Bruh I am so jealous, building a battery pack with 45d cellsI have built my first battery, 20s10p, with BAK INR2170-45D cells. I did some tests with 0.1 nickel + 0.15 copper on old 18650 cells with a <100€ spot welder. I wasnt able to seperate the nickel/copper sandwich from the cell without ripping off.
Combined with a ANT BMS: 575A, continuous 230A.
A little bit off topic: Is it okay to use the parameters from this post?
ANT BMS need help
I got a new bms and I am having difficulty setting it up. It is a 340A continuous / 850 peak discharge 17-24S (20S for me) My pack is made of 10 Nissan Leaf modules wired in series for 76V / 40Ah for my electric motorcycle. I need help setting up the app and the input values. So far I have...endless-sphere.com
"Copper/nickel sandwich" buses for series connections
- Thread starter spinningmagnets
- Start date
Blacksheep Engineering
100 mW
To update on my battery situation, I ended up going with laser cut copper bus bars.
Final config is 28s 14p.
7.3kwh
630 peak amp rating
350 continuous amp rating
My motor will be pulling 364 amps peak power
Here is a link to the build thread I said I would make. Lots more info there if you're interested.
endless-sphere.com
Final config is 28s 14p.
7.3kwh
630 peak amp rating
350 continuous amp rating
My motor will be pulling 364 amps peak power
Here is a link to the build thread I said I would make. Lots more info there if you're interested.
Better than the Stark Varg? 76v 90Ah 35kw Dirtbike Build
Update on this, waiting on parts, I am going to use 3 6 gauge wires inside the battery. Hopefully 2 gauge after that but I cant find a connector that can fit anything bigger than 4 gauge. What are you guys using? Anything better than a QS-10? Is there any reason not to run wires straight out of...
endless-sphere.com
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Ali copper sheets work great. 30 J at the nickel spot ... (ali 200A rated ones. whatever they truly are, I don't know) I'll get back when I tested higher amps. I need 1200Amps thereabout for 0,1ms or something to work as my main battery to my kweld. I cross my fingers it will work when finished.
TLDR: I think folks may find some success spot welding copper strip directly to 18650's with copper flux. Glitter sells some and I've found some domestically at FDJ Tool. They both seem to work equally in the limited testing that I've done. I hope you guys can try it on your own and post the results.
Longer version is....ugh, I had a bunch typed but the long version is just way too long. Medium version is, I ended up with an absurd quantity of 33140 LifePo4 batteries and sold some to @Zambam who wanted them for his scooter. We've both been going through similar trials and tribulations together via private message on the best way to assemble these things, because they have a copper bus bar on top and that presents some challenges with spot welding. Soldering has been working great, FWIW. I ordered a Glitter 811H and went through some troubles with that thing, which I'll skip for now, but here's the result from the minimal testing I've done, which I'm hoping folks here have success with and take it further (my interests at the moment aren't really with 18650's).
I'm guessing the 33140 info isn't of much interest since it's mostly 18650's here, so I'll also skip that info for now, but a number of years ago I bought some used Tesla 18650's from a gent on ES and ended up selling them last summer, but still had ONE left in a flashlight and that's all I have for testing. The Glitter seems way too powerful for 0.1mm strip, like around the 1-2% setting range and there's no resolution left for trying to fine tune it, so it would be great if you guys could do some testing with flux using the Kweld, Malectrics, and whatever other lower power spot welders are out there.
What I can say is that with 0.2mm copper strip with the machine set at 3%, it seemed to work pretty well. E-bike applications are much more demanding than my solar/backup needs, so I can't say if this is good enough for the high-discharge world, but this weld was easily good enough for my needs. The bigger pit in the cell in the last pic is from when I initially tried it at 10% and it was way too much. Perhaps the settings with lower power spot welders can be dialed in such that it works well for you guys.
Longer version is....ugh, I had a bunch typed but the long version is just way too long. Medium version is, I ended up with an absurd quantity of 33140 LifePo4 batteries and sold some to @Zambam who wanted them for his scooter. We've both been going through similar trials and tribulations together via private message on the best way to assemble these things, because they have a copper bus bar on top and that presents some challenges with spot welding. Soldering has been working great, FWIW. I ordered a Glitter 811H and went through some troubles with that thing, which I'll skip for now, but here's the result from the minimal testing I've done, which I'm hoping folks here have success with and take it further (my interests at the moment aren't really with 18650's).
