yet another solderless DIY battery pack via NIB's

Quick update on my nib pack.
I had one cell fully disconnect in 4P formation from its 3 friends.
This P was one of the nickle strips that was direct nickel on terminal attachment with nib on top (positive side).
The otherside (negative side) of this P4 setup was the thin copper foil and they were all connecting fine..
It was the second middle cell that disconnected and the nib on top was perfectly on top, it seems like the nickel strip just bent a bit maybe from a big bump and there just wasn't enough pull to keep it connected to the battery, or the whole battery pack shifted inside the plastic battery ebike case which to make matters more difficult is inconsistently shaped/molded on the inside.

So there you go, besides nickel being in theory the best metal due to low electrical resistance and high resistance to corrosion it has arguably been the first to failure due to its stiffness in my pack, but this is still just a guessing conclusion.
I think if you build carefully any of these metals and methods will work.

I have gone back to the more original design and placed a nib directly on the cell contact first and then a nib on top (nickel strip in between) . Will see how it goes over time.
Maybe this can be fixed if I can find even thinner nickel or some kind of super thin nickle wire braid type might be a good way to go.

Just trying to find what the options that are out there that I might chuck on a P to see how it goes,, nickel or silver plated copper braid would be something cool to try...
http://www.coonerwire.com/braided-wire/
 
Came across these on fasttech, wondering if they could be used in a nib pack... like place a nib ontop of each one or something.
there are a bunch of different shapes and sizes on the ft site.
http://www.fasttech.com/products/1425/10012817/2157800-stainless-steel-flat-top-cover-cap-for-18650

Also gaskets
http://www.fasttech.com/products/1425/10012815/2157501

Also Insulating Seal Ring
https://www.fasttech.com/products/1425/10012816/2157700
More about these here
http://www.endless-sphere.com/forums/viewtopic.php?f=8&t=65971#p1013373
 

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Just a small update on my nib ebike pack. I am using it around 3-4 times a week and its working just fine, no problems.
I am a bit surprised it has worked so well, being in the hard plastic case and mounted directly on the frame down tube it gets a fair amount of bumps while I ride but has managed to stay solid since my last post, visually its internals looks kind of ordinary quality build but so far the reliability/performance says its quality.

Also I got sick of the LR44 button batteries in my disc brake vibration alarm locks so when the batteries died in them I changed them over to 15266/15270/CR2 cells.
I guess this is just an expansion of where you can use nibs on lithium cells. Like detailed in my previous construction method posts here, I just took one sided adhesive copper tape and wrapped it around the nib with the battery terminal connector from the alarm lock circuit that normally fit in the LR44 cell battery housing.
IMAG0248.jpgIMAG0249.jpg
These managed to just fit them in after removing excess plastic guts and housing.
Replacing 3S2P LR44 button sells with a single lithium cell gives around the same voltage. The green cell shown here has a protection circuit as well.
So far both locks are performing great.

*Edit*
I decided to replace the first lock above with this mini pouch battery I also use to upgrade my Mobious sports camera with. I actually ordered the 520mah but they sent me the 820mah version, I think because they don't stock the 520mah any more.
http://www.banggood.com/Mobius-3_7V-820mAh-Upgraded-Battery-for-Action-Sport-Camera-p-956606.html

These ones are the smallest, they fit really well https://www.banggood.com/index.php?com=account&t=ordersDetail&ordersId=12622875
SKU181130-1.jpg
 
cwah said:
So you still need 2 magnet per connection to have it working correctly?
Nar I am currently using 1 nib per connection.
See in this photo above, I cut out a piece of nickle foil sheet and placed it over the 18650s with the nibs on top, I then left excess nickle sheeting length and rolled it over my main negative lead wire and crimped it down with my powerwerx anderson crimp tool (which has the extra die bolted off so its just a generic crimp tool now)
Also used some generic glue on the nibs and nickle sheet so it can stay together more easily and be removed in one piece more easily.
 
I've seen you removed the battery bracket. taking too much space?

Too bad you have to glue that out, as to remove it you have to heat it up (and demagnetise magnets?)
 
cwah said:
I've seen you removed the battery bracket. taking too much space?

