How to wire a BMS
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- čas přidán 4. 02. 2016
- All common BMS's are wired in the same way. I'll show how and where to connect the B-, C- and P- to the battery, charger, and power output. See my other video for sensor wiring. I will be wiring a BatteryBlocs battery, but the principals are the same.
If you enjoyed this video considering donating to Macklin's school fund. www.crowdrise.com/macklins-
The most clear explanation of how to wire the BMS and I finally (after 14 videos) understand what C- P- & B- mean. I had bad luck clicking on BMS videos--wish I had clicked on this one first. I just subscribed because you nailed it for me. Thanks,
I don’t care how old this video is.. you definitely gained my sub. Cause you actually explain what you’re doing and what’s going on.. thank you for that!!!!
Thanks for the video Shawn, I had a BMS and thought the "P" connection was positive to charger - and I was baffled by the charger shutting down. Very helpful and BMS is now working as it should.
That is logical! Glad you solved the problem.
:-)
@@dannypittillioen2558 Then I think- not positive- that your BMS was designed to be charged and ran through the same two wires. So the charger would be connnected to the power wires.
Thank you ! I finally learned to wire the BMS to 48 volt battery with this video....I even used my little vice to hold the XT 60 to solder
fucking brilliant.. great Tut.. No stupid fucking music.. No Bad language... straight down to business.. Top Man...
We need more people to eround the globe like this one
Thanks Milo, I am glad the video was helpful.
Very informative and helpful! Thank you for posting!
That was a long but good video with some good soldering tips. Just to be clear that the load is the controller not the motor. The thing is can I eliminate the load/controller for this, as I really don't want to wreck my cheap BMS by constantly running voltage through it. Thanks Shawn. Have resolved my running issues with my Ebike cutting off. This is for all of you who have a faulty battery. I started with a recycled 48v 13 x 4 series battery 12 Panasonic 3400mah 1 sanyo red cell. Once I replaced the 1 red Sanyo cell with 4 more Panasonic that resolved the voltage drop problem. I added another 2 lines of Sanyo cells i.e. Now making it 13x 6 cells. Problem solved except for the fact that my display doesn't shut off connection with motor and doesn't show speed mileage etc. We venture on into diagnostics to make this world a more trouble free place. Thanks for all your help. My Lyen controller and analyser will arrive in the post soon.
Thanks for the very clear step by step guidance.😊
Awesome video and great explanations for the connections, I learned a lot. My only suggestion would be to trim your leads and instead of mounting the wires from the top, bend your wires at a 90 degree angle and mount from the underside. You would have a better solder joint and less chance of shorting plus it looks a whole lot nicer. Again, Thank You very much for the awesome video.
in your diagram above, where would the solar panels go. Interested in replacing my Pb battery, PV setup for my trailer with lipo. Woohoo another vid. Thanks Shawn
thank you for this vid, now its al clear to me. :)
You are welcome, and you must be pretty sharp! Good luck on your project. You might also enjoy my video on building a safe battery without a bms..
Tx so much from the bottom of my heart you made my day.
Thank you i wired my at the same time you did yours good dude and thanks again
WOW, AFTER I SEEN THIS VIDEO IT GAVE ME SO MUCH CONFIDENCE...I THINK I HEARD THE ANGELICAL VOICES.......AAAAAAAAAAAAAAAAAAHHHHHHHHHHHHHHHHHHH,
MERCI : )
Join the boat of grateful disciples :D
Great Video! If the electric vehicle or scooter or bike has regenerative braking (on the M365 scooter it’s called kinetic energy recovery system) would this same type of BMS or wiring configuration be utilized? I’m researching how to wire my Genasun Boost Charger which allows me to charge my lithium scooter battery with solar cells which connect the solar cells to the 36Volt battery. I know the scooter already has a BMS, I just wasn’t sure if it was required to add an additional BMS because I’m charging with solar cells while I ride the scooter, verses my original BMS which disabled the ability for the scooter to be ridden while the scooter is charging. If you have any thoughts on this, I’m very interested to hear them. Thanks in advance.
