Bro, I don't have a Surron, or any e-bike... (right now i don't even have a bicycle), I've never built a battery-pack and yet i find this video very interesting, with lots of information. You apologized many times for the long form of this ... tutorial, but seriously, this is a very detailed video, and it's not that long, considering you are sharing the knowledge acquired through months of research...
@@Q36BN thanks so much! Appreciate it! 3000km so far on that battery pack in my new Surron and, knock on wood, so far everything's working perfectly with it.
I had always used nickel strips for all 14 packs I built up until this one, but in my research I saw the really high-end battery builders were using these copper/nickel bus bars. So then began the long, arduous search to find them!
This is a great video. Thank you so much! I own a Talaria Sting R and have been looking into upgrading the battery. I have built a few packs before and I'm seriously considering building my own for the Talaria as well. I have been looking for this exact video to push me over the edge and get going 😅 And I totally agree with you, the worst part of buildning a battery pack is to solder thoose thick wires!
First of all, this is such an amazing video. Definitely something personal should watch before making a high power pack. @1:27:00 there are two different ANT boot up wire type: 2 black wires are just connected to a momentary on switch, normally accessible on the outside of the battery case. Red and black wire needs a 3v-5v source. Worthless in most cases. Lol I have both versions. Since you installed your ANT correctly, not cutting off 3 of the 4 power cables that ensure current is distributed correctly across the mosfets, you might be able to get longer times at higher amps. As you can see in settings, there are 3 discharge current zones, each with its own time limit. Zone 1, 0a to max continuous, no time limit. As long as the MOS temp doesn’t get hot you can bump this up some. Zone 2. Max continues to peak. This has a time limit. You can set it to several minutes if you want. Zone 3: peak discharge to short circuit protection. This can be set for a few seconds just to cover a minor surge from the controller. Zone 4: short circuit cutoff, normally set in microseconds. Should be set as low as possible that doesn’t hinder zone 3, but high enough to allow pre charge of the capacitors in the controller. Just monitor your app for temperature and test it when doing the current limit, but the ANT normally under rates the values. It does have thermal protection that will shut down the BMS but it’s important to limit current to something that takes several seconds to reach overtemp so the BMS can shut down before frying. Of course you have to juggle between the BMS and the controller settings so there is no conflict. I use fardriver with boost (which also has a timer) so my normal line current is set within the ANT continuous amps zone and the boost current is in the peak current zone (2), with a time limit shorter than that set in the ANT. I think if you monitor the app you will see the ANT stays cool as a cucumber in normal operation. To limit heat in the battery and BMS, after the first top balance, you can set balance current to 20 milliamps and it will still do its job and not make much heat.
Awesome information! Thank you so much. I've been in communication with Ant, and they now have a great BMS for these Surron/Talaria packs: 17-24S, 220A continuous/ 550A peak, and small enough to fit on top easily. Wish it had been available when I did this build. Next time! antbms.vip/product/ant-bms-17s-24s-50a-380a-smart-52v-88v-lifepo4-li-ion-lto-battery-protection-board/
@@CoolWatts , yes, ANT has made huge advances in just the last few years. They are dirt cheap and very reliable and available in power ranges for the biggest controllers made for ebikes. There are so many ways to set up balancing on the ANT for my EXGF I set it to automatically balance each time it’s fully charged. Basically default settings. But for my own I disable automatic balancing by setting the prerequisites too high, and then I periodically initiate a balance to 0.000v differential. Then I do a health check, checking voltage sag at peak amps, and the cell differential at peak amps, then discharge the pack until resting differential is 0.100v, which generally means at least one brick is heading South. Making note of the cycle AH change which should be about 50% of the battery AH rating. Then fully charge without allowing balancing. The first time its to get baseline readings. I would expect your pack to have some quirky cell differential jumps under peak load every 4 cells since there is a copper wire between this cells instead of directly tab to tab connection. And resting differential after full charge should come back to within 0.002v differential. Then I just monitor that differential at top balance and once it gets over 0.005v i will balance to 0.000v again and start a fresh monitoring period. As you can imagine only a small percentage of people even care whats going on in their battery but since you took a lot of time to make it, you might be ine who wants to see how its health is trending. My health monitoring showed me some bricks I damaged during construction (burned holes in the bottom during spot welding) were slowly increasing their self discharge rate, so I was able to teardown the pack before it got out of hand (cell self-discharging fast enough to get hot). One of your viewers made a couple of 30a 20AH lipo packs with ANT BMS but still waiting for the test results under load.