Too bad you have to glue that out, as to remove it you have to heat it up (and demagnetise magnets?)
Yes I removed the 18650 cell holders because they took up too much space in the ebike case I bought and the cell holders also get in the way of the nickel sheet as access to the battery terminals isn't perfectly line of site straight, normally when tab welding them it would arch over the cell holders slightly but since its welded on it wouldn't be a problem but with nibs just holding down the nickel sheets any obstruction can adversely effect contact performance.
The glue I am using to secure the nibs on the nickel sheet is just a soft glue that peels off easily.

I was thinking it would be great to get one of these Android themal image cameras and look for heat on the build under load.
http://www.androidpolice.com/2014/09/25/hands-on-with-the-199-seek-thermal-smartphone-infrared-camera-yes-really-actually-this-is-amazing/
http://arstechnica.com/gadgets/2015/01/07/updated-flir-one-infrared-camera-is-smarter-smaller-works-with-android/

Anyone got one of these flir cameras and fees like building a nib pack? :mrgreen:
 

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Was thinking about the issue of how the 18650 cell holder brackets get in the way while my cat was trying to kind of push his nose through one of the holes in the 18650 cell holder bracket like he was trying to tell me something...

It then hit me why not just remove those pesky tabs and let the cell go all the way through? This way the nickel sheet isn't inhibited in anyway of making contact with the cell terminals..

So here is a pic so far where you can see all the cells poking right through, the tabs on the cell holder brackets do break off quite easily with long nice pliers..
IMG_20150712_124410.jpg

This new radical design technology I attribute from my cat. He gave me new ideas/direction... things I never would of thought of... all my battery pack work is based on it.
 
if you need anything 3d printed i got a buddy who has a portable home unit but it can only do stuff thats like 4 inchs by 4 inches
 
dnmun said:
the currents flowing in the parallel link are not measurable. the parallel link is there to allow the cans to balance to each other. the parallel link does not carry current.

the current is carried in the serial connection from one channel to the next in series. for that you need almost nothing for these little cans. at 2.7Ah then 4C is about 10A and it only takes an 18AWG wire to carry 10A.

the 1mmx4mm strip to connect the cans in series can carry up to 40A. if the connector is made so that it only contacts one edge of the case on the bottom then the amount of heat needed to reflow the solder could be kept minimal and the sponge would soak it up in a flash as soon as you hit it.

a soldered connection is more reliable and has the minimal contact resistance of all forms of connection.

Dnmun's words, not mine......
the current is carried in the serial connection from one channel to the next in series. for that you need almost nothing for these little cans. at 2.7Ah then 4C is about 10A and it only takes an 18AWG wire to carry 10A.

How much solder would be required to solder a 18awg (1.0237mm) wire to a cell? Not Much!
The soldering iron, wouldnt heat it up that much. The steel outside can is a heat sink right.

This magnet thing had me at first, I was intrigued, then I got to thinking about it....its crazy. Shorts etc.
 
Why did I not see this thread sooner? TheBeastie you have had a genius idea! I want to try this too :D

It is compact enough to go inside a bootplate and it looks solid enough withstand vibrations! Plus with glue like epoxy it will be a killer combo. BTW do you prefer copper or nickel for your packs? I think copper has way less IR?
 
Vanarian said:
Why did I not see this thread sooner? TheBeastie you have had a genius idea! I want to try this too :D

It is compact enough to go inside a bootplate and it looks solid enough withstand vibrations! Plus with glue like epoxy it will be a killer combo. BTW do you prefer copper or nickel for your packs? I think copper has way less IR?
Yeah I recommend copper foil, thin copper foil. Mainly because contour is very important and its more inhibiting factor then the potential corrosion issue you may get then using nickel in my opinion. Nickel is a lot more stiff which is a problem, I have not been able to find super thin nickel foil.
And yes copper has less resistance on top.

Forum member riba2233 has made a affordable and reliable spot-welder that a lot of members are using now so you might consider that path.
https://endless-sphere.com/forums/viewtopic.php?f=31&t=68865
But since I have played with this nib concept stuff for a while now I do actually find it fun and maybe in some ways it can be argued that I just enjoy doing things the odd geeky way.
 
Yes riba has an awesome spot welder but I just love the idea of having swappable cells with nothing else than fingers (and eventually a screwdriver) :p
 
Vanarian said:
Yes riba has an awesome spot welder but I just love the idea of having swappable cells with nothing else than fingers (and eventually a screwdriver) :p
Yeah I recommend copper foil with one side being adhesive, like how it is here... and you place the copper over the points and then place the nibs on the inside (adhesive side) and push it down over the cell to insure good contact..

