DIY assembly kit for 18650 without spot welding/Soldering

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banjaxxed
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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by banjaxxed » Jun 23, 2017 12:18 pm

Thanks for that info
mlt34 wrote:
banjaxxed wrote:Question to those in the know is using nickel to interconnect the parallel pack ok?
Yes, for the parallels you can use a surprisingly small connector, even thin wire would work. There is very little current flowing through the parallel connections. All the cells drain basically equally, so the only current that flows sideways (between parallel cells) as opposed to forwards and backwards (charging and discharging via series connections) is a small amount of balancing current.

If your balance wires are only connected in one spot on the parallel group, as they almost always are, then the parallel connection only needs to be sufficiently strong to carry the balance current, usually not more than like 0.2 amps.

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by Matador » Jun 23, 2017 12:19 pm

I just realised... indeed nickel strip is more than enough to connect the cells in one same parrallel group... so no real need for copper bussbars here (unless its a the 2 battery terminals end)... and since all series cells have there own silver plated wire connection you are golden. I could actually make mini copper bussbars for series interconnections.... i've done it in the past. I've even nickel plated some copper bussbars made of flattened pipe with homemade nickel acetate. The result wa shiny :
IMG_0449.JPG
https://endless-sphere.com/forums/viewt ... 5#p1235640

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by banjaxxed » Jun 24, 2017 4:01 am

One of those home nickel plating kits huh? [THUMBS UP SIGN]

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by mlt34 » Jun 24, 2017 8:28 am

Oooh I've been wanting to try some nickel plating in the kitchen. I watched some youtube videos and was tickled at how simple it looked :D
Are you planning your first electric bicycle conversion? I wrote a book that teaches beginners everything they need to know about building their own ebike.
Then I wrote the book (literally) on building custom lithium batteries.
I also write for EbikeSchool.com, a site that does mainly how-to style articles and other informational write-ups. Check out our youtube channel for great how-to battery building videos.
Lastly, I run www.Vruzend.com, which sells solderless 18650 battery kits, 18650 cells, li-ion chargers, BMSs and more!

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by Dumsterdave » Jun 24, 2017 8:59 am

looking to build a battery using this kit. I have a box measuring 450mm x 95mm x 120mm. The vruzend site, a single cell would measure 22mm x 88mm. According to my calculations, i can fit a total of 100 cells in this box not including the BMS. Im thinking id like to build a 14s7p battery (which would come out to 84 cells and take up 110mm x 374mm) This is if i place the blocks 5 rows and 17 columns (or 5 columns and 17 rows). i dont know the measurements of the BMS, but im assuming i can fit it?
Now, this is where i need help.... How do i design the pack? if i were doing a 14s5p then i woldnt need to ask, but id like to use as much of the space i can. Since i can't just create 17 rows of 5p, i need to figure out a way to connect the cells in series.

i have no battery building experience so any help you guys/gals can give would be greatly appreciated

oh and id like to be running 30A controller, which would put each cell at about 4.3A.... Is that ok? or a bit high?

Dave

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Matador
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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by Matador » Jun 24, 2017 9:29 am

banjaxxed wrote:One of those home nickel plating kits huh? [THUMBS UP SIGN]
LOL. A completely artisanal home kit...

HERE'S MY KITCHEN RECIPY FOR THE NICKEL PLATING OF BUSSBARS (Note : Please wear gloves, as the nickel acetate we will make is a known carcinogenic).

Canadian nickel coins dating between certains years are 99.99 % nickel metal (information on purity by years available on wikipedia) and can be used (while less pure coins would be unsuited).
I didn't even had to buy nickel metal since I had some that was pure enough in a coin pot at my house.

Then I concentrated some white distilled vinagar (5% acetic acid) by slowly heating it on the stove with the Bain Marie technique... Since water boils at 100°C and vinegar will not evaporate as easily as water (pure acetic acid boils at 118°C).
I let the water slowly evaporate over hours until I got half of the initial volume in liquid (twice more concentrater) : So I ended up with 10% acetic acid (chemistry goes faster is you use more concentrated reagents). So in a way, I sorta made acetic acid moonshine... (but you throw away the water that evaporates and keep what's left in the still intread of throwing it away).

