Electric Motorcycle Build - E-Bike - Gen II, Ep 3: 77 Ah Battery

[@IanKing-zz5de]

Grey stuff is "Gap Pad" it does allow a good thermal contact to the outer case, which air doesn't give you, while insulating electrically.

[@JamesBiggar]

Thanks. No one else seems to have a name or source for it. Looks/feels very similar to silicone putty. I would question it's thermal transmittance ability if it was made of silicone. Not a good material for thermal transfer.

[@benharris4436]

@@JamesBiggar An example product is Laird tflex HR400. Other similar ones on Digikey. Tacky silicone sheet, modified for good thermal conductivity - 1.6 W/mK vs 0.03 for air gap.

[@JamesBiggar]

Nice. Not arguing an air gap is best, just questioning the logic behind using silicone. Without modification it's notorious for having very low thermal conductivity, lower even than air. Works great for apps that require high heat resistance. But if it's modified to be more conductive and it works, then it works. I might just buy some larger sheets and give it a try 👍 www.engineeringtoolbox.com/thermal-conductivity-d_429.html

[@benharris4436]

Just be careful that not all the pad materials are as electrically insulating as others. I think most with ceramics/aluminium oxide are in the megaOhm ranges, but the even higher thermal conductivity sheets are also very electrically conductive.

[@Rem_NL]

@@JamesBiggar Thermal pads are very common in PC hardware. It is used for memory modules in graphicscards, ssd controllers etc. These are fused with thermal conductive materials. I doubt its very useful in your case though. The pad is very thick Almost 10 mm by the looks of it. And it is connected to a slab of aluminum without fins etc. I won't expect it to do much in this case, maybe a 4, 5 degree C temperature difference at best.

[@strix9862]

holy cow man! I built a battery super similar to this same different cells but still Li-ion, and I used the Grid cell holders to space them out but used the exact same copper bar method so that I could have screw terminals on a Li-ion pack. It is also for my electric motorcycle I built for my senior project in college. Great minds think alike!

[@daver.236]

I dig your stuff man. It's educational and has shades of a "This Old Tony" vibe that is really easy to watch.

[@yankeedoodle7693]

shades of tony- he never stops talking

[@NIXUSfps]

Mate that was pretty satisfying to watch GL on the rest of the project

[@DonQuichotteLiberia]

Hahaha, I never thought I'd use these words to describe a battery, but this is a thing of beauty! Very nice explanation on all the thought and engineering tradeoffs that went into building it.

[@greghanson-w3d]

exactly the details i was looking for. ive been studying electronics long enough to understand the points. drawing from the middle is one of many fine points that you make. essential knowledge.

[@mcksysar8620]

11.38 it's always a good practice to heat the copper before bending it. This all process seems a lot of work! Thanks for sharing!

[@JamesBiggar]

Saved almost $2k though 👍

[@raffaellobottoni871]

I agree, this process is called "annealing" and makes it more ductile in case it needs to be preformed. In any case, I was impressed by the competence and explanation of each phase, congratulations indeed!

[@viperbite18]

You did a much better job at pulling the strips off the cells than I did my first few go arounds tearing cells down. Ill have to try the chisel method!

[@Cerberus984]

Cool project, if you plan on using more powerful motor battery consider the BMW I3 and look for a wrecked one as carbon fiber frames can't be realistically be repaired. Each NMC chemistry module is 48V × 8 per pack = 384V nominally rated as 360V. Stock motor specs of 125KW (168 hp) and 250 nm torque (180 ft lb) that could theoretically have significantly higher output for 5 to 10 second burst mode. Breaking down battery specs.. 125,000 motor output ÷ 360 nominal pack voltage = 347 amps 48 volt module × 347 amps = 16,656 watts ÷ 750 watts per hp = 22.208 hp capability per 48v module

[@t3chn0w1z4rd]

Wow. What a thought out battery setup

[@cloudpandarism2627]

i am shocked how much patience you have dremeling every single cell and THEN sandpaper it! wow... i would lost my mind after 20 of those. 🤣

[@JamesBiggar]

Lol, super monotonous for sure. I can't stand tasks like that. But with the cost of new M50lt's being $8/each at the 18650 battery store vs paying $600 for three of these used modules that still have >98% capacity left, that works out to almost $2k in savings with extra parts to boot. So I put up with it lol

[@andyfumo8931]

At the end when you explain the bms settings, there is a pile of cells unused on the table. Are these extras or duds? If extra why not add them?