If your BMS will not let the scooter run while being charged, you will have to use a different charging route. A second BMS is an option. But I would just open the battery up and test solutions empirically, - just try out different things and see if you can get it to work.
Thank you! Question, could you run two separate positive wires from your battery to the “charger” and the “load” instead of running them through the same wire?
Thank you for the time in explaining these. Here's my question for my build: your working on a small battery bank. What if my bank will be on my bus (Motorhome) with a large scale bank? Your working with tiny little wires, I would imagine my wires and equipment will be lot bigger.. I'm going to be running a solar array of +/- 1200w and +/- 5000w Victron Inverter/charger with a battery bank of maybe 600-800AH of lifepo4 batteries?
Hi Steve,
You could use a voltage activated relay that will turn on a load- like a light bulb- to bleed each parallel group if it gets too high....
Great video! This vid should have more views :D
wish I could give ur vid more thumbs up :D
Wow, thanks! Hope it helps. Let me know if you have specific questions.
Haha glad to see your vid is getting more attention!!! Truly the most helpful vid I have see for beginners on BMSs!
Yes, I'm surprised. My "How to build a better battery without a BMS is doing well too! Thanks.
If i have a 48v battery with a bms what voltage do i need to charge my battery pack with?
Thank you for an excellent explanation of BMS wiring.
I have been trying to design a 4S1P LiFePO4 battery for my motorcycle but I have encountered a problem which I cannot find any solution for on the web. A motorcycle battery is charged constantly as it is being used. There are separate connections on a BMS for P- and C- but on a motorcycle these are not separated. The positive charging current is fed into the wiring loom and there is only one positive wire at the battery. There is no negative wire feed from the alternator. The alternator is connected to the frame of the motorcycle, as is the negative wire from the battery (i.e. the "negative earth" system). I don't see how it would be possible to connect C- and P- to separate places.
Good comment! Gerry, I don't see why you could not connect the B- to the frame, and the P- to the battery. It is just like in a car, where the chassis serves as the ground loop. Of course, the Positive wire goes to the fuse box, right? I don't see any reason why not to wire it as you have proposed-am I missing something?
like the way u did your video charger plug goes to the charge controller ?? and the load would go to the power inverter?? new to the b m s. over charge some batterys so I am doing b m s now. thank u for the input learn a lot thank u so much.
Hi Dave,
The Battery Charge plug goes to the negative of the BMS and the positive of the battery. The load goes to the inverter for a house, or the controller for an ebike. It just goes to the load. Good luck!
When you strip the wires and after being checked for proper fit then tin the wires and finally trim for size before mounting. Your connections will be a lot stronger and neater and much easier to use heat shrink tubing.
might want to try mylar sheets or packaging plastic to go on the BMS under the electrical tape. I've found the sharp ends of the contacts like to work through the tape but not so much the others.
Yes, good idea. I like to use dollar store foam board, especially when packaging a spot welded battery.
Hi Shawn. Thanks for all your help building/maintaining batteries. What BMS would you recommend? I built a 10S 6P 36 volt 14 Ahr battery for a used bike I bought that didn't have a battery. I'm probably going to go the route you showed using hobby chargers. But, I'd like to have a BMS in case I decide otherwise. Thanks, Mike
I have had mixed luck with all the BMS's I have tried. I am using this vendor's BMS's now:
www.aliexpress.com/item/High-quality-14S-18650-lithium-battery-BMS-for-electric-bike-lithium-battery-with-20A-continuous-discharge/2030986292.html?spm=2114.13010608.0.0.EnNsE4
I suggest ordering two, in case one is a dud.
BTW the 10S 36 volt battery is a natural for a 10S hobby charger.
What a great job explaining bms! Keep on man! What bms would you recommend? What did you use in this video?
Hey Afron,
Thanks for the thumbs up! I recommend you buy your BMS's from an original manufacturer like www.BesTechPower.com.
