How to build a safe and better lithium battery WITHOUT a BMS.
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- čas přidán 16. 06. 2016
- Did you know you can build a better Lithium Ion battery pack if you don't use a BMS? Using common hobby parts, you can triple the life of your pack and have an instrument panel into the heart of the battery. If you are considering building a Lithium Pack, consider this option. If you enjoyed this video considering donating to Macklin's school fund. www.crowdrise.com/macklins-ed...
The eloquence, the fine humor and people dare to say CZcams has no good content. Not that you need my compliment, but you're good! I learned a lot.
I rarely comment on videos but I had to this round. This was an outstanding and informative video with a very good option to an aggravating issue. I see this solution 10 fold better than pretty much all standard styles and 95% of any non-standard ideas for doing this. Love it and for sure recommend.
Thanks Drew!
Shawn
I also make a video on bms inspired by him visit my channel to watch the video. in my video you got everything about BMS
Topic cover in my video is:-
1) how bms work 2)how to choose the right BMS 3)how to connect a bms 4) how it's work 5) if BMS take care of series what about the cells that are connected in parallel
this may be the most informative lithium charging video I've come across so far. thank you
Thanks Ken! Hope it clears some of the mystery about charging Lithium chemistry batteries.
Agreed, it validates my work based on what BatteryUniversity says about prolonging lithium ion batteries via undercharging and that BMSs are an unnecessary additional point of failure.
Thanks for letting us in on this. I just went out and tried to see if my ego hedger would work with just 56v without its bms and it did. This will save me lots of money. Thank you Rocket Man
Thank you very much sir. I'm glad that there are people like you in this harsh world we live in. I wouldn't have ever known this if it wasn't for you.
Hey Shawn, thanks for the awesome vid. Making all my packs with this info now and it's making a huge difference! Thanks again Shawn!
Hey Shawn. Excellent video! Your approach sits really well with this retired instrument engineer with a serious DIY inclination. I can't wait to build my first battery pack and put your approach into action.
Thanks Brian!
Thanks for this Shawn I've explained this to many after watching your video a good while ago. I'll be creating 4x29V packs @26AH. Connecting 2 in series & then paralleling. creating a 58.8V @52AH With cell logging like yours & also adding foldable solar panels to the bike. I have a 48V 1000W rear hub on a dual suspension, 300+ new cells. I'm just waiting for my spot welder to arrive which should be pretty soon! Excellent video.
On behalf of everyone involved in 18650 cells THANK YOU sir
Good video. I've found that battery packs last better when cells are in parallel as the cells keep each other balanced. I use 3x 4S4P in series for a 12S 20Ah pack without a BMS. I can split them at anytime for hobby charging but prefer to bulk charge using a constant current 10A LED driver with Max voltage set so that cells do not exceed ~4.1v. I occasionally balance each 4S4P pack separately using hobby balancer. The 4P setup keeps them very well balanced.
If this is indeed more efficient / better balance and longevity why don't battery pack companies and DIY's build their batteries in this manner as you described?
@@connicrow9463 @Conni Crow they do, except they always add a BMS due to the nature of lithium batteries. I was confident on my pack because the sense wires (also paralleled) were very small therefore naturally limited current (like fuse wire). I did end up losing multiple paralleled cells when one went bad, but this is normal in any pack. BTW, as proof, my current bought battery is 13S(7P) compared to the long gone homemade 22S(4P) - I now have BMS security(cell charge limits; cell balancing which really is required as every cells different)
@@MadMatty72 in other words, you got lazy and used a bms. I've been there haha.
Your explanation of the whole charging issue was awesome and I understand much more then I did! Thanks
Man I've been thinking about this way for a while, just came across your video, THANK YOU.
Agree 100%. Your battery is only as good as its lowest capacity block. Once it is full, charging should stop.
There is no point in putting more charge into any other block, its just a waste.
My Idea is to monitor and display each block voltage and auto disconnect the charger when any block reaches 4.2 volts.
Less if you only want to charge to 80%, to lengthen battery life as with Tesla.
Likewise turn of the load when any block is down to around 3 volts.
To really balance a pack it is best to make sure each pack has the same Ah capacity.
What about if i use different brand cells in 16s10+p pack ? still dont need a bms ?
Ok you've made a believer out of me and have made the most straight forward to the point video I have ever witnessed! Thank you battery guru thank you!!