[@RoCkShaDoWWaLkEr]

Thanks for this video! I just bought an Emotorbike that has a 72v lead acid config and I've been looking to upgrade to a high AH lithium ;but prices for premade are over $1000 CDN ;but I can buy 2 36v 70AH battery packs for under $300 and wanted to strip then rebuild them into a 72v pack. This video is exactly what I've been looking for, thanks so much!

[@andyfumo8931]

You can also just disconnect the bms from both packs and run to a new 72v BMS, *cough* bac4000..m

[@bradley9856]

That's a beautiful battery. Good job with giving those cells and cell grids a new use. decent cells as well. I recently built a 20S6P pack with samsung 50S cells, was good fun

[@marcbrasse747]

Wow! Very impressive! Only a few years back such info was very hard to get hold of. I have built a monocoque chassis for my electric motorcycle and want to fill it with a 15 to 20 kW set. I wish you where my neighbor.

[@maryckbuilds]

Thank you for your uploads! I learn from them and aspire to take on projects of this level

[@LosZonga]

Hi James, awesome built - like always - nice you get to use the soldering machine. I just wait to see the full project. Best of luck!

[@jeffmcdonald101]

So refreshing to see a maker on KZbin who can solder like a pro. Very nice work!

[@JamesBiggar]

I'm no pro, just an ambitious enthusiast. But thank you!

[@pullbackbaby]

Watching this video inspired me to build a kweld. Will search your other uploads as well. Great great great channel 😮😊❤. Thank you.

[@zblackrider]

Nice work. Love the Brake.

[@varweg]

Hooray! New episode! Thank you for the video

[@Bobisuruncle54]

Great video! Can't wait to see how these perform in your bike.

[@ben5676755]

Love the vids man. Just to have to put this someplace (even though it's probably obvious from the vid). When working with batteries like this, be extremely careful. If a battery vents it's not a fun time.

[@MrHeraldx]

Great Video I appreciate the amount of work and time you put in this video.. 👍👍👍👍👍👍

[@SuperCycle-23]

You really do clean and safe

[@WayneMcNab]

Fantastic job!!

[@PPiTzone]

Very nice work! thanks for sharing

[@JamesBiggar]

Thanks!

[@CrossWindsPat]

Wow 77AH that thing is gonna have over 100 miles of range!

[@MarceloSouzaOficial]

Very Top.

[@jaydavis4752]

This guy is amazing 👏 I'm not even a techie but I could follow this and probably get it right.

[@JamesBiggar]

Thanks!

[@alteredexistence4115]

Great video...I wish I could retain half of the knowledge you have on this. I would love to be able to make another battery for my e-bike instead of the $1000 + that it costs to buy another. I also wanted to build one for an electric trolling motor but I don't have the technical skills for it.

[@Barncatfish]

Very clean work, professional presentation.

[@stevebricks]

Hey here’s a pro audio tip. Not sure you even care. You can use a noise gate to limit the background noise. I notice a few scenes with hum. That can be removed as well very simply wirh a click. Look into gate and hum removal plugins. Hope that helps.

[@JamesBiggar]

I've been using noise reduction in Audacity.

[@MadebyBelarus]

Шикарная работа, Джеймс!

[@JamesBiggar]

Спасибо!

[@ИванИванов-з4о4ф]

Большое спасибо. Класс Качественно

[@REAPER85151]

wow nice found thank you for sharing this👍

[@JustAnotherAsianGuy2]

man your smart ..... kinda cool

[@osa8osa]

Thanks Man, this video help a lot... Jemes you are the Man ♥️

[@venkateshbhat9890]

Waiting for part 4

[@donhaywood6542]

Nice Video. You know your stuff....but way over my head.

[@ssangnomsekki4413]

멋지네요.

[@Codyhumburg]

James check the spec sheet on these particularly the c-rating at the temperature you will be using them. I ordered these too after watching your video. Just want to make sure these will meet you demands.

[@JamesBiggar]

Yes, already did - important part of the planning process ;) They'll be fine. Thanks!