Then, I took 2 nicklel coins and 2 cables, and solder one coin to one wire (this part is tricky... wou want the less solder as possible to not contaminate the solution once you place the electrode in it). Repeat for many electrodes
So there you go 2 electrodes made (The nickel coin electrodes)..

To make nickel acetate, I just dipped 2 nickel coin electrodes in the vinegar moonshine and let current run through for 2 days or so (solution gets quite hot... which speeds up the chemical reaction even more). Once judging by the color which don't get stronger, I decide that the solution is saturated enough in nickel acetate.... I stop the current throught the electrodes. Then I filtered the solution on a coffee filter (Do Not drink it !!!)

Pour in a safe (air tight.... oxidation will cause sublte precipitate with time) airtight container until your ready to plate some copper. See the numerous you tube tutorials.

To plate, one eletrode is a nickel coin and the other one is the copper piece.
You will have to experiment to find the sweet spot.
In general, the longer the plating takes (ex : lower current, bigger surface area of piece, bigger diatance between copper and nickel coin eletrodes, temperature of Ni(OAc)2 solution, volume of solution used for plating), the better the plating result. Plate too quick and the nickel layer will flake off. MY plating is awesome... I've use my plated copper bussbars a few times now, overtightening brass bolts and nuts on them many times. NO FLAKING.... Plating just doenst move.

For making the solution, you can use a powersupply (get some good amps), but for plating your copper piece, use DC current WITH NO RIPPLE... The best is to use a battery as the electric source for plating. I used some 18650 (4 or 5 in parallel if I recall well). Voltage ripple gives bad plating results). I think IIRC I had added a very very very small amount of salt (NaCl) to speed up making the Ni(OAc)2 solution but you want the least possible amount as a less purity means not as good plating rewsults afterwards. I think I also added a small bit of hydrogen peroxide (aside from diluting the solution a bit.... H2O2 in not an impurity as it's basically water and oxygen... it justs redilutes you precious Ni(OAc)2 solution).

On think, I did use Silvo Polish to reveal the nice nickel plating mirror finish... Felt like I was a swordsmaster, polishing a katana blade I made :wink:

Read my other post where I show picture of nickel plating process : https://endless-sphere.com/forums/viewt ... 5#p1235640

Time consuming, but oh so worth it. It's been a while now... I got NO tarnish. Bare copper would be dark brown way before that time.

Matador
Last edited by Matador on Jun 24, 2017 9:43 am, edited 7 times in total.

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by mlt34 » Jun 24, 2017 9:29 am

4.3A continuous will start to have some heat build up in the contacts, but I imagine you won't be running continuous all the time (most level riding is well below full power, plus factoring in stops and starts, etc).

As far as laying out the battery, you'll follow the same idea as if you had 14 columns, but you'll have to start "wrapping around columns", if that makes sense. So the first column would be 5 cells in a parallel group, but the second column would have 2 cells from that first parallel group and then the first 3 cells of the second parallel group. You'd have 3 cells there that could perform the series connection, instead of 7 which would be ideal. So you'd want to reinforce those series connections with multiple busbars or even short lengths of wire, to give more current pathway for the electrons.

At risk of sounding like a salesman, I did write a book on building lithium batteries that you might find helpful. The link is in my signature below.
Are you planning your first electric bicycle conversion? I wrote a book that teaches beginners everything they need to know about building their own ebike.
Then I wrote the book (literally) on building custom lithium batteries.
I also write for EbikeSchool.com, a site that does mainly how-to style articles and other informational write-ups. Check out our youtube channel for great how-to battery building videos.
Lastly, I run www.Vruzend.com, which sells solderless 18650 battery kits, 18650 cells, li-ion chargers, BMSs and more!

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by Matador » Jun 24, 2017 11:25 am

Okay, So I performed a third cycle on my Vruzend Old laptop cells 14S8P battery.
I perfected the case, added a shunt, a watt-meter.