I also recommend 5P minimum for a 500watt build (like a bafang CST + S12S controller) as 4P on nib contacts is really only workable on a 250w kit. I think about up to 375watts works OK on nib 4P setup too when I think about it, as this was the average draw amount I had on my ebike with PAS level 3-4 on a S12S controller.

This is the copper foil I have bought for my next build. I fold the copper over the top so the nibs have no chance of moving as they are stuck and wrapped inside the copper foil. Then place standard tape over the top to minimize electrical short possibilities.
http://www.ebay.com/itm/60mm-10m-Pickguards-Guitar-COPPER-Foil-EMI-Shield-Tape-/360262465752?hash=item53e150f8d8

This pic below is a shot of my old build. When I placed it inside a 09 dolphin case which was by far the most difficult part of the project due to the cases size.
file.php
 
I want to peak a bit above 2000W in 10S 1P with 26650 cells, need to experiment but with thicker copper link like on welded packs it should do the job?
With 15mm x 3mm and N52 magnets it gives more than 3, 5 kg of attractive force for each magnet, multiply per 2 for each cell and you have at least 7kg of pinching force holding the cell.

Also did you try to pinch copper between cell and copper instead? Shouldn't it allow better conductivity and less heat in the nibs (less current going through)?
 
Vanarian said:
I want to peak a bit above 2000W in 10S 1P with 26650 cells, need to experiment but with thicker copper link like on welded packs it should do the job?
With 15mm x 3mm and N52 magnets it gives more than 3, 5 kg of attractive force for each magnet, multiply per 2 for each cell and you have at least 7kg of pinching force holding the cell.

Also did you try to pinch copper between cell and copper instead? Shouldn't it allow better conductivity and less heat in the nibs (less current going through)?
I have oftened eyed 26650 cells for a NIB pack build but I haven't found any cells that I felt really good about since all the major band manufactures don't make them or are super expensive.
But 26650 cells would be heaps better for nib packs as you get twice as much surface area for contact especially for the positive side of the cell which is really the most lacking area.

What kind of motor/controller is it? For 2000w draw I would say you would want at least 6P even for 26650 cells. I never really done any serious tests and I have also only used Samsung 29E which aren't really considered 'high discharge' cells. So you might want to investigate what you can get out of it your self.
Also you might want to consider parabellum's pack design, he also did some heavy load testing..
https://endless-sphere.com/forums/viewtopic.php?f=14&t=66555&hilit=18650

These are some 26550 cells I considered this first one is 'bestfire' with a tested mAh capacity of 4616.5mAh but at $7.00 USD per cell (if you buy 5 more ) its pretty expensive for a dubious brand.
https://www.fasttech.com/products/1420/10013380/2261113-bestfire-imr26650-3-7v-6000mah-rechargeable-li-mp

Or maybe this 'Fandyfire' which has a test capacity of '3551.9 mAh' which is cheaper priced.
https://www.fasttech.com/products/1420/10000992/3237900-authentic-fandyfire-brc26650-3-7v-5000-mah
Don't know if you know much about this stuff but if you choose a cell from Fasttech make sure you get an unprotected cell so it has decent discharge capabilities...

These MNKE appear to be somewhat popular with vapists..
Here is some videos of them shorting them, its also a good video to show you never to use the cell if you have removed the positive part of the wrapping/short protector cover..
https://www.youtube.com/watch?v=cOBZGG_4Oaw
https://www.youtube.com/watch?v=nL2TT3darhY
 
riba2233 said:
Vanarian said:
Yes riba has an awesome spot welder but I just love the idea of having swappable cells with nothing else than fingers (and eventually a screwdriver) :p

If you buy proper cells they will never ever fail.

Well yes and no, for example I have no doubts that a a123 battery pack will hold for years before losing capacity but classic Li-ion chemistries may be more prone to lose capacity sooner. Kinda like a smartphone (not the best reference but somewhat) where after less than 1 year you have already started to lose capacity... Don't get me wrong I still understand that soldering is and remains the safer way to conduct power from batteries :p or at least the more stable way! But having bit more flexibility in case of cell failure / degradation is also cool.