[@Codyhumburg]

@@JamesBiggar I thought so too. I saw this video and went to battery hookup so quick. I’ve been sleeping on them since the stoped carrying the 32650 Lifepo cells. These modules are a great find!

[@mikejf4377]

I would like to know where you purchased the nickel roll from. Thanks again.

[@tylorbray]

I was jus t on battery hookup yesterday looking at these for an emoto project lol.

[@dr.projectx5142]

Nice. Will be looking up the spot welder you used for making the pack. Plan on getting one for when I build my own packs.

[@benjaminhuescas5130]

instead of two dusk bars for the positive side, could someone put a awg wire at the bottom so it will still equally share the load? Just wanted to know for my battery build!!

[@JamesBiggar]

Yes, as long as you size it accordingly.

[@benjaminhuescas5130]

@@JamesBiggar what you mean by sizing? Does that mean getting the correct awg number for the battery?

[@alanrothschild8996]

when the apocalypse come, I know one more guy to be with now. We will increase our tech tree and make our own bike 😆

[@rickrandom716]

I just picked up a 2011 zero motorcycle with no battery. This would make the perfect battery for it. Im upgrading everything motor to a brushless and controller to a bac8000 apt750 display

[@Edmorbus]

Thanks for sharing

[@JamesBiggar]

Thanks for being a long time subscriber!

[@Rem_NL]

at 01:00 it sure looks like thermal pads, but the usability of conducting heat seems like it wont do much. The thickness of the pad suggest that there wont be a whole lot of transferring, and the heat sink is just a slab of aluminum (no fins etc). It might lower the temps by a few degrees C but is that really needed?

[@bentheguru4986]

Grey stuff is thermal conductive pad that is electrically non-conductive.

[@sudopk]

Any details on the bms? You mentioned that it handles 30 or 40 amps. I bought one of these packs and it will be great to be able to use this bms since it seems high quality and built right in; but I can't seem to find any details on the wires; and do not see any voltage on the wires. There is not much marking on the the bms pcb. If you are able to do a video of the bms, it will be extremely helpful. Thanks.

[@TundeEszlari]

King video.

[@timwegman5776]

Great information thnk you😊

[@JamesBiggar]

Np, thanks for watching!

[@Willalvers]

One clean pull and whole strip comes off ^_^...i must keep my technique a secret 👀

[@JamesBiggar]

They didn't do a very good job. Can't pull my strips off like that after using the kWeld though ;) kzbin.info/www/bejne/hGSwqZdvaZZ5itk

[@uilleamgilvoni4295]

about to make my order for 2 packs of this batteries to make a 72v 55ah for my electric motorcycle project. is there a chance that you could share the 3D printing designs? I would love to make it as clean as yours!

[@shawnd567]

Anyone figure out how to use the built in bms?

[@akinnon2000]

Very professional build thanks for the video. Is this a homemade spot welder from headways cells ? Do you sell the schematic ? O_O

[@scottjoyce85]

any hints on the future of all those headway cells?????

[@DKLVE]

Excellent work....for what bike is it?

[@gabichone2319]

Is it possible to make a case that will transfer the heat to some kind of cooler, to make a better cooling, then place a radiator and a hater pump, to maintain flow

[@JamesBiggar]

Yes. I was wrong about the grey material in the video, it could be a good candidate to bridge the gap between the cells and a heat exchanger, but I think it should be thinner for better heat transfer like another user pointed out. I used liquid cooling for the buggy motor too, but the motor was already built for it. I just had to add the pump and radiator. This is quite a bit more complicated, but I'm considering it.

[@cleyton3657]

Sensacional!

[@Antoine-ek2mf]

Hello, What are the characteristics of the betterry? Size, volt, ampere... Thank you so much

[@JamesBiggar]

Mentioned at the beginning of the video. You should watch it. It'll help you as much as it'll help me 👍

[@a-aron2276]

I would reduce the max charge voltage to 4.15v-4.17v you get way more life out of it. You'll sacrifice some range but not much.

[@dimitris000bourgos]

better for scooter batteries are 18650 or pouch cell of ncm?

[@rickrandom716]

Hi James! what are the dimension of the battery that would give me an idea on what to build for my bike. Thanks for the video

[@JamesBiggar]

As they are in the video, each of the modules that I built measure 10" wide, 14.75" high (not including the terminal posts), and 3.25" deep.