Was thinking of doing the exact same and Iam really happy to see that somebody else went this route and provides the parts for DIYers :) Still, I´ll purchase a battery from a known builder here in Germany, as he manages to fit 22s12p with bms in only 38cm!! Ofcourse, no spacers but you get so much more energy in that I couldn´t care less.
This may sound a bit insane lol but You should TOTALLY do an online class showing people how to make a battery from scratch while being able to have someone knowledgable on the subject (you) there incase they come across any questions or issues. Something low commitment like once or twice a week for 2-4 hours or so... You could make a list of supplies and tools needed ahead of time and then just walk the class through the steps and double check their work to make sure they are doing everything properly as they go. I know I would 100 percent take a class like that as long as it was specified for the light bee and I know a few people that have shown interest in building their own batteries that would likely be interested in such a class. I know this video shows the steps but I think that while many of us want to build our own batteries I think many of us are worried about making small mistakes that could have potentially serious repercussions. Having a “teacher” so to speak would make people like me much more comfortable and confident in our final product. And since like you said the price for making a battery is about half what the top companies are charging, you still have a good amount of wiggle room to choose a price that you feel is fair (per person) and still saves the students some money without doing it for a price that’s unfair to you. You could even do it as a one on one kinda thing and charge people by the hour as you may have some people that only have a few questions and others that would need a full walk through.
For the connection on the bottom of the pack, could you lay the bottom of both sides end to end, weld a double length copper/nickel plate, then fold the two halves together? I've done something similar with nickel strips, it could negate the need for the soldered connection.
Super impressive, those bus bars are pieces of art! The longer I look, the more impressed I am by your knowledge and design choices. One thing that surprises me is the sizes of the conductors. Have you calculated the conductor cross section area across the pack, BMS, and wires? The wires to the plug seem to be 6 gauge, which is apparently around 13.3 mm2. Is that really enough for 325 A? I suppose it's fine at peak load but not sustained. Anyway, point being, I think the cross section area differs wildly from place to place so have you not been overthinking the bus bars? Another edit: so they are overkill, 0.3 mm x 140 mm = 42 mm2, that's way bigger than your 6 gauge wire. But they're super beautiful.
Thanks! Agreed, those bus bars are beautiful, too bad they're hidden in the final build. I think 6AWG is fine for these short lengths, other batt manufacturers I've seen like EBMX are also using 6 gauge. The bus bars should definitely handle more than 300 amps, for now I wanted to conservatively state 300 as that's the value the manufacturer has tested them to so far. I hope to test them a little harder!)
Great job on the video! Very good information presented and covering safety was a big plus. For some reason none of the cool watts links are working for me. Thanks!
Привіт з України! Дуже крутий пак і надзвичайно професійна робота. Після війни, якщо виживу, буду будувати собі Ebike, тож батарею буду робити по твоєму мануалу. Дякую друже!
Duje dyakyu za commentary! I'm American but live in Kherson, can't wait to go back home. Soon! Good luck with your battery build. To victory. Heryoam Slava! 🇺🇦
You should have glued the battery together instead of using clamp connectors to save on space. You would have been able to get more voltage out of it for the same form factor dimensions.
Regarding having space between cells being better for cooling? Unless you have actual airflow moving through the battery it will most definately have inferior cooling. Still Air is far too good an insulator vs metal to metal battery case heat conduction which at least should provide some heat transfer to be cooled by the outer casing... if.... the casing was designed to be in contact with the batterys sides.
Great video even for others building a Battery! I am planning to build a 13s4p pack with the 50s. Max Current will be limited to 50Amps (12,5A/ Cell). Do you think I can use the 50S for this case?