Thank you for taking the time to put together such a non BS video. anytime I am told I have to use something I ask why and if I don't get a satisfactory answer I usually find it is a lawyer insurance company or Corporation.
Hey Shawn, this is the BEST anti-BMS video I have watched so far!!! I don't use BMS myself for the same reason as you, there's no feedback and I don't know what that little cheap and nasty PCB is doing. Most batteries (to not say all batteries) I repair have a problem related to a faulty BMS. The cheap ones don't balance the cells at all they actually KILL cells.. last thing you want is "a device that will unbalance and kill your battery". BMS also makes things unnecessarily a LOT more complex, that doesn't encourage people to make their own batteries!
I made a pack with Panasonic PF back in 2014 and last time I balanced was almost a year ago, I run it hard 1500w every single day, guess what, almost one year later the pack still balanced.
On the other hand I have many videos showing "how to install BMS" because from a bike shop perspective, most ebike users have absolutely no clue about electronics so in this case the BMS is more reliable than some humans.
Congrats for this video, I will recommend to many people here when replying comments in my channel =]
Hey Thanks Bruno! I'm pleased that you have come to the same conclusions that I have. Tell me, how far would you let your pack get out of balance? .1 volt, .2 volts? And what cell voltage do you charge to to be safe- 4 volts?
Hey Shawn, good questions haha.. at work I have to be a bit more strict with balancing as the pack wont be under any monitoring apart from the BMS, most BMS will cut above 0.5v so I try to keep it below 0.2v after multiple cycles to ensure this difference is not growing and the pack is stable.
I do charge my 14s all the way up to 58.8v which is 4.2v per cell, it takes a LOT longer to charge but in my case I performance is more important than range and the pack life. For a regular commuter I would say 4v per cell is all they need, really liked you mentioned many times in your video that charging to 4v you can double or triple the cell life, most people don't even know these things. POWER to the people haha =]
Thanks for your insights Bruno! Experience has led us to the same conclusions!
No bms also gives you more POWERR!!!!!
Good point. It's because the power does not have to run through the circuitry of the BMS.
Thanks Shawn for this great video! I'm now convinced to use a hobby charger to charge my ebike and no longer rely on a BMS. The only small "issue" I see is with the cell logger: this thing will be powered from a single cell and so it could slightly drain that cell compared to the others, thus generating imbalance... Is that a problem in practice? Or are there any cheap cell loggers that are powered from each cell one at a time? Thanks!
As an Electronics Technician, with many years of field experience (yeah, old schooled in TVs, who also keeps up to date on tech) I can vouch for this excellent presentation.
I began watching the video and had to smile when you came to the point that BMSs do not provide any feedback of the state of the individual cells, therefore makes no sense to use them, specially when one cell goes whacky and the BMS shuts down everything.
Thanks for putting it together and to the people who gave negatives to the video, you guys don't know squat about LiIon batteries and basic electronics.
Thanks, I'm chuckling.
It's an old saying to "not know squat" I believe it came from the era of the paddlewheel boat captains making their way up and down the Mississippi. If you didn't know "squat", there was a good chance you would run your boat aground on a sandbar.... Is there a metaphor here?......
hah.. absolutely... those folks don't know jack shit either :-)
Really glad I found this video before I build my pack. I've gone BMSless and have no regrets so far (300 miles of riding so far, and ZERO Balancing needed using 280 used laptop 18650s). I'm waiting for a little 8s voltage display that cycles through the voltages of each series, it cost me a $1, that's the kind of feedback I want.
Yes, once you learn how to go without a BMS you don't want to go back. A BMS is kinda like training wheels for batteries.
Hey Shawn, great to see someone accurately describe those Battery Murdering Systems!
One thing I would suggest though...you can reduce the effort involved in bulk + balance charging like this by just using a balance tap only charger like the BC168. Yes the balance leads/plugs are somewhat limited in current carrying capacity, but if you limit the charge rate to something reasonable it can and does work. I've been doing it like this for over 4 years now.
Cheers
I watched your video 10 times and I rephrased my question again.
1. I'm planning to build my first battery pack and convert to ebike, and you convinced me to spend more on good smart charger.
I looked up iCharger 1010B+ but max output V 40 with 7 A, so by charging not to 42V but 40 V , I will extend my battery life.
Please confirm that 1010B+ charger will be good for 36V 15 amp pack. What power supply would you recommend for this charger? I found Junsi 350 - Outputting 350W at 23A/15V. Will it be good?
