any way to create packs without soldering?

RayGenWurm

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Sep 13, 2018
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Hey everybody,

i am messing around with li-ion cells for some months now.
Till now i managed to repair some products by replacing one or more dead cells (like AEG vacuum cleaners...)

But since i started in this area i was allways thinking about making myself a nice little backup-battery.
i do not own a solar panel - its more like because of the fun of it.

So far i tried to repair packs by soldering in the new cells but i am having big problems with that.
(try to not heat up the cell too much, i need lots of solder, most of the time the solder does not really stick to the surface of the cell...)

I know a better way would be spot welding but i dont have any experience in welding and im not sure if its really worth for me to buy a spot welder.
So after all i would like to ask you if you know a way to build battery packs without soldering / welding.
Best would be any anything where you just "click-in" the cells for example like the batteries in a tv remote.

Any ideas?

thanks,
 
There are several out there, but you will need to research

We are not alowed to name one on this site as naming it is banned. Several users have had success with it.

About 6 months back there was a new system coming out of India but have not heard much since original hype.

Some here just purchase the leaf spring battery holders

All options are expensive compared to hand solder

Also many options to build your own equipment own a battery
 
oh okay,

well would it be allowed to message some names?
or any hints.. i have no idea what to search for...
 
You can use the standard cheap holders that use a silver tab. These will probably be fine with low current draws, sub-200mA. I think they are just chrome plated steel. I have not tested this, just a guess due to the high resistance.

You can get the other type of holders that use brass or beryllium contacts. These have a much lower resistance and hold a lot tighter and won't corrode, rust or oxidize. They may tarnish slightly, but better than rusting/oxidation.

There's also the many ways you can build one yourself. Plastic pipe with a flip top comes to mind. Or 3D print something.




btw, here's a previous thread that talked about this exact issue:
https://secondlifestorage.com/t-18650-cell-holders-instead-of-soldering
 
If you have trouble soldering the cells you just need a bigger iron with higher thermal capacity. Cells can easily be soldered and a suitable iron is pretty cheap so it might be worth it even for small amounts of work.

Spot welding is the way to go when you are doing lots of cells. Probably not worth it for just a few cells, buying is too expensive for this and making a welder yourself requires knowledge and time, probably not worth it either.

And then, as mentioned, are cell holders which are suitable for low current applications. For 18650s they are easy to get, for other sizes of lithium cells probably not as easy. They offer the whole click-in experience and make it very comfortable but aren't suitable for high currents because of the small contacts.
 
Chablis_m The F system itself got banned due to their approach regarding it and we then later on saw so many flaws in it that they didnt accept as flaws.

Its good idea but the way they put it together was bad. Yes some have it working for sure but there is so many that it failed for during build or later on that we decided not to promote it untill those issues have been sorted.

There are some more systems but the closes working is normal holders. Works but its expensive. The easiest non soldering is proper spot-welding. Yes it cost but its not cheap what we do :)
 
You can get spot welders for a good price. Buying cell holders will be more expensive for big packs. What are you planning to build? What Size?
 
There are a growing number of folks that are 3D printing holders and just purchasing the tabs/springs

Having a dedicated thread just for open source 3d options for our Hobby would be great to start and keep updated.


Took a while to find but here is the old thread on the subject of the new at the time Nishi system

https://secondlifestorage.com/t-Nis...-pack-building-kit-from-India?highlight=india

The NESE system can be found here

https://secondlifestorage.com/t-SELLING-18650-NESE-modules?highlight=Agnius

Thread 20 of Nishi system refers to the F-Systyem, the Nishi system, and the NESE system from Agnius as current players

The thread somewhat leaves use in the dark about the results of testing.

Hope this helps
 
I know this is a older post. And this is my first reply .
If you watch some yt videos. There are several that have built a welder using a car battery, a solenoid and some ohther items of sorts

Not a hard build. And will be how I go about it.

Nothing you cant do.
 
Drmac said:
I know this is a older post. And this is my first reply .
If you watch some yt videos. There are several that have built a welder using a car battery, a solenoid and some ohther items of sorts

Not a hard build. And will be how I go about it.

Nothing you cant do.

It is worth using a system controlled by a microcontroller. Especially if you plan on doing a lot of spot welding. There are problems with solinods sticking shut. Also it gives you far greater control, as you can control the exact duration of the weld.

There are plenty of projects on this site and elsewhere on the internet. Look for Aruino spot welder. Or look at some pre make kits like the K-Weld.
 
Or learn to solder, if solder gets older than 6 months+ the resin inside hardens out(oxigen), and its useless.
Take a 50cm off and throw that away.
I had a solder wire of a kilo, bought 20! years ago, i had to take 1 meter of to reach the "good" part again.
For soldering cells, take a 100w soldering iron.
But make your choice wise, you got 100w solder irons that reach to 500 degrees celsius!
They will oxidise the lead, not vape(lead fumes) it, but oxidise, buy a cheap one for around 7-10$ at ~300-350 or something.