I just want to comment that it is incorrect information about gluing your pack and not being able to replace a bad cell. This is false information and you can replace a cell in a bad pack and I have. You can remove the cell by just knocking it out of the pack, the cell will come out of its wrapping by knocking it out. Then you just carefully remove the glue and remove the wrapping left in that cell hole and insert a new cell. I have done this before on a pack. The cells are not so tightly glued together and there is a bit of space to work with. I even had packs I messed up with and just unglued the whole pack fairly quickly with isopropyl alcohol. Isopropyl alcohol just kills the hot glue and unsticks it very easily. This is incorrect information and you have a lot of things you can do to replace a bad cell with just a little bit of time and I have done this. I recommend to glue the pack together because you save so much room and don't need a pack sticking up out of your bike and can keep the bike looking stock. The heat is a non-issue because these packs don't seem to get that hot and I've used packs glued together which never had any issues due to heat.
@@CoolWatts Yeah, it seems difficult but the cell just pushes right out of its plastic wrapping. These cells actually have quite strong walls. Probably best doing it outside just for safety. I do believe I applied some Isopropyl Alcohol to try and loosen the glue but the cell just came out of its wrapping. Thinking about it, to make it easier, probably should have cut the wrapping at the edges of the cell so it just pushes right out easily, I bet that is all that is holding the cell in is where it wraps around the edges.
Hi, thanks for the video, so much knowledge you share! How come alot of battery manufacturers use samsung 50s here in europe? I'm waiting for a 72v50ah battery with 50s and I'm quite scared now 😅. Is it still ok for 15kw ? Cheers
Thanks for your comment! Yes, I suppose I'm pretty hard on the poor little 50S! 😂 50ah means 10 parallel, so you should be ok pulling like 150A from the pack. 200A would be 20A per cell, which I would make a momentary peak, not continuous. Maybe it's not too late to cancel the order and build it yourself?!!!! Now that you know how to do it) Edit: I thought the same thing, why do so many use the 50S, and not only in Europe? I think it's a false economy - thinking you can get the higher capacity without any compromise in either power output or cycle life. Obviously Samsung had to make compromises to get the higher capacity. And I think they are falsely advertising it as a 25A cell. It's like - you want big capacity, big amps, and low price? Pick two. The only cells now that really provide both are the P45B and P50B. 45 is 6+ euros, and 50 will be 10-12 euros!
Thanks alot for your answer. Honestly I'm not ready to go through the process just yet. I guess I'll stick with what I bought, knowing it might not be the best cell option. At least when I'm ready to get building, I know alot more about cell choice, thanks again. New question in my head now is, given the tight space, how do local manufacturers fit 20s10p in such compact cases ?
Yes! I'd love to speak with you about developing a higher Amp capacity BMS specifically for Surron/Talaria that fits within the case dimensions. Email: support@coolwatts.co
Kind of. At full charge it's about 12kW continuous. That 325A is rated for 10 seconds. In the Ant BMS app, I saw an adjustable cut-off limit of 200A which I believe is for 30 seconds. Haven't even finished the bike yet, been waiting 2.5 months on wheels, and it's still winter in Ukraine. Obviously the limit is related to heat, so will see how it holds up under real-world riding conditions. Good thing is you can monitor BMS and cell temps via the app. But yes, definitely the limiting factor in this build is the BMS. Sucks the 575A can't fit in there. It might be possible if the BMS went in a separate "appendage" box on the side, like some do, but I'm not a fan of that design. Edit: would be great if Ant made a higher amp BMS with the same 147mm length, but a bit higher or wider. That would still fit in the Surron case. Say, 200A/400A would be great. Need to ask them about it.
Amorge sells packs I've seen for about $300-500 above parts cost. But I can't speak to build quality, safety, if they use genuine cells, copper/nickel bus bars, etc.
great build next time i would follow your advice ! you think i be ok with a 50s pack 20s 6p for a bbshd 3kw peak already bought the cells too late too cancel
very nice build, very clean, but i dont understand the cells choice. They give 20a each but only have 2500 mah. Why not go all the way directly to 21700 molicels p42a or Samsung 30T? You would get insane discharge, very high capacity and insane charge rate. If you want to stay in 18650 there is Samsung 30Q.