[@rickrandom716]

@JamesBiggar thanks! for some weird reason. I just got notified of your answer, and it has been over a month weird yt shadow ban

[@carpfun4789]

Amazing build , can you share the stl file for the top where are the pos/neg terminals , will be very thankful ❤

[@tylorbray]

Where did you buy your nickel strips?

[@Codyhumburg]

What adhesive do you use for the ABS cell holders? I use permatex ABS weld but the fumes are the worst.

[@jesseservice7828]

Muito bom !

[@dr.projectx5142]

Got a link to the spot welder you used for spot welding battery cells??.

[@JamesBiggar]

Links in the description of this video: kzbin.info/www/bejne/hGSwqZdvaZZ5itk

[@nothingbutthisthatandtheother]

Cool! Have you thought of having a mi battery slung under and a second battery using the Petrol tank filled with batteries as well? That's what I did on my 1964 Lambretta Conversion. I get a solid 720 km per charge

[@dailyrider2975]

Instead of heat gun can you use a electric iron to soften tape/glue to remove back easier?

[@JamesBiggar]

Use a towel or something between the iron and the plastic so the plastic doesn't melt and it should help, just be careful not to short it out, and make sure there's no water in the iron.

[@Dus306]

4:23 James, what would you consider a fire proof container to keep near by? Thanks

[@dansacco1964]

Nice work. Any idea what current the original bus bars in that pack are capable of?

[@JamesBiggar]

The nickel strips and BMS were only rated for 30-40A. I wouldn't count on the bus bars handling much more than that.

[@dansacco1964]

@@JamesBiggar Thanks. I've been eyeballing these packs for weeks hoping 2 of them would make a great cheap 20s moto pack without much work. Figured the BMS would have to go but I was unsure about the nickel. They are still an amazing deal but no shortage of work involved.

[@aissa-omar]

❤

[@johnmurphy5883]

Why did u say the original nickel wasn’t capable of the full current output of the cells? At the terminals it gets thin as it comes to a single tab but going between the cell groups there’s a lot of nickel. I have three of these packs and want to put out the max current. Depending where I look I’ve seen them putting out maybe 250amps and I planned to see my esc to that limit. I plan to dremel off the plastic at the terminals and solder a copper strip there and call it done.

[@JamesBiggar]

Being able to output 250A doesn't mean they should be. The cells in each pack can't even handle that kind of continuous current without risking serious damage, especially with the factory bus bars oriented as they are. The M50lt's are only rated for 14A continuous, 20A peak. 14 * 11 cells in parallel = 154A. At 72V nom, that's only ~11 kW. My bike motor can do 12 kW continuous, hence part of the reason why I broke down 3 modules and paralleled 5 more cells together in each string so the larger pack can handle at least 220A. Refer to the cell spec sheet and bare in mind that max power is not sustained power. But this is just the cells. One of a few reasons why a battery built for low load demands needs to be rebuilt to handle high loads. If you consult a nickel strip ampacity chart and do a calculation on the cross-sectional area, the factory nickel can't handle that kind of current without serious risk of a fire, either. More heat also means less efficiency. Heat is energy, and the more energy wasted creating it, the less you have to play with. Electric powertrains should be kept

[@PrincessUnicornSprinkles]

77AH in that form factor, energy density wise. is like. eek.

[@JamesBiggar]

Oh? Do explain. I might learn something.

[@XXHellBig125XX]

what are the mesurment on those 2 battery pack ?

[@mikemazzoli1990]

NICE build! I just got one of them packs on eBay and also building a battery for a smaller motorcycle 72v i was just going to use all the cells in the one pack how much did you get that affordable DALLY bms for? I'm now considering buying a second pack lol

[@gaswood5861]

$600

[@aaron092000]

600 no no, aliexpress will cost you $130 for the one in this video, but there is even more affordable ones on there, just be careful when choosing

[@Hambonebodi]

Prying around on a live battery with a screwdriver 🪛 to salvage the cells sounds like fun , i will have to try it sometime after i have built a battery or two , ❤ great job 👍,

[@Todd_G_FPV]

Look at all those headaay cells! What are u building with those?

[@JamesBiggar]

Golf cart for my grandfather. Too heavy, too little energy for high performance machines.