I personally do not NOT like BMS's and wire my personal batteries to be charged with a hobby charger. Running a battery repair business half of all the problems are caused by a defective BMS. (Most of the other problems are bad connections.)
Ok thanks for the valuable info. So, I am wondering, would balance charging the pack be enough? Do I really need to worry about them discharging at different rates?
If you have a small pack- small meaning that you often run it to empty or close- you need to have a way of monitoring the voltages of the cells so that you don't discharge them too deeply. So, if small, then yes.
I use cell loggers for this. Hobby king sells them, for example. They monitor up to 8 P. So for a 36 volt 10P battery you would need two of them. When a cell voltage drops to a preset place, an alarm sounds.
Normally the BMS would shut off the battery here. But you have a choice- do I want to keep riding a little more or not?
You can also use the BMS just for charging-- and run directly from the battery bypassing the BMS. But again you would want to use cell loggers.
Ok good to know. My battery pack build is going to be 48v 20ah. I plan to make 10 in parallel, 13 in series. So I guess this would not be considered a small pack. I wouldn't think I would use the battery pack past the point the bms would shut it off.
SO you could bypass the BMS to run the battery- but you would still want to use a cell loggers to warn you if the voltage got too low.
hey bro,....I suspect I have a bad mosfet,...do I have to remove them All to test them individually? (greenhorn question,..I know) :-)
Thank you very very much
Thanks for the video Shawn. I have to replace a 80A in/out BMS/PCB on a 12v 4s60p pack with no separate charging port (charge/load through same port). Is there a specific order the wires need to be connected/soldered to the BMS? Also, I have 5x 12g black neg wires soldered together going in and 5 together out. What is that fifth wire on a 4s? Thanks
There is no specific order the wires need to be connected in. It is good practive to leave the JST-XH- the sensor wire connector disconnected from the BMS while wiring it. Then, check the voltages at the JST to be sure you have it right before connecting. There is always one more wire than the number of S. One wire goes to battery negative, the others go to the battery positives.
Thanks. I have another question...at Bestech they have a bunch of different BMSs, most have a max charge rating as a single number, 100a for example. A few have a max charge expressed as a range, like 5a-100a. Does that mean that current below 5a wont charge? Also, whats the important design/component differences between a BMS with dedicated charge wire in (3 solder points) and one with combined charge/discharge/load(2 solder points)? Thanks
Sorry, I don't know why a BMS maker would bother to put a minimum charge rating on their BMS. I also don't know the circuit reasons for a dedicated charger wire- though I would assume it is a better quality.
Hello Shawn,
Thanks for this video!
At the moment I am looking for a batterypack for my new underwater light. I am surfing the internet to gather some information.
I see also BMS circuit boards that only use 1 connector for both charging and discharging via a load.
For me that would be great because I only have to mount 1 connector.
Is there a specific reason to use 2 separate connectors??
Thanks,
John
Hi,
Using one connector from the BMS to the Load will work fine. Typically the negative wire will pass through the BMS and the positive will go straight to the battery positive.
Hi Shawn, I'm having a heck of a time finding JST XH connectors. I ordered some that I must put together, my sight makes that difficult. Any recommendations would be appreciated.
Hi Sean,
Sure- try BuddyRC
www.buddyrc.com/catalogsearch/result/?q=jst-xh
Superb video interesting but you need a bit more practice with soldering an xt60 i too forget the shrink wrap great video keep them coming
Ok, I've got a capacity checker that I will use periodically to keep an eye on my battery packs. Do I need to wire in a PCB made specifically for my 2s packs?
yes and put it in parallel with the battery plus and the bms negative out put
Hi can i check voltage from charging port
Thank you
In diagram battery red wire is connected to the charger (blue) then with load (yellow). But in practical you added battery red wire with load (yellow) then charger (blue). Is there any difference?
Where can i buy these batteri blocks?
Thanks
I have a XiaoXiang smart bms for my 16S 4P LiFePO4 battery for my Ebike. I have 17 sense wires, and I have 2 large gauge wire labels C- and 2 labeled B-, I also have 2 small black wires off to the side which I believe are temperature sense wires. There is nowhere on it labeled “P”. I’m confused. Any suggestion?