2. If I get 10S charger but cell logger can only take up to 8s, can I connect 2 loggers 5 s+ 5s (not physically splitting the battery?????) and have extra port with JST-XH 10s for my 10s charger so I can charger my my 10s5p battery as one?
3. Mr. Jehugarcia, talks about bottom levering batteries, should I then go up on the charger and get PowerLab 8 to do both smart charging and bottom levering of the batteries??
Thank you a lot!
Glad I stumbled upon this. As a “newbie” to this stuff, I couldn’t understand why BMS’ are held in such high regard when 90% of the reclaimed cells I have so far are good cells and bad BMS’ (it seems). My logical brain said “wait! what about safety!” But when I heard the little alarm go off? A little alarm went off in my head. I want to be in control, not a nameless, faceless (silent) BMS. Visions of exploding LiOns ...umm..exploded lol. Bravo! As I tell my customers, “ I like my smart devices to be smart when I want them to be...and very dumb when I want them to be. “ Your approach seems logical. Great stuff and pretty funny too lol.
Thank you, this is exactly what I was looking for. I suspected that the tiny resistors on a BMS were not capable of applying enough drain to actually balance the batteries. There's a reason the hobby chargers need fans to stay cool, and that's because they're dissipating off more energy as heat to actually balance the packs. I also really appreciate you showing how you wire the batteries to split them for charging as 2x 7S instead of one 14S. Hopefully now with EVs becoming more common, larger and better chargers will become available for charging 12S - 16S packs used in EV setups.
I hope so too, but I won't hope for long. If one isn't out let's build it!
can I buy a 24volt 30 amp + battery from you? how much would it cost?
Sacrilege, you mean low quality chinese made BMS should not be trusted to manage your expensive batteries? thats not what the internet told me
Too many people drink BMS Koolaid. Glad you enjoyed the humor!
Shawn McCarty
Yes, that is my name. Do you have a comment Dhirajlal? If so, it didn't post.
Wie wird ein BMS auf ein accu von 24 v gebaut ? Sprache bitte in deutsch
We are battery specialist from Shenzhen, China. Hope we can help you with favorable price using Panasonic cells.
Skype:elsa.chen76.
Email: elsaqant@gmail.com
Mob:86-13414478893
sir, you have no idear how much knowledge you have, please share it with the world, we thank you for.
Thanks Shawn. Coming from an rc background I didn't like the sound of these BMS units. You verified my thoughts and I will be using your charging method on my diy batteries. Full control and monitoring of the charge is the way to go. Hobby chargers have gotten so inexpensive too. Cheers
Please excuse my ignorance, I don't understand how the charger or logger can see individual "cells" when everything is connected together in series. Does it do the math for you and work it's way out along the chain? Could you do the same with a multi meter manually? Sorry for the dumb question, this is all new to me. Is that batter pack both parallel and series combined? 14 long in series, and 5 wide in parallel?
How does the charger target specific batteries? Does it bring everything down to the low water mark, and then charge from there hoping that everything will be even afterwards?
Great questions!
The logger or charger starts with the negative terminal of the battery. Consider that "0". Then it goes to the positive of the first cell. Consider that 4. Then it goes to the positive of the next cell, consider that 8. Then it does the math and deduces that the voltage of the 2nd cell is not really 8, it is 8-4=4. Etc.
The charger charges the entire pack in series. Using the same technique, it monitors the voltages of all the cells. If one exceeds the set limit, say 4.2 volts, it turns on a resistor through the balance lead connected to that cell, and attempts to reign it in. Failing that, it reduces the charge current. Failing that, it shuts off the charge.
Shawn McCarty thanks so much for the response!
@@shawname2 enjoyed your vdo & info, correct me if i'm wrong but in your explanation above, each voltage point being measured w/data logger is that of 5 "cells" that are in parallel, not an individual battery "cell", thus it's possible that over time you would not know if a cell or 2, etc. has opened ( out of the 5 ) and/or developed a failure mode resulting in high internal resistance ( won't take a charge/shows few millivolts).. ( by wouldn't know i mean other than your range would be lower...pack produces less amps, etc. )
Good comment. Yes, it does the math and works its way out along the chain. You could do the same with a multimeter or a voltmeter hooked to each parallel group. Yes, all batteries are made up of cells connected in parallel to multiply amps, then those parallel groups connected in series to multiply voltage.