Distance : 31 km
Watt-hours used on the 30A BBSHD : 403 Wh --> This is 13 Wh/km (but there's massive voltage drop so I'm more in the 900-1300 W with full WOT than what I should be getting 1400-1700 W). Still manage to reach 56 km/h WOT+Peddling

I have to say, I get massive voltage sag.... Pulling full throttle, watt-meters shows 25A peak (rather than 30A) and volt go from 51V to 41V. (When I checked for that, battery was already hot and around 50% SOC).
So yeah 10V drop with 25A load on these old laptop cells.... Meaning even though cells were initially calculated to give 250 mOhms, after 3 cycles, the really reading (inside the Vruzend SS Kit) is actually more around 400 mOhms... I'm pretty sure it has more to do with 18650's deterioration... I mean 69°C can't be too good on 10 years old laptop cells getting flogged a 1.5C.

Pics :
Batt.jpg
Batt2.jpg
Watt-hrs.jpg
Temps.jpg
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Matador
Last edited by Matador on Jun 24, 2017 1:58 pm, edited 1 time in total.

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by mlt34 » Jun 24, 2017 1:49 pm

Yea those laptop cells are definitely going to be taking a beating. 1.5C is basically the limit for even some name brand cells like Samsung 26F and Panasonic 18650B cells. So those laptops cells are probably being pushed past their realistic design limits. But hey, it's for science, right?! :lol:
Are you planning your first electric bicycle conversion? I wrote a book that teaches beginners everything they need to know about building their own ebike.
Then I wrote the book (literally) on building custom lithium batteries.
I also write for EbikeSchool.com, a site that does mainly how-to style articles and other informational write-ups. Check out our youtube channel for great how-to battery building videos.
Lastly, I run www.Vruzend.com, which sells solderless 18650 battery kits, 18650 cells, li-ion chargers, BMSs and more!

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by Matador » Jun 24, 2017 1:57 pm

mlt34 wrote:Yea those laptop cells are definitely going to be taking a beating. 1.5C is basically the limit for even some name brand cells like Samsung 26F and Panasonic 18650B cells. So those laptops cells are probably being pushed past their realistic design limits. But hey, it's for science, right?! :lol:
LOL Yeah....
Honestly, I think it was time tfor someone to show some figures about the deterioration of Old laptop 18650 not being suited at all for eBike (at least not a 30A BBSHD on a 14S8P batt). People asking themselves that question can now relate to these numbers and move one to quality cells and not waste time on scavenged laptop cells... Or they can either use a small 10A controller or go very big with high P number (I'd go with 15-20P for the BBSHD).

For people needing real numbers, see my Excel File.... Before and After : How each laptop cell's capacity is affected by 200 km of eBiking :
Before :
Li-Ion.xlsx
(2.4 MiB) Downloaded 34 times
After :
Laptop Li-Ion (v2).xlsx
(2.29 MiB) Downloaded 28 times
Out of curiosity... compare my laptop's cell DCIR to the ones I got from Doctorbass VTC4 :
Makita VTC4 cells from doctorbass.xlsx
(518.4 KiB) Downloaded 37 times
HuUGE difference ! We're talking 6 times less resistance (I recently dicovered that the Imax B6 INTERNAL RESISTANCE function is surprizingly close to reality for DCIR measures.... in the 20-25 milliohm range, accuracy is around ±5 milliohm... not bad for a two lead meter).

For the laptop cells, either I'll just kill them by abusing them, or I should just stop right there and recycle them for some sort of small camping powerwall or some powerbank... Donno, I'm charging them again at the moment :D
I still have some 286 Sony VTC4 cells lying around that I should put to good use. 30A cells.

Hopefull 1.5C doesn't put to much stain on VTC4... Anyways, I enjoyed building these batteries and battery cases

Anyways people, forget Old scavendged laptop cells... No good.