Hmm, It sounds like a regular BMS but with doubled up Battery Negative and Power Negative wires. The B- would go to the battery negative, of course. The remaining two would go to the Power Negative... No instructions : (
may I ask I have this type BMS use in 14s5p lipo 5200mah, (52v26Ah), can I use to14s 2p (52v 10.4Ah)? how to connection. uegent!!
Yes you can, it will work just fine, even better. Connect it just like it is connected to the old battery.
Hi! Much thanks for the great video... Im kinda new in electronics so i got one question that i dont understand well. I know the basics but what bothers me is the thing that i live in central Europe and we got 220 v (ac) and in America is 110 v (ac). So what happens when i try to charge a finished battery pack 48v or 52v? Guessing i need to buy some ac dc recharge kit or wtf?
Nothing, your hobby charger is specific to your country's voltage. They come in 110 and 220 volt versions and convert the AC to DC. Or, order one that is powered by 12 volts and use a car battery....
Shawn McCarty ... Ok thanks seems legit and im aware there is sh.t lot of stuff out there and many versions and variants but your idea with 12 v car battery is ok and since im not the person for just the one solution im asking is there some recharger that can charge different voltage. That i can charge car battery 12v or e bike batery 48v.
HI Shawn, I love watching all your videos, thanx for all your help. I have a problem... I tried ordering a 48v 13s 30a bms with wiring similar to your bms......but the first set of 11 wires has 1 black, 9 whites and 1 red........the next set of wires has 3 wires, black, white and red .............. the bms its the LH-HP20SA, can you please help.
Ignore the colors. Your BMS is probably marked with a - on one side of the JST-XH connection, probably the side closest to your right hand. That goes to the negative of the battery pack. The following wires go to all the positives of the parallel groups ending with the positive of the battery pack.
The colors are not relevant in your case.
Nice video, very useful.
I have a solar charge controller (charger) and an inverter (supplies load AC current). In my application, I have an inverter that can also charge the battery, using household electricity. Will your schematics still work or do I need any other modification? My concern is since the negative of the inverter is not connected to the solar charge controller directly, can it be used to charge the battery too?
So you have two ways to charge your batteries- one is the solar charge controller and the other is an AC to DC converter that runs on house power, right? The 2nd sounds just like any other power supply or battery charger, so there is no reason why it can't be connected to the BMS like any charger-----but am I missing something?
Thanks for the prompt reply. The inverter can perform the work of an AC to DC converter and also draws power from the battery to supply the load. This means I could normally connect it to load part of the BMS to convert the battery DC to AC.
My question lies in the function of charging. Since it is connected to the load section of the BMS, can it be used also for charging just like an AC to DC converter without disconnecting it as load and connecting it as charger?
No, I don't think so. The problem is in the BMS. The load side is designed to cut out at a low battery voltage and to cut out if more amps are drawn than the BMS can handle. The charge side of the BMS is designed for a much smaller current. Essentially it sounds like you want to connect the load and charge sides of the BMS together through the inverter/converter.... I have never tried that. I suppose you could try it under a small load and see what happened...!
Thanks very much
HOW MANY MILIVOLT THE BMS TAKE INTO CONSIDERATION TO DECIDE IF A CELL IS UNBALANCED
great video. I have a question however. I have read that BMS's can bottleneck the charge amount. Is this the case? can it be increased by putting them in parallel? thanks
The charger slows down the charge rate. Chargers start charging at full current, which is the max output of the charger, say 5 amps. The battery voltage slowly climbs. When the battery voltage reaches max voltage, the charger keeps backing down the charge current to keep the battery voltage from going above the max voltage-- keepng the voltage constant. These phases are called Constant Current and Constant Voltage-CCCV.
The BMS monitors the voltages of each parallel group. If one of the voltages gets above say 4.1 it starts to bleed that parallel group. However, it has a very tiny bleed current. If it cannot keep the voltage below 4.25, it shuts off the charge to the whole battery. So, the weakest cell determines how charged the entire battery gets. Battery capacity gradually diminishes.