@@robozstarrr8930 yes, i thought that too, it's a disadvantage of the parallel/series system as opposed to the series/parallel. In the latter it's much easier to determine your bad cell, but seemingly the advantages of parallel/serial outweigh this disadvantage
4.0v saturated cells are 80% charged. If that is not enough range then better to add more cells than to charge to 4.2v which stresses the cells and saturation cutoff is critical.
I agree, and when there is room. But it is good to have the option of still being able to charge to 4.2 in case you need the extra capacity for a long long ride.
It is good for a knowledgeable human to make that choice, not a chip!
You are just dripping with the goods around here. Thanks for stoking the fire to the next level!
Yeah! Be bold and go for it! Just don't be stupid bold!
Great video Shawn, I made an ebike last year using 10 x 6S 5Ah lipos to make a 48V 12S 26Ah pack and don't use a BMS.
I charge using a Turnigy Reaktor 300W 6S charger in two sessions, and as often as possible from 300 W of home made portable solar panels, that weigh about 6 lbs, fit in a backpack and can be laid out anywhere.
The pack is capable of giving 12kW of power, though I "only" use about 1.5kW, and that is plenty!
I just made a couple of extra cells using 16 18650s per cell (~36Ah each) so it can cope with 30A and 50A burst regen, and now gives me 14S, though regen doesn't work until the voltage drops 1/2 an S, as I found out when I needed to brake the first time I tested it!
Yes, I know the chemistries are different, but I charge them individually and make sure voltages are always within spec.
(Just a note about XT60s / XT90s - lipos use the female type, so I'd recommend following that convention for compatibility).
(I put a video up showing my pack, charger and solar panels on my channel if you're interested)
Ok, so just to be sure: you can ''bulk charge both at the same time'' meaning you use the balance charger in another setting in order to charge? And then, when you want to balance charge, you separate the 2 packs and then charge them one at a time (assuming you have only 1 charger)? Thumbs up perhaps so people can see.
YEs, that is it. But you can bulk charge to extend the life of the battery by keeping them connected together and charging both at once. Either with the balance charger- not in balance mode- or a separate charger.
I'll be better charge it at pararel if I only have one charge and leave it charge with alarm on :D
This is an interesting concept! I learned a bunch from your video - Do you think this would work on something like my build on my page? Thanks
-Kage
An electric longboard? Cool. Yes, it would work. The builder would learn about how to build batteries too.
Completely agree with this approach, needs a wider audience.
So glad I found this Video. Working on a Chinese 100w scooter and swapping the Lead Acid battery with 18650's. This was really helpful because I had the same thought. I wanna know what my cells are doing and not just let happen till it fails. So thank you for this detailed explanation why not to use a BMS and what alternatives there are.
Thanks Hard Disk lover, This is a common conversion. The Lithium Ion batteries tend not to have the punch- the ability to dump amps- as the lead acid, but they go further...
when you adjusted the voltage your hand covered it, any way you can re-record it with a better view please.
FYI, BMS = Bristol-Meyers Squibb. Oh, wait, it is Benicia Middle School. Perhaps Blue Mountain State?
Perhaps Battery Mismanagement System?
Is sad i found this comment. I had to google myself to find the definition...
When someone uses insider language outsiders won't understand.
This is exactly what I am looking for. Thanks for the video.
Subscribed :)
Thank you for the video my eyes are starting to open up no BS LOL have a great day Dennis
Watching this in 2019.
Now you can get BMS with bluetooth and monitor cells(ebay and aliexpress from china)
I'm going to assume that the BMS intended for 300 amp charge/discharge is going to have enough balancing capacity to handle an ebike no problem. There is stil the issue of the BMS cutting power mid-ride if it finds low voltage. Price is around 120 USD from china. I am waiting for mine to arrive. I hope it works well. They come with a flat aluminum plate as head sink on both sides of circuit because there are mosfets to pass current on both sides of the board. I will be mounting finned aluminum heatsinks using thermal conducting tape to both sides to keep the board cool. Solves a lot of complication, hopefully it works well and reliably.
Thanks for reading.
Let's see how that works out. Times change! I'd love to have a really simple balancing solution for ebikes. Now I use active balancing on the power walls, that is working out well.
Took me a while to find a "cell logger". For anyone else like me they're called Lipo Voltage Monitor.