Bro, you should have made the bus plate for connecting the two halves of the battery as one solid piece: first you would weld the entire battery in one piece and after that simply fold it in half. That would save you the hassle of soldering the two halves together, would save you space and would eliviate any mechanical stress from the bus bars if the fold wouldn't stick out passed the cells when folded. By the way, can you share the info on the manufacturer of custom bus bars? Wanna squeeze a battery pack to my kickscooter, and need a flat bus bar from the positive end to the bms end of the battery, since wires wount fit (
I thought about doing it that way. Saw one guy did this. But I don't like the mechanical stress it puts on the welds, and I worry about doing a hard 180 degree fold/bend in 0.3mm copper. The wires only add about 4mm, and if I ever need to take it apart in the future to replace a bad cell this way will be easier.
Hey, im thinking about making one of these; instead of soldering the two plates on the top with wires could you just weld a copper plate to attach them instead?
Hi, it's 2880 watt hours, which is about 50% more than the stock Surron pack. You could get a bit more range/capacity with the Molicel P42A or P45B. The bike I built from scratch and haven't ridden it yet to test range, but I will. It's still winter where I am, and also I've been waiting on wheels for 3 months.
Update - tested range a couple times, and I'm getting about 80km. Riding on average 50-60 km/hour. Honestly, I was expecting a little more, but it's still not bad. P45B would add 10%+ to that.
@@CoolWatts awesome. probably gonna wind up ordering from amorge right now, just because i need a battery asap. but def gonna look into building some in the future. this video was SOOOO helpful. you dont even understand. thank you so much for the time and effort you put into gathering this info. seriously has everything anybody could ask
@@Martin-e8g zero complaints on my amorge. got the cheapest 72v they sell with a qs8 connector. also got a ko nano on sale. so im about 1500 into my whole 72v setup
The 2 absolutely reputable sellers: - Europe: nkon nl - US: IMR batteries I'll also be selling authentic cells on the coolwatts site, in sets of 180/198. But those can only be shipped within Ukraine. coolwatts.co
Nice vid! Some remarks/suggestions for other builders: - if you are building for max power (amps * volts) instead of range, you could opt for Samsung 30T instead of 40T. The 30T can handle more amps; up to 50A is possible during acceleration bursts whereas 40T can provide up to some 40A or 30A without too much voltage drop. At these high current levels per cell, the 30T actually has more capacity/higher volts than the 40T (look at test curves >30A). This way, you can create very powerful very lightweight batteries! - you should always design for off-design situations (contradictio in terminis..) where the battery is failing due to overheating. So indeed cover the places where you run the bms wires (also small ones) with fire resistant paper, and cover each wire with its own layer of kapton tape. Preferably use heat resistant silicone wire for all wires, also the small ones. Always install temperature cutoff sensors (ant bms has them as well). These measures buy you a little more time when things start to overheat. - if you are using simple rows with parallel cells, you don’t need spacers or glue at all. Just wrap each row in a layer of kapton tape, and then wrap all rows together using kapton tape as well. The spot welding and/or soldering will keep everything firmly together, and if a cell ever fails, it is much easier to remove and replace this cell when everything is not glued or clicked together with spacers. - the bus bars look like a nice and easy solution, but if you are planning on running 50a through each 30T cell like me, I think the resistance is still too high. I would suggest soldering copper braided wire in series on top of each cell like I do. If you solder very quickly with a large powerful soldering ion + cool the solder with a wet towel immediately after soldering, the cells don’t overheat and are not damaged. I have built all packs in this way and all rows have full capacity and have lasted for years already. But be very careful not to melt a short; please know what you are doing and use heat resistant paper spacers for the plus side of the cells. - if possible, please always install an active balancer (based on capacitors) in addition to the bms. The bms is very slow and bad at balancing rows, and only balances at the highest voltage level. A balancer always balances also at the bottom. To this extent, attach an extra set of ‘thin bms wires’ for the active balancer. If you attach an on/off switch to the active balancer, you can prevent it from draining the battery when it is stored for a prolonged period of time. These are just my experiences; your vid is already very helpful to others!