I see no reason why BMS's can't be used in parallel while charging. A BMS does use some current while charging, reducing the charge current going into the battery. However, the end result of using two BMS's in parallel imho will be a battery that is better balanced, not charged faster..... To charge more quickly, use a higher amp charger limiting the charge rate to the C value of your battery.
hello sir.
just 1 question.
In your diagram,
1. does load means controller?
2. does charger plus means charging point socket?
please tell. i have made my lifepo4 87.6v, 42Ah. only the bms part is left. i have this type of bms with b-, c-, p- setup.
Hi,
Hey that is 5 questions! Are you trying to confuse me? ; )
1. B- connects to the negative of the battery
2. C- connects to the negative of the charger
3. P- connects to the negative of the load- in your case, a controller.
4. The charger positive goes directly to the positive of the battery.
5. The controller positive goes directly to the positive of the battery.
good luck!
What do you call the blue connector?
I have 2 3S lipo batteries 5000 mAH in parallel. can i charge that with an 3S BMS?
Sure, the BMS or hobby charger will see it as a 2P3S battery-- Two cells in parallel, 3 cells in series. I'd use a hobby charger for that one....
I'd like to know more about that cell holder.
Sure. The cell holder is made by my company BatteryBlocs. The website is here: www.batteryblocs.com. It's a way of assembling 18650 cells into batteries of any voltage or amperage using simple hand tools. You can later disassemble them for repairs, upgrades, reconfigurations, or to replace the cells.
Is this a charge only bms wiring install? Or is it charging and discharging bms monitoring?
This is a BMS that you charge and discharge through. Mot of them are, as you charge through them to balance the cells, and they monitor the discharge to shut off the battery if a parallel group gets too low or too many amps are drawn.
The BMS regulates the negative leads to the battery. Can you throw in a supercapacitor?
The short answer is No.
why would you?
14:38 BMS lead soldering
Old tutorial I know, but what do I connect to my load negative if my BMS does not have a P- terminal? Thank you!
I don't know- what are the two BMS terminals?
@@shawname2 Only C- and B- terminals.
@@johnwax9759 John, I would use the C- terminal. This could have been a circuit board printing oversight.
@@shawname2 Thanks, but doesn't C- only go to the negative of the charging source?
@@johnwax9759 I hate to guess, so I would research BMS's that have a common Charge and Discharge terminal. My limited understanding is that this is a less common way of making a BMS..... Good Luck!
do i use common or separate type BMC for ebike (72v 20s 3p 80A continuous, 18650 battery)
Same or separate port
I don't understand the question- can you send me a link?
@@shawname2
m.aliexpress.com/item/32853559525.html?trace=wwwdetail2mobilesitedetail&spm=a2g0o.productlist.0.0.7afa4173mRYCGF&algo_pvid=5892fc59-68a3-4c86-8c6f-bc565985a2e6&algo_expid=5892fc59-68a3-4c86-8c6f-bc565985a2e6-3&btsid=0ab6f82215918848641621843e162a&ws_ab_test=searchweb0_0,searchweb201602_,searchweb201603_
Separate port- 3 wires, charge port and discharge from different ports
Common - 2 wire, charge and dischatge from the same port
Thx for answering
@@gujda101 Oh yeah, now I see. I like the newer style two wire BMS's- Either one will work the same for your application. In a three wire, the charge and power-negative wires are separated, in a two wire, the charge and power-negative are the same. In both, the charge positive and power positive go to the positive terminal of the battery.
Exelent
I have a question: can I use a hobby charger in this case? If yes, what would be the maximum C for charge? I mean, if this is a 5amps battery, can I charge it at 2C amps?
Certainly- have you seen my video about using hobby chargers? The C rate depends on the cell of course, but with all cells you are safe to charge at .5C, in other words, charging at .5 amp for each battery amp hour....