What are the cables to this monitor called on ebay?
aaaarneaaaarne JST-XH Connectors
thanks!
Danny Tillotson thanks for the info, I couldn't find them and hoped that someone here would give some clue as to where l could find them. 👍
www.banggood.com/10PCS-9Pin-8S-Terminal-Wire-Balance-Charger-MaleFemale-JST-XH-Connector-Wire-p-1050139.html?rmmds=search&cur_warehouse=CN
sir, you are a legend. keep up the work. so funny to watch you fiddle around. indeed hd quality vids has no chance on you
Great video! Thanks. I'm unclear about something. When you adjusted the generic 2A charger to 57V (4.00V each), why would you use this charger if there is no BMS and you need to use the iCharger to balance them. Can you set the iCharger to only charge to 4.00V?
Battery Murder System
"Wroooong" *Trump like voice*
@@NonnofYobiznes Trump is Gone, and so is 2016 :'(
"tripple the life of a pack with a bms" this assumes all bms use the same balancing methods... they dont. "a better battery pack with out a bms" False. If you take the time to select the right components for your build ..and go down the path of an active balancing/charge redistributing bms... it will be better in any objective measurement of "betterness" you wish for two packs to be compared.
The guy made his case with some products and useful info. Can you share some products and examples?
GENUINE question because I have a 52v 20amp battery that I recently experienced issues with ... guess what it was?
OOOOOOH ya, the stupid junk BMS. the battery was reading ~28v and when I checked it before the BMS it read a fully charged 58.6v
@@atefamriche9531 linear Technologies. You probably need to make a circuit board but you can do things like active balancing during run time or in other words cell groups prop up a weak cell on the fly
That is really a great video. Very good Information. I wish I could learn this battery stuff. Thanks for posting.
A brilliant video! everyone thinking of going the diy route should watch this before doing a build. Hobby chargers a the way to go, its a no brainer!
your I-charger cost more than the battery.
Chargers are 15$ imax ezpz
"Stay within a 100drths of a volt whether you have a BMS or not"..COMPLETELY untru. As a matter of fact the higher amperage you draw the more they will vary in voltage as they are discharged.
"If your battery is perfect you dont need a BMS"..lol..what?..I make battery packs and use Panasonic NCR18650PF cells and I can tell you that after drawing 50 amps of discharge (burst) and an average of 25 amps continuous, they ABSOLUTELY do vary in their voltage and without a BMS the weaker ones in Parallel would hit 4.2 volts first and then get overcharged. Here's a hint; not all cells even quality ones are created equal!!.
Of course the problem with using a hobby charger for balancing is that on the discharge side, the weaker cells will hit 3 volts first while others are at 3.3 or higher, and if you think that doesnt happen, then you have NO real experience working with these cells, and in my opinion this video is very dangerous.
OK! Did I say a hundredths? Let me correct myself then. I balance when my batteries are 2/10ths of a volt out. "If your battery pack is perfect you don't need a BMS" is a thought experiment, perhaps I am wrong to assume everyone knows that everyone knows that no battery is "perfect"- or to be more precise, stays perfectly in balance.
Using the hobby charger for balancing and monitoring the cell voltages with cell loggers to know when your cell hits a pre-programmed low like I advocate is tried and true in the hobby industry. They run very high C packs without BMS's using this technique. The battery packs on my ebike are still working very well after over 20,000 miles and four years using this technique. It takes me overnight to come within three hundredths of a volt balance using my hobby charger, an icharger B-10, and I know this exactly, there is no guessing . I bulk charge to four volts normally and balance charge about once a month.
Thank you for your passion! I think we both care a lot about batteries!
Thanks for the reply...I didnt mean to come off sounding so snubbish...and yes we both have a passion for this..I make and sell battery packs and almost all unfortunately, have to be installed with a BMS. I have gone through many and there are good ones and there are bad ones..I am currently using Supower BMS units and they have so far been ok. Bestech have been terrible for reliability. I personally have used battery medics for my headway 24 s pack, but that's me and not many could do it...I sold the remainder of my headways to a customer and he wanted to do his own balancing but couldnt do it even after I balanced the cells to begin with. Im not saying it cant be done but most cannot ;)
Hey John,
Wish we were in the same neighborhood so we could compare notes. I am sure I could learn a lot from you. Thank you for your courtesy.