TheBeastie said:
Vanarian said:
I want to peak a bit above 2000W in 10S 1P with 26650 cells, need to experiment but with thicker copper link like on welded packs it should do the job?
With 15mm x 3mm and N52 magnets it gives more than 3, 5 kg of attractive force for each magnet, multiply per 2 for each cell and you have at least 7kg of pinching force holding the cell.

Also did you try to pinch copper between cell and copper instead? Shouldn't it allow better conductivity and less heat in the nibs (less current going through)?
I have oftened eyed 26650 cells for a NIB pack build but I haven't found any cells that I felt really good about since all the major band manufactures don't make them or are super expensive.
But 26650 cells would be heaps better for nib packs as you get twice as much surface area for contact especially for the positive side of the cell which is really the most lacking area.

What kind of motor/controller is it? For 2000w draw I would say you would want at least 6P even for 26650 cells. I never really done any serious tests and I have also only used Samsung 29E which aren't really considered 'high discharge' cells. So you might want to investigate what you can get out of it your self.
Also you might want to consider parabellum's pack design, he also did some heavy load testing..
https://endless-sphere.com/forums/viewtopic.php?f=14&t=66555&hilit=18650

These are some 26550 cells I considered this first one is 'bestfire' with a tested mAh capacity of 4616.5mAh but at $7.00 USD per cell (if you buy 5 more ) its pretty expensive for a dubious brand.
https://www.fasttech.com/products/1420/10013380/2261113-bestfire-imr26650-3-7v-6000mah-rechargeable-li-mp

Or maybe this 'Fandyfire' which has a test capacity of '3551.9 mAh' which is cheaper priced.
https://www.fasttech.com/products/1420/10000992/3237900-authentic-fandyfire-brc26650-3-7v-5000-mah
Don't know if you know much about this stuff but if you choose a cell from Fasttech make sure you get an unprotected cell so it has decent discharge capabilities...

Thank you for the links !

The motor I want to drive is a tiny custom 60mm 85Kv from E-Max, paired with Vedder ESC (rated for 80A/12S continuous).

About Bestfire batteries the company is a guinea pig for Samsung (if I find back the link where I got that info I'll update my post) so the cells are in reality Samsung doing IRL tests of new chemistries. Actually in case of hazard the company taking blame would be Bestfire then. Not professionnal from cell manufacturer like Samsung IMO but still they make very good cells (be it their own brand or Bestfire underdog) so...

In 18650 format I've narrowed my cells choices down to Samsung 25R and a123 18650 cells but in 26650 format I've been looking at a123 M1 cells and this one from Bestfire https://www.fasttech.com/products/0/10013380/2261112-bestfire-imr26650-3-7v-4500mah-rechargeable-li-hp

This one has conservative continuous ratings at 70A not 90A like written (false advertisement :evil: ) but 70A is way enough for me. Only best result I've seen were M1B from a123.

The other one you linked is not as much competitive price wise once you need high current draws; its sibling in18650 format seems to hold good too but you'd rather get back to Samsung 25R. Looked for Sony Konions to but too many counterfeits.
 
Actually I think these soshines look pretty decent value. 5212.8mAh test capacity..
https://www.fasttech.com/products/1420/10002180/3486100-authentic-soshine-ncr26650-3-7v-5000mah
I think trying to expect a huge amount of current out of a non welded connection from a single cell is not a good idea.
 
True but I see a huge benefit from magnetic link : you can put wider strips which would require ultra powerful spot welder or multi layers and it will hold! You just need proper structure and powerful enough magnets.

I'm pretty sure a foolproof high amp setup can be build around this principle.
 
Vanarian said:
True but I see a huge benefit from magnetic link : you can put wider strips which would require ultra powerful spot welder or multi layers and it will hold! You just need proper structure and powerful enough magnets.

I'm pretty sure a foolproof high amp setup can be build around this principle.


With welding you can stack as much layers as you want, I know because I do that when I test welders, I just stack nickel as much as I want. On the other hand, magnets are loosing strength with distance so you are limited in that way.
 