[@Todd_G_FPV]

@@JamesBiggar I just got a superbeast pack and turned it into a 12v 96ah for a solar generator I'm building!

[@patrickharrison5319]

Can we get an update on your buggy build? I'm sure others are interested in how all the parts have aged. Me, I'm curious if you've seen any decreased capacity on your battery. How many cycles would you guess it's gone through so far? Hopefully you haven't seen any decreased capacity, but still curious, as I used the same 32650s on my e-moto and I'd love to compare the age.

[@JamesBiggar]

It's been parked since last November, no place to drive it in the winter other than my driveway. The battery has only been cycled a few times, but in the 6 months it's been sitting in the cold, there's only been a 0.9% voltage drop. So that's a good sign at least. We just bought a couple of fields this spring so I've got lots of ground to tear around on now when I get a chance to revisit the project. I want to upgrade the suspension to make it a bit stiffer and raise it a few more inches so I can still hit the trails and maybe some jumps without bottoming out, though. I was planning on taking it for rip next weekend if I get caught up on work. We'll see. But we're definitely not done with it. Expect to see more at some point.

[@JamesBiggar]

Correction, my multimeter wasn't working properly. There's only been a 0.002% voltage drop over the winter. Had it out for a quick drive today. Still working fine :)

[@Roger7137]

Congrats. What do you do with all trash from this job?

[@JamesBiggar]

The tape and old nickel plates? Tape goes in the trash bin, nickel goes in my scrap metal bin. Everything else is reused or saved for future projects.

[@Appri]

How important would the bus bar trick(for current) be on a 18s5p pack, which is just two 9s 5p packs connected in series? Thank you so much! I was currently drawing current from the middle of the 5p groups, to try and maximize cell use.

[@JamesBiggar]

I wouldn't be worried about it with 5P, especially if you're pulling current from the middle of the pack and the load is equal to or lower than the max continuous rating for the cells. The original modules that I used were suitable as they were because the load from the bots wouldn't have overloaded the top cells. They just would've degraded faster than the others over time. But the top cells would have been overloaded in my bike for sure, which necessitated the switch.

[@Appri]

​@@JamesBiggar Thanks for the great information! I'm planning to build another 20S 12P pack for my main scooter (the 18s5p is for a friend), and ill be pulling a lot of current, hopefully it doesn't go too crazy then. I'll definitely consider the whole bus bar option for that. I'm using samsung 50S 21700 cells and pulling a max of 20A from each cell (they are rated for 25A but higher if cooled), for not a long duration.

[@Appri]

​@@JamesBiggar I have a big concern. In the 20S 12P pack, i only have 10 cells horizontal space. This means I'll have to connect two 10s12p packs in series. For a 12P pack, when i connect it in series, if I just use a singe long copper plate it'll definitely cause some major issues as current would prioritize the few cells that are closest together. should I solder on some thick gauge wires to the + of the first 10s12p, and - of the second 10s12p, then join them together that way to mitigate this problem?

[@sumuditha6602]

✌️

[@carlosdominicodiaz656]

Quiero una así para mi moto

[@rendi6750]

Setelah 5 bulan menunggu eps 3,baru rilis😢,proses lama dan panjang

[@JamesBiggar]

....and a lot of $ in a time when we're all struggling and have bills to pay. These projects aren't cheap or easy to create, hence the timeline. Especially after buying two batteries for this one. If it were a manufacturer that was prototyping this bike from scratch as I am, then it would be a 2-3 year process, not 5 months. And they'd have millions of $ at their disposal to do it. Thanks for sticking around, but budget determines everything and I'm just one guy. I can only spend so much at a time ✌️

[@rendi6750]

@@JamesBiggar iya terimakasih sudah merespon❤saya akan slalu menunggu setiap perkembanganya,benar itu pasti menghabiskan uang yang banyak juga dan proses yang panjang,semangat saya akan mengsupport dengan terus menonton video anda,terimakasih

[@philipmillwood526]

Any estimate on how much current the included nickel will handle? Ive got a couple of these and planned to replace the BMS only.