Not a problem at all. I also checked out your kits for building battery packs using magnets. I would wonder how much resistance one would expect connecting cells in this manner..of course when building a pack you want to eliminate as much resistance as you can to have the best performing pack you can make.
I agree. I overcome with mass- by building a very large conductor- the higher resistance of 1010 steel. The steel is also zinc plated- which conducts about as well as nickel. Also the distances are very short. This was of course very much in my thoughts when designing BatteryBlocs. All I can say is in practical use the steel does not seem to be an issue. If you have a way of measuring resistance very precisely I will send you some sample Blocs and you can report back.
Hey man THANK YOU! exactly what i was wondering! Cant wait to check out your channel
Enjoyed the video! How would you set up a 60 Volt pack? Split it into 3 - 20V sections or 2- 30V sections?
As someone with a electronics and communications degree Please do not and i repeat DO NOT make one of these on anything bigger then a 4 blade drone. The issues and DANGERS are very real on any none BMS pack after a certain size.
Thanks. I always go with "respect your LiPos". The fire test videos are pretty inspiring. I think the author's approach works fine for small packs but it starts to get harder to manage over a number of cells.
Samir Yeah i agree but the cell he is working is way to big and could easily short out, my quadcopter has 26 amps in storage to use and if i did what this guy is doing it would burn my house down or kill me in the process.
I shorted a 5 * 12V Lead Acid pack (40 Ah) once and the flash blinded me for a few seconds, took a piece off my plier. To this day I thank god it wasn't LiPo.
And I think that every LiPo pack, BMS or not should have a fuse in series to make sure that stuff like that doesn't happen. I was working on the stock charging circuit that was unprotected from factory.
Yeah i work with 2x110 volt battery banks about 2 times a week on faults and issues these things can pull 100 amps in a split sec if you are in the way you are either dead or in hospital.
What he is doing is ok in small units but can in bigger units like the one he is playing with can cause a cell failure and if it goes into meltdown as i call it it's a chain reaction nothing can stop it. Perfect example if this fool gets hit by a car and is stuck under the front of the car and the batteries short out and the bike is on him it's over he will be burned very badly or killed. THIS IS WHY tesla have 6 amp micro fuse on each battery.
.
Having a micro fuse on each cell is a great idea. But no ebike or hobby packs have that technology. Yes the bigger the packs are the more power they have the more potential energy they have- to power your device or if they get crushed--- to have a thermal runaway. Same is true of gas tanks. If you are going to make batteries or internal combustion engines or hydrogen fuel cells know the risks.
I've noticed that people who smoke a lot of dope all act the same.
rob, yeah they a pack of enlightened dumasses
Very comical but great info. I know Jehu doesn't use a BMS on his EV van so neat to confirm when you can charge responsibly without a BMS. Thank you kindly for sharing even though it was a couple years ago - just seeing it now :D
So, just learning some new stuff here... Can this same method be used for larger batteries, such as a 200 amp hour 12v lithium battery for use in RV purposes? I'm guessing no, but maybe you could point me in the next direction for further learning.
Sure. It would just take longer to balance. You would want to use a very high powered hobby charger- look at the top of the line ichargers. I am not sure if it would make much sense to use lithium in an RV, as weight isn't critical.
Sweet! Good to know! It will be for a van, so size, more than weight is the issue. Having to buy 400 amp hours with of batteries to be able to use only 200 amp hours seems like a super poor use of space. Great video BTW!
Thanks Adventurer, Hope your RV project works well.
LOL i use to want to build an ebike but all this catty bullshit just made realize I'd rather die a man who still rode his fucking bike
dude
chill
At no point was he talking shit about sick people.
lol
well that escalated quickly :D
You could never afford an e bike,do they even make them in 3rd world country's
Who the fuck asked about your health and your life, stop projecting and get on with your life.
My girl died of a brain tumor , but I don`t shout and yell about it because some internet RANDO said something about being a MAN..
Shut up, play nice, get well soon, and don`t forget to take your testosterone pills..
ffs..
enlightening! Thank you. I like your POV
Thank you for this video. Good monitoring is much better than bad management.
Shawn, do you have some Temperature vs .I discharge for Li-Ion measurements data? Thx.
Legendary video, have watched it several times.
Super shawn, the concept is easy and you got at very reasonable costs a perfect picture of the state of your battery packs. I ll order some low voltage buzzers and this Icharger (for 6S) and will refer the results happily when finished. Thanks a lot. I was about to buy an expensive BMS 12S ... but know I ll go for your genial solution of the charging problem.