Regarding people being able to sell packs for cheaper, most likely it means they were able to get hold of rejected, unused cells, factories that build commercial e-bike batteries, will discard entire pack if there's one bad weld, so like 50 cell pack, will have 49 good cells. When I was a teenager I got hold of a guy that buys such packs from a guy from a recycling center that gets entire pallets of rejected packs from big bosch e-bike factory. I was then selling those by itself or building packs. Unfortunately some guy crashed his RC plane, the pack lit on fire, the whole model burnt to crisp (pack design was focused on lowest weight so wasn't in any hard case just shrink wrap), and he smeared shit all over me on the forum, so I had to put an end to my side hustle.
Hello very informative video! I saw it yesterday and i wish i would have seen it earlier, 2 days ago i ordered 225pcs Samsung INR21700-50S 5000mAh - 35A batteries for a 20s 10p high power pack for my surfboard that has 15kw continous motor and 25kw max. The 50s cells are rated 35amps like the 40t so i am a bit confused here. However the cells arrive in 20days at nkon so i can cancel the order. I haven´t done a battery pack by myself yet and i am thinking of better get one made. Do you have a good manufacturer that you can recommend?
@@SpencerGaming7580 thanks. Timely message. I'm just finishing a huge comparison test video of ALL the popular high power cells, including the 50S. As long as you're pulling no more than 13-14A continuous, with occasional peaks of 23-25A, the 50S performs well. Like riding a Surron on the trails. I imagine in your application, though, it will call for longer sustained high loads, yes? In that case 50S isn't good. Molicel P45B is much better for high amp draw and they have recently come WAY down in price. From Nkon also. I'd suggest changing the 50S for P45B cells.
@@SpencerGaming7580 72v * (10*13A) That's 72v * 130A = 9360w. That's the most you should run a 20S10P 50S pack at continuous. Yes you CAN pull more amps from the 50S. But they have huge V drop and get very hot (I saw 73C after 3 min). They're designed for high capacity, not high power.
@@SpencerGaming7580 either build yourself, components from Https://CoolWatts.co Or buy a P45B pack from Amorge www.amorge.com/ Can contact them on Alibaba too.
It's only "cheaper" if you don't value, or place very little value, on your time. Questions/analysis to ask - What is the hourly wage you earn at your normal job? Is that more or less than ~1/2 the cost of a pre-assembled pack? Over what time period? Most adults earn more at their job than the amount "savings" offset by building your own pack.
Excelent video !!! I have different bike and battery and does not need to build a battery but your video is so great that I had to watch it till the end :) Do not appologize for the length of the video, you shared a ton of useful informations and that takes time, it is much better this way that a short video. Plus this is a perfect example how to make an instructional video, I have to learn a lot :) Great job, keep on ! Subscribed.
I have a few DIY ebikes and love them since I can use a small gas generator in a trailer behind me and a fast charger to extend my range significantly depending on our average expenditure of the battery. On ECO mode the battery use is very small. More importantly for my Talaria I can't figure out a way to bypass the element that keeps us from running the ebike whilst riding. I was hoping you might know how to do this???
@bigkick86 P= V x I (Power =Volts x Amps) If you have say the same 6kW as stock but with higher voltage and lower amperage, In theory it should run cooler due to amperage being responsible for creating heat. How much of a difference it makes to make it worth doing, I'm not so sure.
Ant bms is actually a great bms; their bms-es are powerful, reliable and very customizable through the app. You can set the desired start and stop voltage for balancing. Balancing is max 200mA in total i think for the 300a peak version. It is not active balancing, so it is better to add an additional active balancer based on capacitors if you can find the required space in your build. The app shows voltage levels for each row and also in total. It also shows total power draw, which is very useful if you want to calibrate a custom shunt resistor for your system, e.g. a modified shunt in your controller or a separate shunt for a cycle analyst. Ant bms is the go to bms for all my high power builds!