[@JamesBiggar]

I wouldn't pull more than 40 or 50A through it. I haven't measured its exact thickness, but I know it's no more than 0.2-0.3mm between the cells, and the main bus bars 'might' be 1mm, and I don't think they're pure nickel or copper (or nickel plated copper). They're very stiff, not soft like nickel or copper. They could be nickel plated steel. You'll want to double check and measure their thickness because that will tell you what the pack can handle - the bus bars would've been built for the current the pack was built for. A 1mmx10mm pure copper strip can handle 49A. Bare in mind that the og modules are built so that the top cells in each series string are taking most if not all of the load vs spreading the load with the reversed bus bar configuration that I used, so they're at a lot more risk of being damaged from overcurrent and are going to degrade sooner than the rest. Each M50 LT cell can only handle 10A continuous and 20A peak, and being in a series connection together, the top cells will each bare the full load, not together. Ie: if you want to pull 50A from the pack, then you're probably going to pull close to 50A through each cell between each series connection at the top. With the arrangement that I used, that 50A load would be spread out to almost every cell in every string so that each only has to deliver a fraction of that current because it's forced to flow from top to bottom through all of the parallel connections to enter and exit the pack instead of just flowing across the top through the series connections. I would personally rearrange the bus bars so the pack lasts longer, but I think if you keep the load under 40-50A then they'll probably be fine as they are. The original bms can't handle anymore than that, so the conductors likely won't either, and I definitely wouldn't push the cells beyond that without making some changes. Use the ampacity chart here for reference: evolveforums.com/attachments/ampacity-20-10-20meter-20-20low-20temp-jpg.2903/

[@philipmillwood526]

@@JamesBiggar awesome! Thanks much for your input!

[@yusefkee9091]

Do you build batteries for people, what’s cost

[@beinghappy1312]

Any reason why you didn't solder the wires directly to the bus bar?

[@JamesBiggar]

Takes a lot of heat to get that bus bar hot enough to tin and solder properly. More than my iron and patience can provide, anyway.

[@diyelectrified1289]

@12:20. Did you consider soldering the lugs on rather than drilling and tapping with epoxy? That's how I would have done it otherwise I always like your approach

[@JamesBiggar]

This is a decades old debate that no one will ever win. I try not to use solder when it's not required, especially on lugs. The connection as it is is superior to a solder joint in terms of conductivity, since solder itself has a higher resistance than copper and any used to connect a lug to the bar would increase the resistance in that connection just as it did when I soldered the copper wire to the nickel. Not a lot, but if it doesn't need to happen then there's no sense doing it imo. Those screws and epoxy kill two birds with one stone, the same as solder, without increasing resistance.

[@JamesBiggar]

...also, a 1/8x3/4" copper bar would take a lot more heat to solder to properly than what my 100w iron can provide.

[@diyelectrified1289]

I have to disagree with the conductivity part. A mechanical connection when looked at under a microscope makes very small connections due to surface linearity not being perfect. Solder is not a perfect conductor, but because of the sheer volume and the way it alloys itself to the metals that it solders too creates a higher conductive connection than a mechanical connection. There's nothing stopping you from putting some solder paste underneath your lug and mechanically torquing it down the way you did and then applying a little bit of heat. I usually use 150 watt to 200 watt soldering iron for connections to thick copper like that with no issues.

[@JamesBiggar]

I'd have to disagree on that one. If solder were superior, then every permanent electrical connection would be soldered. Torque is important for mechanical connections, whether we're talking about mashing a lug into a soft copper bar or mashing strands of wire into a solid mass with a crimp. Don't torque it properly, then it's not done properly. From my experience, I've always measured higher resistance from soldered joints vs mechanical. But again, it's a decades old debate that no one will win unless you want to provide some data from the results of said microscope analysis on a properly torqued connection vs solder. Perhaps my soldering skills aren't as good as I thought? It's possible. I'm easy to sway with hard facts if anyone has them ;) Each has pro's and cons and we could argue about anecdotes all night. I think mechanical is better, but drilling and threading like this takes time. Pick your poison my friend.

[@diyelectrified1289]

I hope it didn't sound like I was trying to debate you because that was not my intention. I'm a circuit board guy with 30 something odd years of experience in consumer and industrial electronics so soldering is my gig. Now that we started down this road I think at least for myself I have to figure out which is better. So I think I'm going to grab that micro ohm meter we have at work and do some testing. Cheers

[@V4suki]

I am only on ewho puts resistors on bms leads to even out resistance? I mean it's cheap way to make bms see batteries correctly, you can buy 1000 resistor pack for like 5 dollars.

