordered it, the question about regen came after fact :P) so the question is, what does control the regen so the battery does not explode, is it motor controller or bms? And does the kind and brand of bms matter when considering the use of regen braking?
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!
Hey lee. What’s the best way to ask you an esk8 question?
Like you just did bro 😄
@@LeeWright okay cool. So I was considering making an electric go cart with the VESC 100/250 and a massive motenergy motor that’s rated for 48-72V. I wanted to know the largest battery I could use for this, but some ppl said to base off the nominal voltage of 3.6 while some said to go by 4.2v. With the motor being the only limiting factor, should I go with 16s or would I be okay running with 20s?
@@koenwilliams8819 you should base your operating limits of of fully charged, so 20S would be too high of a voltage. 16S would work really well dude
@@LeeWright okay thank you. It seems like the main result of more voltage is over heating. Idk if that would be a problem though since the motor has loads of torque and is massive. I’ve also seen a video of a go cart with the same motor running 20s, and it didn’t seem like he had any problems.
@@koenwilliams8819 as with everything, the operating parameters are safe limits but you can do what you want. My advise is to stay within the ratings, but you dont have to listen to me!
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
Hello,. I'm planning to build my own battery, 36v15ah,.what type of BMS do I use.. Thank you.
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 video. Question - will that BMS also balance charge?
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?
Hey lee everybody says that all the cells need to be the same voltage before wiring and all that stuff and i wanna know what to do if for example one cell is not do you just through it away or maybe charge it up or something.
This hasnt happened to me yet but i wanna be preapared if it does.
Yeah you would either need to discharge the cell that's high or charge the ones that are low. It's only super crucial for parallel cells, series groups not so crucial but if they are 100mv or more out your charger will struggle to balance them, the smart BMS can do it but it takes a while
@@LeeWright thanks
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?
When choosing a BMS, how do I figure how many amps I will need in a BMS? I am going to try a 20s 15p. 18650's are rated at 30 amps each. Motor is 10kw, controller draws 700amps peak and 280 nominal. Was looking at getting a smart bms but want to make sure I'm getting what I need for the application. Thanks
Depends on if you want to use the BMS for discharge. I personally don’t so it’s irrelevant. I discharge straight from the battery. If you want to use a discharge BMS, the figure out what you want your maximum battery current you want to the motor controller and spec a BMS for that
So can you use any bms without discharge? I purchased an ant 400amp bms that has the bluetooth feature. Just trying to figure out if it will be fine for this setup. Thanks for the reply by the way. New at all this stuff and still learning.
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!
I just bought a lifepo4 golf cart battery and a 10amp lithium charger
from china Alibaba with a custom metal box to fit my existing frame for a
simple drop in installation. It's a 36 volt 100ah with 1 Bluetooth BMS
system. They told me not to series 3 12 volt batteries together as it's
not stable? My only concern is explosion. Any thoughts on 3 12 volts in
series with 3 BMS vrs1 36 volt and a single BMS?
Lee i have a trampa power switch in place of an xt60 connection. Just to verify if i cut the red and black wire going to the power switch and solder an xt60 connection is that correct? I ordered and am using the exact smart BMS in this video.
I'm not sure what you mean bud? The power switch is on the VESC yeah?
@@LeeWright yes it comes off the vesc instead of the xt60 connection
@@LeeWright i emailed you a picture im sure you have a million emails however
@@LeeWright in the diagram in your video it shows an xt60 and xt90 connection. On my trampa board i have the xt90 connect and a power button but no xt60 connection. I assume i would have to cut the red and black wires to my power switch and solder an xt60 connection in line with the wires
Thanks in advance for any help i will try to donate via patreon
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
how did you wire both a Bluetooth unit and the vx1 to one com port on the vesc?
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.
I'm upgrading my solar flood light - powered by X2 18650 batteries should I put a bms in or not??
I'm new to all this .... Absolute beginner
the BMS for my 14s ebike batterie has cables connected to two C minus and also two B minus ports - should I use only one C minus and one B minus port like you showed - or should i combine the two C minus cables to one cable - the same for the two B minus cables ? Is there an advantage using the two C minus and B minus ports combined ?
I guess the cables are doubled up for larger charge currents, what is your charger rated for? That's the only reason I could see to do that
@@LeeWright My first charger for my 14s ebike batterie is rated 58,8 Volt / 6 A the second one is rated with 58,8 Volt 8 A. Do you think I have to double up the C - and B - cables ? I will use your connexion layout from this video.
Can you do a video or quick topic on fuses and why one would use it and why we shouldn't use it?
Hello brother, I have a 3s 40A bms setup for my batteries, yesterday they worked fine but today as soon as i connect a load the Output voltage of the BMS drops to 6V from 11V making the load inoperable. This board is even new already threw one 3S 25A board for facing similar issue. Pls resolve or guide me if u know.
when load gets disconnected BMS shows Op again to 11V...each battery has 3.78, 3.79 and 3.80V
12s5p in an evolve? What evolve has space for that much battery? Or is it a modified enclosure?
Evolve Gen 2, they are huge!
@@LeeWright amazing, I'm assuming vesc and motor upgrades too. Should be a beast.
peach it has already had all that in the past yeah, the owner left the board switched on for months by mistake though! Drained the pack right down so I built him a new pack and repaired a motor whilst I was there
What if you have two batteries 6p 13s . And you wire them in parallel. Can you use one bms
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.
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 👍
Hello! Im missing the calculations for what BMS to take, Ampere etc.
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.
If you discharge is bypass is there still a low-voltage protection meaning you can't run the batteries to low
Aw thanks dude I couldn't find anywhere how to install this game!! I just cleared Volcanic!