I'm guessing the 33140 info isn't of much interest since it's mostly 18650's here, so I'll also skip that info for now, but a number of years ago I bought some used Tesla 18650's from a gent on ES and ended up selling them last summer, but still had ONE left in a flashlight and that's all I have for testing. The Glitter seems way too powerful for 0.1mm strip, like around the 1-2% setting range and there's no resolution left for trying to fine tune it, so it would be great if you guys could do some testing with flux using the Kweld, Malectrics, and whatever other lower power spot welders are out there.
What I can say is that with 0.2mm copper strip with the machine set at 3%, it seemed to work pretty well. E-bike applications are much more demanding than my solar/backup needs, so I can't say if this is good enough for the high-discharge world, but this weld was easily good enough for my needs. The bigger pit in the cell in the last pic is from when I initially tried it at 10% and it was way too much. Perhaps the settings with lower power spot welders can be dialed in such that it works well for you guys.
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I got 750amps at the moment so I guess they are pretty good. I will look into if I can get more.
I have build and used a shorter copper strip today that I will try out tomorrow. I also did some DIY copper sandwich without welds on the copper parts... I think it will help but we'll se the results soon enough.
I have build and used a shorter copper strip today that I will try out tomorrow. I also did some DIY copper sandwich without welds on the copper parts... I think it will help but we'll se the results soon enough.
I think my copper inserts really worked!
Another pack I build for my kweld consisting of 3s12p Molicel P26A
Another pack I build for my kweld consisting of 3s12p Molicel P26A
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What are the opinions on these types of premade copper/nickel strips? I question if these can handle high ampacity as only nickel is being spot welded directly to the cells, making it the weak link.
It's been discussed before, so as long as you're making sure you're getting it from a reputable source with higher-quality nickel, the current path through nickel is very very short, then it gets to copper. You're right, it's not copper directly attached to the cells, but for some people that only have access to a simple spot welder, this type of product might be best of both worlds.
Using copper flux, your glitter 811H power setting had to be lowered to 3% to get a good weld with copper strip on the 18650, 10% was too high? How many amps approximately is 3% and 10%? Is the magic all in the copper flux?
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Correct, 10% was too high and caused that little pit in the cell as seen in the last pic.
I'm not sure what exactly the number represents. The manual lists the power setting as "Energy Grade" and then the numbers are listed with a "t", so what I've been calling 40%, is really 40t in the manual. The manual says the Energy Grade is "0-99T(0.2ms/T)". It also says, "Please choose the proper energy grade and pulse current according to different object materials and thicknesses." and "The higher the energy level, the greater the output current". I'm just not sure if the 10t setting on a 7000A max machine is 700A. I think it might be, but I'm not sure.
I tried the machine at first with no flux using copper strip on the copper top 33140 up to 80% and it was worthless, so I was initially thinking the flux wasn't going to do squat, but yeah, the proper flux was basically magic. It made all the difference.
I'm not sure what exactly the number represents. The manual lists the power setting as "Energy Grade" and then the numbers are listed with a "t", so what I've been calling 40%, is really 40t in the manual. The manual says the Energy Grade is "0-99T(0.2ms/T)". It also says, "Please choose the proper energy grade and pulse current according to different object materials and thicknesses." and "The higher the energy level, the greater the output current". I'm just not sure if the 10t setting on a 7000A max machine is 700A. I think it might be, but I'm not sure.
I tried the machine at first with no flux using copper strip on the copper top 33140 up to 80% and it was worthless, so I was initially thinking the flux wasn't going to do squat, but yeah, the proper flux was basically magic. It made all the difference.
If 10T is 700A, would that put it within the range of the Kweld?