Ok. Thanks for your prompt answer. I have another (2!) question: how can I build a battery with bms and a display that I can measure the battery capacity and cells status? And the other one is: is there a way to turn on and off my battery with a switch? I mean, I saw a lot of videos using small switches to do it. However, if I have a battery pack that can delivery 50amps, I don't think that those switches can resist or can reduce the efficiency of my battery. Do you know what I mean?
YEs, you can double up and use a BMS and cell loggers. You could just parallel the sensor wires. I would not use a DC switch on a battery, it is too likely to fail. I would use a plug instead and just unplug it..... It's bulletproof.
I notice you just tack the wire to the xt60 may be i am being to fussy i set it into the hole in the xt60
Is it possible to use a 10S BMS as a 5S BMS, without the need to buy a new one
No, as the low voltage cutoff would be too high. It would see the 5S battery as having too low a voltage and shut off power.
What is the max dc current these wires and connectors can handle?
You mean the BMS wires? Around 7 amps.
@@shawname2 No, the phase wires. I'm looking wires that can handle around 20 amps DC but can't find them. If you tell the the model no. of your phase wires that would be helpful.
Hi Sandesh,
Not sure what you mean by the phase wires. Here is a link to a wiring gauge chart. It will answer the more general question of what wire gauge will handle what current. www.powerstream.com/Wire_Size.htm
@@shawname2 I need to decide the AWG grading of the wire I'm using to connect Battery Positive to the motor controller.
Max distance between Battery and motor controller = 3 feet, max amperes= 22 amps, Battery output= 48V.
What should be the AWG grading of the wire?
Sandesh- Follow this link and enter your info- and try different sized wire out. You will be good when you get a voltage drop of less than 5%. Then you can upsize the gauge if you want. I am telling you this so that you can use this on all your future projects.
www.calculator.net/voltage-drop-calculator.html
Video is great thanks now I know how an BMS work but your soldering is not nice that could be much better
I realise it's late but i have a question
What's stopping me from pulling two wires from my battery, feeding one directly to the charger and the other to my load trough a flip switch? Instead of the piggyback method used here.
Seems counterproductive to have the load directly connected to the charger when plugged in, because in my application that would enable someone to crank the motor when the charger is connected, whilst the batteries are being charged...
Thanks in advance!
Sure- A couple of points- 1. Charging through a switch should be fine. But cranking a motor- a gas motor? draws a lot of current- and would soon fry most switches. You would of course need a DPDT switch...
It not a matter of having the load connected to the charger, it is a matter of not having to disconnect the load when charging. If you want to disconnect the load when charging, make a connector that you can pull apart. Like an XT-90. hobbyking.com/en_us/nylon-xt90-connectors-male-female-5-pairs.html
Sometimes when troubleshooting it is useful to be able to run the motor from the charger- to see if the battery is dead...
Hope this helps, please requery if not.
Oh sorry, I didn't mean crank a petrol engine. I meant cranking the throttle for a regular 24V 100W electric motor! A decent flip switch should be able to handle that!
English ain't my first language so I apologize for any misunderstandings :|
Hmm. In my case the load is basically nonexistant when no throttle is applied so I would assume that to be a non-issue...
If you have the time, check over this quick schematic of my plan: i.imgur.com/Wr5Hyls.jpg
Hit me up if anything jumps out at you!
Thank you very much in advance!
It looks good SW. The switch is unnecessary, but you know that. Good planning!
Yeah i know, it's just there for redundancy. It's for my nephew after all, his parents would propably want to turn it off ;) Thank you very much for the help!
How to wire the final step of the BMS.
"...A bit of a vise..."?
a battery is a group of cells, not the other way around.
and why are you not using the correct gauge wire 50% out of a 100% for your work, good luck for you. thanks
Sir, your videso are helpful but I do have to admit you have confused me on a few points. Would you be willing to either allow me to contact you or you contact me? I have loads of questions.
Sure, find my email address at www.batteryblocs.com
you are working very unsafe you could easily short this circuit by your vice clamp. very sloppy work.