Matador

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by mlt34 » Jun 25, 2017 2:52 am

It's a shame to do all that work only to break everything down again, but if it were me, I'd save the laptop cells for a low power project. They are still "good" in that they hold charge and can deliver low power, so a camping battery or a mobile charging bank for a cell phone would be a great use for them. And they'll certainly last longer than if you work them to death on your ebike.

The Sony cells are almost the opposite extreme. Those things can do 30A per cell, but the vruzend kit can't handle 30A per cell through its contacts, so it's almost a waste on the opposite extreme, haha. I mean, they'll definitely work well in the vruzend kit, but it won't let them reach their full potential. Like putting a restrictor plate on a carburetor.
Are you planning your first electric bicycle conversion? I wrote a book that teaches beginners everything they need to know about building their own ebike.
Then I wrote the book (literally) on building custom lithium batteries.
I also write for EbikeSchool.com, a site that does mainly how-to style articles and other informational write-ups. Check out our youtube channel for great how-to battery building videos.
Lastly, I run www.Vruzend.com, which sells solderless 18650 battery kits, 18650 cells, li-ion chargers, BMSs and more!

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by Matador » Jun 25, 2017 3:00 am

mlt34 wrote:It's a shame to do all that work only to break everything down again, but if it were me, I'd save the laptop cells for a low power project. They are still "good" in that they hold charge and can deliver low power, so a camping battery or a mobile charging bank for a cell phone would be a great use for them. And they'll certainly last longer than if you work them to death on your ebike.

The Sony cells are almost the opposite extreme. Those things can do 30A per cell, but the vruzend kit can't handle 30A per cell through its contacts, so it's almost a waste on the opposite extreme, haha. I mean, they'll definitely work well in the vruzend kit, but it won't let them reach their full potential. Like putting a restrictor plate on a carburetor.
Yes, The Vruzend v1.0 SS, is probably best suited with cells like the PF, the GA, etc (10A drain cells).
I might choose to solder or spotweld my VTC4 cells.

But the beauty of the Vruzend kit is that I can always reuse the parts if I change my pack. I'd really want to see a v2.0 Vruzend.
Hopefully Vruzend is getting closer to pay the cost of the inital RnD they've invested... and starting to make lots of profits.
In that way, they could afford to start working on the Vruzend 2.0 kits

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by Sushichefva » Jun 28, 2017 3:11 am

Waiting on version 2 to purchase. Looking great.

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by rumme » Jun 29, 2017 10:01 am

I don't know if this has been mentioned. After watching some videos of assembly with these packs, it seems like the batteries fit very snug inside the holders, to the point of having to use a mallet to bang both sides together and get a snug fit all the way around. I would imagine when it comes time to disassemble them , to repair 1 or more cells, it could be a hassle, with such a snug fit, and also the pack being compacted for a year or more on the ebike.

Maybe, a better idea is to make each battery/cell holder about 1m.m larger in circumference, so the batteries still fit nicely but not to the point that the 2 halves have to have a mallet used to compress them ...instead, have 4 or more clamps that can be flipped down to tighten the pack...kinda like the clamps on a briefcase...there would be 1 clamp on each side on the outside of the plastic casings. When a battery needs to be replaced, just unhook the clamps and the pack easily disassembles.

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by parabellum » Jun 29, 2017 11:09 am

rumme wrote:Maybe, a better idea is to make each battery/cell holder about 1m.m larger in circumference
No, they are fine, it is easy enough no pry them apart.
Actually you do not need to pry apart whole pack for repairs, if you orient the dovetails of the holders right way, you can split the pack in any place and remove the Series block or cell with the holder mounted.

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by mlt34 » Jun 30, 2017 4:57 am

parabellum wrote:No, they are fine, it is easy enough no pry them apart.
Actually you do not need to pry apart whole pack for repairs, if you orient the dovetails of the holders right way, you can split the pack in any place and remove the Series block or cell with the holder mounted.
Truth.