The Kweld will trip at 2000A, but I also think that might not be entirely easy to get to the max 2000A from it. I think I've read that with a good battery, it's pretty easy to get ~1500A, which means the Kweld should easily be able to hit 700A, likely double that. I had one years ago and ended up selling it because it was collecting dust, kind of regretting it now. I sent an email to the NA distributor to see where they are located, but they haven't replied. If they're inside the US and if they respond tomorrow, I'll probably order one this weekend. The home site won't let you order to the US, kind of annoying. I send them an email too and haven't heard anything back. Not super impressed with the current levels of service, so I might look at other options.
The search result shows it's in Canadian dollars, which would roughly make sense to the pricing from Germany, but then when I add it to cart, it shows $249 in USD, so I have no clue what the deal is with the pricing. I'll be looking around to see what else is out there.
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After some light almost no usage the main cable to the Kweld unit was losing its connection and I got Vspot NE. and CAL numbres and also undercurrent errors.
The solutions that I found is bolt on type of connector lugg. Like the original on the unit side. You drill a hole in the copper on the battery side and bolt it on there as well.
A hammer and a chisel to make your own connector the raw way.
A lipo Banana connector loses 300A power only by using it. My esimates. 5.5mm are good but requires a very hot soldering iron 100W+.
I don't weld copper or sandwish with my Kweld or it can't or I'm not successful with it those attemtps I've made. I will try in the future when I get more time.
The solutions that I found is bolt on type of connector lugg. Like the original on the unit side. You drill a hole in the copper on the battery side and bolt it on there as well.
A hammer and a chisel to make your own connector the raw way.
A lipo Banana connector loses 300A power only by using it. My esimates. 5.5mm are good but requires a very hot soldering iron 100W+.
I don't weld copper or sandwish with my Kweld or it can't or I'm not successful with it those attemtps I've made. I will try in the future when I get more time.
Btw, have no one ever mentioned galvanic corrosion? It's a bad idea to sandwich plated steel with copper because of how dissimilar they are, the steel will eat away the copper after the plating is gone, copper and pure nickel is OK however.
Pure nickel plus copper...
I found out I got vspot NE errors again. CAL errors I mean I get 1200Amps and next I get undercurrent from a 30J spot weld.
I have 4mm banana contacts on one end and it had became blackened inside the connector brass metallic piece. I cleaned it with a small drill and pushed it together a bit to get a better and stronger fitment and it was as new again.
I don't know about voltage level and cell. My former pack of 2s10p 21700 cells was just about 800Amps and it may have been that the connection was lose all along there...
I think 3s is a better option for the kweld but I will try and se what my first 2s pack I build for this reason will perform after new leads and connectors.
YoshiMoshi
10 W
Excellent question!
Hummina Shadeeba
10 MW
I’m just guessing but I think since the steel being on the outside, and the copper and cell connection on the inside, even if there were enough moisture (electrolyte) and the steel corrodes, (which would happen and not the copper corroding nearly as much I think) I think the copper and cell connection will be left intact. A lot of I think
Could cover connections with paint or something to be sure
Or maybe lucky it’s a battery and the dc current will counter it?
“but can also be done by applying a direct current (DC) electrical power supply which counteracts the galvanic current that causes corrosion.”
Galvanic Corrosion of Steel and Other Metals
Galvanic corrosion may occur when two dissimilar metals are in contact with one another in the presence of an electrolyte creating an electronic pathway for the movement of electrons (such as water).
www.azom.com
Is polarity important ?
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BlueSwordM
100 W
- Joined
- Jul 23, 2018
- Messages
- 196
So, is there anything preventing us from using brass strips in place of nickel?
It has slightly higher conductivity than nickel, similar thermal conductivity and yet, it is dirt cheap.
All of these characteristics do seem to make a prime replacement material in place of nickel.
Why haven't I seen anything built with brass strips?
It has slightly higher conductivity than nickel, similar thermal conductivity and yet, it is dirt cheap.
All of these characteristics do seem to make a prime replacement material in place of nickel.
Why haven't I seen anything built with brass strips?
BlueSwordM
100 W
- Joined
- Jul 23, 2018
- Messages
- 196
The answer seems to be that zinc will get vaporized during the spot welding process, making the piece weaker.
Furtheremore, it'll get temperature hardened during that process, making it significantly less flexible and easier to snap.
In summary, just use 0.1mm copper + 0.1-0.2mm stainless steel and you'll be just fine for any mainstream style battery build.
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