[@JamesBiggar]

From what I understand, you are. A BMS should already monitor the battery correctly through the balance wires, not the negative power lead - that's just a transmission cable. I would assume that if an extra resistor was required to work properly, then they would have built it into the lead or included it separately...would they not? Kind of strange to be in business for so long selling a defective product that's become really popular otherwise, wouldn't it be?

[@ahaveland]

*Never put resistors on BMS sense leads* - they have no effect on sense voltage if there's no load, and as they are used for balancing, they have to carry some current without dropping voltage, wasting heat and ruining balancing capability. Why would anyone do such a thing?

[@JamesBiggar]

Thank you! It didn't make sense to me, but I'm no engineer.

[@DeveloperOwner-q3l]

if you well sell this how much would you sell it?

[@berislavtopol1404]

I do not see the point doubling nickel strip for parallel conections between cells. Please explain?

[@JamesBiggar]

Already did in the video.

[@NoHandleToSpeakOf]

Just bus bars and no fuses?

[@JamesBiggar]

Nope. If I had put any more in parallel then I would have considered cell fusing. But the old packs didn't have them with 10P and they're LG cells, not generic no names from who knows where, so I'm not too concerned about it.

[@m1llie_]

Do you know if there's a specific reason that these batteries use a rectangular packing of the cylindrical cells instead of a more space-efficient triangular packing?

[@JamesBiggar]

Triangular? Not sure what the benefit of trying to pack a triangular battery into a rectangular robot would be. Triangular batteries fit better in triangular spaces. If you mean a staggered cell spacing in the battery to pack them tighter, then there's also a good reason that isn't usually done either. Packing cells too tight causes more heat buildup and lower performance efficiency. Some cell chemistry doesn't produce a lot of heat and others do. This is the type that does. The space gained by staggering cells is marginal compared to the gains in performance efficiency. The space available in the bike can accommodate a battery 3X this size, if I had a budget to build one. So space isn't an issue in this case.

[@m1llie_]

@@JamesBiggar thanks for the reply, I was referring to the cell staggering. Hadn't thought about heat dissipation

[@ahaveland]

@@m1llie_ It's called "hexagonal packing", though it can make triangles!

[@theblackbike9083]

Thats a very big bms, why didnt you buy a Ant BMS?

[@JamesBiggar]

Besides the obvious fact that an Ant doesn't have built in forced air cooling to counter their fallacious current ratings, which would make them larger like this Daly? Because I don't trust companies that don't rate their gear properly because they want to give the impression it's more powerful than it actually is. A 250A Daly is rated for 250A continuous and 400A peak, as advertised. A 250A Ant bms is rated for 250A peak, not 250A continuous like it should be. Understanding how much surge power a device can handle is helpful for design, but in reality no device works under surge power constantly because conductors and components can't sustain surge power for very long. A few seconds at best. That's why electrical components are rated in continuous current because that would be the normal operating condition. Any device pushing peak for too long is doomed to fail, so rating devices on it without explaining the difference to the avg DIY'er is stupid at best, dishonest at worst. Early marketing didn't clarify that with Ant - you were left to guess until push back from consumers and regulators forced them to start posting continuous current rating. When a company is intentionally vague to artificially inflate ratings in the consumer's minds, that's a giant red flag for me. Especially when they're claiming peak values that are twice what their competition's is, from bms' that are smaller than their competition. It doesn't add up unless they're using space age material with different properties than standard conductors that only they have access to. Which I highly doubt. I don't want to deal with a company like that.

[@chuyskywlk]

You're just gonna not say anything about the dozens and dozens of headway cells in the background there, eh? ;D

[@JamesBiggar]

Lol, future ev project. Something more laid back than a street bike.

[@reynaik4381]

Can you please explain me in simple terms how much Kwh is the battery pack ?

[@JamesBiggar]

V*AH=WH

[@tjuanwashington4359]

Why don't they make them like a battery charger but bigger and not welding it together I like my way like you using it in a battery charger but bigger one

[@JamesBiggar]

Lol, ok...

[@idiatools]

Hello sir