Also, the mallet method was part of the earlier instructions with the prototype kits, because when you try to compress many dozens of cells at once into the caps, the snug fit adds a lot of resistance. The improved method has you assembling just one column at a time (usually 3-7 cells). This way, it is easy enough to do it either by hand or with a squeeze clamp. No hammer needed and you get parallel groups that you join together sort of like the normal method of battery building with spot welded parallel groups.
Are you planning your first electric bicycle conversion? I wrote a book that teaches beginners everything they need to know about building their own ebike.
Then I wrote the book (literally) on building custom lithium batteries.
I also write for EbikeSchool.com, a site that does mainly how-to style articles and other informational write-ups. Check out our youtube channel for great how-to battery building videos.
Lastly, I run www.Vruzend.com, which sells solderless 18650 battery kits, 18650 cells, li-ion chargers, BMSs and more!

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by 999zip999 » Jun 30, 2017 11:24 am

Matador with all the time and learning you put in to those cells. Mapping capacity and matching it could last a long time if used reasonably in it's limits. Or use it to haul your heavy ass up a steep hill for two months. Let's give those sony cells a try. Should have long life at 30amp with middrive.

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by eyebyesickle » Jul 15, 2017 12:32 am

Cool, it worked.

Now I will get the rest sorted...

I tried to make the method obvious...

Just keep it under 4a a string, people!

Perfect for stealth bicycle conversions!

Thanks again
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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by mlt34 » Jul 15, 2017 4:17 am

I love a good jig! That's a creative way to do it. Nice job!
Are you planning your first electric bicycle conversion? I wrote a book that teaches beginners everything they need to know about building their own ebike.
Then I wrote the book (literally) on building custom lithium batteries.
I also write for EbikeSchool.com, a site that does mainly how-to style articles and other informational write-ups. Check out our youtube channel for great how-to battery building videos.
Lastly, I run www.Vruzend.com, which sells solderless 18650 battery kits, 18650 cells, li-ion chargers, BMSs and more!

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by ElectricSushiChef » Jul 15, 2017 8:17 am

So when is Version 2 coming? I thought July. I'm impatient my apologies.

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by ElectricSushiChef » Jul 15, 2017 8:20 am

You know after watching the bms install video on YouTube.... I noticed there is still 7 or so things you must solder. Guess I need to learn to solder.

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by mlt34 » Jul 15, 2017 9:55 am

ElectricSushiChef wrote:So when is Version 2 coming? I thought July. I'm impatient my apologies.
We haven't announced a release date yet since we're still working on the design and testing phase. Then we'll have to make some production changes since we won't be able to use the same production line. It's likely that we'll have it out by the end of the year, but we don't have a firm date yet.
Are you planning your first electric bicycle conversion? I wrote a book that teaches beginners everything they need to know about building their own ebike.
Then I wrote the book (literally) on building custom lithium batteries.
I also write for EbikeSchool.com, a site that does mainly how-to style articles and other informational write-ups. Check out our youtube channel for great how-to battery building videos.
Lastly, I run www.Vruzend.com, which sells solderless 18650 battery kits, 18650 cells, li-ion chargers, BMSs and more!

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by banjaxxed » Jul 16, 2017 3:29 pm

That's a good point the bus bars could have pre-drilled holes for logs to be attached to balance wires...or learn some basic soldering [THUMBS UP SIGN]
ElectricSushiChef wrote:You know after watching the bms install video on YouTube.... I noticed there is still 7 or so things you must solder. Guess I need to learn to solder.

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by tomjasz » Jul 23, 2017 4:17 pm

mlt34 wrote:
ElectricSushiChef wrote:So when is Version 2 coming? I thought July. I'm impatient my apologies.
We haven't announced a release date yet since we're still working on the design and testing phase. Then we'll have to make some production changes since we won't be able to use the same production line. It's likely that we'll have it out by the end of the year, but we don't have a firm date yet.

Current design works just fine. No reason to wait, given the low cost.
Thanks Justin_le we're here thanks to you. All the best to the mods for their tireless work keeping it on an even keel.

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Re: DIY assembly kit for 18650 without spot welding/Solderin

Post by coolbobjoe » Aug 01, 2017 10:25 am

v2 orderer ready to send payment ;)

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