Thanks Shawn , very good video , logical and well explained .
Awesome video thank you. I am new to the e bike world am working on my first build now. I'm a bigger guy and live in a town thats ALL hills so I want to make sure there is enough power to get around without over taxing the system. It first I just wanted low range (around 30 miles) but seeing what these 18650's are capable of I'm not thinking I want to be able to tow a small cart with additional batteries for a long distance trip this summer. I like that you monitor each group and you can turn them off to not draw wasted power. I dont have any experience so my concern is not knowing when to check them. can I run a bulk monitor to measure overall voltage or could I just leave these on all the time without too much of a net effect?
You are the berries! I love the presentation! Thanks!
Awesomest vid I've watched today. Subd!
I learned a lot in this video. Thank you so much. Very well done. Ron
Awesome video It answered so many of my questions as I discover ebike batteries thanks heaps.
Shawn, I have a 400 amp x 12v Li battery in my motor home and its playing up, you gave me the idea of opening it up and seeing if that is the problem, thanks mate
Well sir, you got my attension. Cheers and have a good one :)
Really good information!
I just remembered I ordered 2 x 5s bms off eBay so could I split battery into 3 like I had before an use imax b6 with 3 separate leads but with batteries not connected or leave as is and see how they go .have you heard off a hobbymate cell checker it can discharge batteries got one on way it was only 8£ and can monitor cells too
i've been thinking about this for most of the day today. it must be possible without the BMS. ZACK! now I have seen you....many thanks and greetings from germany
please, tell me more about 17:30 calculation!
supposing one 7s pack, if I use a constant voltage power supply of 28V instead of 30VDC or more, the BMS cannot charge at 4.2V per cell, stop charging each at 4.0V and the number of cycles increase a lot ? of course the mileage full at 4.0V for each charge is a little less than the pack with 4.2V but a lot more cycles are really good.
Shawn - this is far and away the best video I've seen on setting up on 18650 battery pack. I can't tell you how many times I've paused your video, taken notes and implemented into my pack. I decided to build a single pack broken out into 2 (non-mechanically). Specifically the harness to connect the two in series and the cell-logger wiring - great stuff ( I even bought the same balance charger but the 8 not the 10). The only aspect of the video which confuses me is the 8 pin Deutsch at the end (I paused and tried to count the holes in the plug). I have to believe this is an adapter for the 8 pin balance lead, in which the adapter connects the "sensor wires" (assuming you are referencing the cell logger wires) together to something else. I'm just not sure about that last part, understanding that the XT90 is the power lead. 16:30 of your video. Any illumination on that last bit would help.
Exceptional info. Thanks !
Shawn should I set my cut off at 28v or 30v? I have a 36v 14ah battery. And one of the things my new LCD throttle controler ask is what low volt shut off to set at. Thanks.
great vid ...just built a bms free pack took me hours but that fine it works great tnx
Hello Shawn, I have a question. If I split a 10s4p in two 5s4p batteries, like yours in the video, could I connect the two batteries and also the jst connectors in parallel and charge them at once with a smart 6s balance charger?
Great thoughts on this! Thank you sir..
Interesting video!
Is it not possible to solder both BMS and LCD screen like it shows in the video to the same package?
Thanks
I would put money down this guy is right, you don't NEED a BMS, but I am cringing thinking about the number of wires on any of his bikes. A quality BMS could be used with one of the battery log devices to keep the feedback loop.
Absolutely deserves a thumbs up for the video and for leaving an email address! Nice work, great video!
This is a good comment. Yes, a quality BMS with good parallel group monitoring is a good solution. A toggle switch is wired into the negative of the cell monitor. A two to one splitter on the JST wire harness reduces the number of wires. A BMS bypass switch could be used if the BMS shuts off the battery but you still want to go a little further. There are also new BMS's which combine active balancing with the high current/low voltage shut off functions. They are sweet.
@@shawname2 Also, the BMS can FAIL ... catastrophically ... when you are far from home.
@@MrSummitville I so agree- I have had it happen on ebikes when I have been a long long way from home. Had to open the battery and bypass the BMS with a jumper.