I am updating my NIB pack build for the sakes of anyone that might be secretly interested... Everyone has different needs, I need a pack that doesn't need frequent charging, I aim for once a week, I don't have access wall power socket where I keep my bike..
My pack is now a 12S7P of 18650s Samsung 29Es. In case some don't know 29Es can discharge down to 2.5v..
http://lygte-info.dk/review/batteries2012/Samsung%20INR18650-29E%202900mAh%20%28Blue%29%20UK.html

I am using 60mm wide copper foil to connect the cells, one strip of copper foil connects the positive and negative sides of each cells.. This was the copper foil I used, one side is adhesive.. http://www.ebay.com/itm/60mm-10m-Pickguards-Guitar-COPPER-Foil-EMI-Shield-Tape-/360262465752?hash=item53e150f8d8
Doubling or tripling thin metal thin foil metal gives better cell terminal contour than a single thick ply of metal..
*Edit/Add* I have realized some folks aren't going to read this entire thread but I recommend you try.. So I have to point out one of the most important things you should do when trying to make these packs is use "Paper Insulation Gaskets" lots of different sizes on Fasttech.com
https://www.fasttech.com/products/1425/10012815/3748000
https://www.fasttech.com/products/1425/10012815/3952700
If you don't you might create a situation like this https://youtu.be/ZTzEHsJVZhA ..lots of lithium cell fires out there but how about a wound video? https://youtu.be/tnuKR0i4b-s

I also replaced my EM3EV bag with a Lunacycle bag, and also not using the Dolphine battery case at all atm.
The Trek logo is now easily visible and everything else looks a lot better on my bike now, the EM3EV bag overly covered the bike/frame.

On my last major full use of the battery pack I connected a power meter onto it, the pack cells were charged up to 4.16v each.
I rode around at an average of 350watts I would say and traveled 81 kilometers.
I weighed the pack and putting the cells aside the rest of the pack being wires, tape, and nibs added about an extra 550grams of weight I estimate from the weight of cells are 48g each.
The pack doesn't have a BMS and I charge it with a pure parallel balance battery charger, the pack is easily split-able in half with a simple removable link in the middle so I can charge at 6S on a BC168 or similar charger. With the middle link removed the charger sees the pack as 6S14P. It's very important to unplug the charger before reconnecting the middle link.

http://www.radiolink.com.cn/doce/product-detail-102.html
I did away with crappy unreliable JST connectors and instead used trailer connectors which are quite similar to bullet HXT lipo connectors but in a convenient 7 pin one way only style plug. All with thicker wiring gauge wiring then JST...
http://www.banggood.com/7-Pins-12n-Trailer-Caravan-Towing-Electrics-Plug-Socket-Towbar-p-955839.html

I soldered the connector/male plug directly onto the BC168 type charger.
http://www.banggood.com/Tirol-Wire-Connector-7-Pin-12V-Trailer-Heavy-Plastic-Plug-Connector-p-957602.html

I think the construction is self explanatory but I will try and fill in some bits.. it uses standard 18650 cell separators..
I wrapped the whole thing in kapton tape..
When using the 60mm copper foil I placed the foil directly over the bare cell terminals.. and then the nibs on top and there is enough copper foil on the sides to wrap over the top of the nib magnets so they can never jump.. It effectively becomes a whole 7P 2S copper tab strip with magnets on the inside..
The magnets are placed all with the same uniform polarity, this way they all tend to oppose each other from jumping naturally.

https://goo.gl/photos/yUKvST37ntZ3gPy27
Every time I have looked at it over the last few months of using it I ask my self "is this safer then my lipo packs?" and the answer for me is yes. If you had to ask me the question whether it would be safer for you, then I would probably be forced to say no because you shouldn't be asking me that question, you should have confidence in your own builds..

As you can see its no pack of beauty, I have always approached it with zero aim of impressing anyone.
I will probably edit this specific post and answer any questions to help make it a single informative post..
 

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Awesome setup you got there!

Another way to do it, and I thought about doing it this way. Just to give people even MORE options, and to expand their minds,

Use the correct size magnet with the holders and use epoxy over top of the magnet, even on the outter sides of the magnet, so the magnets dont move or short anything out. Can use the nickel too, even use thicker nickel strips that are harder to spot weld. Can also place plastic over top of that as well and duct tape it all really good.

I seriously thought about doing it that way. I'd say thought for the opposite pole of the outter can, you need to have a safety margin so for example my a123's M1B's I think a 9 or 10mm diameter neo N52 magent would have good spacing between the battery can terminal and the outter case. If that touched it would cause a short. That is why epoxy would work great, magnets would never move and its easy to grind epoxy down, or knock it off with a flat head screwdriver.
 
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