Very informative. I have built a 7s8p and 7s10p li-ion packs for my scooter with brushed DC motor. Because I need a 12v source for the turn lights, alarm and other electronics. How will I make the center tap and split? 3 and half S each or 4s and 3s or 4s each? If 4s'es each there's no 24v standard charger for it. Thank you.
Great video, do you have a link for the cell logger? I can't find it with a google search
Shawn can I wire the 14s kit with all connected and use the imax with 6s x 2 leads an a 2s lead to charge in 3 goes still got the bulk charger 54v also
I like it! Thanks for the informative video, Shawn. What model are those battery loggers? How many charges do you typical find you go between balancing sessions? And lastly, is there any reason one can't bulk charge a pack with a standard lab/benchtop power supply (eg a 14s7p pack with the supply set to 57V (~4.1V/cell) and current-limited to 2-3A). I have plenty of power supplies at work capable of that. It seems like it'd be fine, if I'm sticking to 4-4.1V. I'd likely charge at home with a normal charger, balance as needed (monthly?) and charge at work with the power supply. Sound sane?
Thanks for sharing your knowledge & experience.
Welcome!
I was thinking of using a Nitecore 4D for charging and a BMS *just* for using/discharging the cells in a 12v array. Is this a good idea?
Thank you for posting this, very informative!!!
This is the best battery pack video I have ever seen and I have these chargers anyway god bless your common sense
EXCELLENT !!!! ......greetings from Capri island (Italy)
Hi Lauro Antonietta
I've cycled through Italy- one of my favorite countries. Have a sip of limoncello for me!
Shawn
I like the way you think about modularity. The great cost for DIY EVs is the battery pack that gets luxuriously expensive when it gets bigger. The smaller packs are produced in quantity and get cheap. It's important to keep it safe though.
You sound like you know what you're doing and I just wanted to reinforce to random viewers to know the risks and what to do exactly before attempting this.
It looks like good BMSs talk RS232 and other protocols to communicate the monitored values (individual cell voltage and more) or even be programmed/setup. One could use that to talk to a microcontroller and display whatever is needed. These days there's Arduino enabling this for most people with time to spend on it. Not OOTB, I agree.
Or just hookup the "trouble bit" to a dash LED and have the microcontroller/laptop setup at home for debugging. Not better or worse than the "Engine light" + OBD devices on gas cars.
I like the hobby charger approach as it's pretty safe but I'm at 16S and it already got somewhat cumbersome to manage daily charges. I made a 16 Ah pack out of Multistar 4S bricks.
Currently charging on a unbalanced charger for the whole pack, no BMS but only because the pack is new and I monitored close per cell voltage in the first 5 cycles.
I'm installing a higher end BMS in the next month or 2, so when they age the BMS will shutdown if something abnormal happens and I can connect to it and see what's wrong (or check the pack manually). I made my pack removable exactly to make this sort of maintenance easy.
But yeah, not too surprising that the cheap BMSs do a bad job -- we get what we pay for.
great vid. Helped me better understand a few different concepts I was kinda grey on before
How about programming a VESC or ESC to in place of a BMS and use the BMS only to charge the battery by passing the discharge rate? Is there a battery balance charger that can balance charge 10S or 12S batteries? I've only found balance chargers for up to 6S.
Excellent video Shawn! truly a big help!
Thanks! It's surprising to me how many people are interested in this.
the vruzend guy says I n
eed bms also the nkon supplier of the cells too.i beefed up the wiring after first run so I'm not sure now.when first run the batteries were not at full charge.but after bulk charging the green light came on the charger but still not up to 4.2v but u suggest say up to 4.v okay shawn?thanks.steve in uk
1st class info , thanx Shawn
Excellent video, thanks!
I've been looking forward to making a battery pack for an ebike conversion and I was initially going to try to find a high quality bms, but since I already have a hobby charger I thought I might as well use that and save some money. I'll be building a 12s 3p pack split into two 6s 3p so I can use my 6s charger.
Thanks for the video Shawn, would say it's the best one on youtube re the optional ways that you can maintain these batterys, i have always had doubts about the Bms and as you have stated they don't show any readouts on the actual condition of any individual cell , hence and when in use it is a fly by wire experience hoping that you don't get the sickly stench of battery cells cooking.. thanks again mate, it was a pleasure watching this video..
Hi G Robbo,
Glad you enjoyed this video. In my shop most of the battery failures I see are from failed or underperforming BMS's. As battery packs get bigger and cells get older BMS's work even less well.