Both will work on cells, but its better to buy one at 300-350C.
You will be fine.
And its easier to repair if something happened or you want to check the whole pack after 1 or 2 years.

But this is my opinion, get a second thought on this.

Best

PS never ever use s39 or simular....NEVER...it will eat your copper away, and give you "contact disturbance"(freely translated).
Despite all those ytbyeee vcr's don't use it, learn to solder without that stuff
 
A serious DIY youtuber @jehugarcia has initiated a project to build full scale powerwalls using stackable circuit boards with 18650 cell holders. Its gotten pretty sophisticated to include BMS(s) and LED based charge levels etc. There is expense/work to buy/put-together these PCB units BUT... you can just snap in the cells :)
Here's a sample youtube
to give you the idea. On his site he has several youtubes and place to purchase.

*I am NOT pushing this, just seemed like a reasonable alternative to soldering for a serious powerwall if $ is not an object.
 
Those boards are not designed to be used at the currents required for a powerwall. They are also prohibitively expensive to build a powerwall from. They are fine for small projects. But anything requiring more than about 15A it is no good. rev0 (here on the forum) is the original builder and tester of those boards. Please check out the threads pertaining to the "Jehu Board" before using them.

There is also someone else who made an offshoot of this project, and they did a worse job in the design by not using enough trace width and/or solder traces to handle the current. These things are going to get someones house burned down, I'm afraid.



Ohhh, just took a quick look at the video. This is one where he is paralleling cheap chinesium bms units. No 2 chinesium bms units are identical, and they will eventually fight each other, especially under heavy load/charge. When 1 unit shuts off, the surge of current through the other 2 could blow them out before they trigger.
 
OffGridInTheCity said:
*I am NOT pushing this, just seemed like a reasonable alternative to soldering for a serious powerwall if $ is not an object.

If $ isn't an object then it make much more sense to buy lots of ex EV cells and simply bolt them together, I fail to see any merit in spending a significant fraction of the projects total cost on electrically suspect holders.
 
+1, used a controlled welder
Actually doing spot welding is pretty easy
- hold tips firmly on nickel strip
- press the foot pedal
done!
Others have experimented a bit to find the right settings on some dead cells.
Or like said above, a bigger soldering iron is an easy cheap fix.
 
So I also went the homemade spot welder from a car battery and solenoid route. I'm not going to openly suggest it as a better alternative to an actual spot welder off the shelf but I can tell you that I actually had great success with it. That is to say, after I blew thru about a dozen cells and trained my finger to hit the momentary switch for the exact precise millisecond I had great success with it. So just be warned, it's much more dangerous to go that way but, if you feel confident you know what to do, it could be a viable solution for a smaller pack. I think mine cost me no more $60 and one hour of assembly time all in.

Just a couple of things, a lotta the builders on YouTube that show how they created theirs say they don't have to charge them very often, however that wasn't my experience at all. I probably had to charge it after about spot welding every 60 cells. I think my battery was much smaller than theirs perhaps. I would suggest taking it outside when charging for safety sake.

Also, you REALLY need to be aware of cold cranking amps on the battery and will probably have to experiment with what works for your project. Again, on YouTube, a lot of the builders says you can go up to like 600 CCA but I definitely needed to stay below 300 CCA otherwise I was burning thru almost anything. My battery was also more of a tractor Lawn & Garden battery, rather than a true car battery.

Then I would suggest mounting the momentary switch to anything that is stationary and easy to reach. Keeping it free and open and just held in your palm makes it way too easy to hold down that button for just a millisecond longer thus getting a bad weld or blowing thru the cell itself.

Finally, a pro tip is to make your welding contacts, whether that's on pivoting arms or more of a welding pen, be spring loaded. I learned the hard way that that makes things SO much easier in terms of correct pressure and getting good contact between the copper, nickel and cell cathode/anode. Both suspension springs and compression springs are super cheap and made the welding process so much more enjoyable. Pictures of my DIY spring loaded pen and arm monstrosity are below (ended up making both for convenience sake and I was not going for looks or professionalism as you might be able to tell).


image_fzfgxf.jpg

image_ocviro.jpg


FYI I was never able to properly weld fuse wire or glass fuse legs directly to the battery anode, so, instead, I would just solder one leg of the fuse to a small tab of nickel and then weld that nickel tab to the anode. Definitely more time consuming than just using a spot welder that can successfully weld thin wire but, hey, it worked. For my larger packs, I may end up getting a real spot welder.
 
Nice little DIY setup ya got there.
The reason you have to recharge so often is because you are using the lawnmower battery, and something that is 300CCA range.

I would recommend going a little further into the project and build the proper timer adjustments with the FETs and triggers so you can use any battery and really dial in the duration needed.
 
Korishan said:
Nice little DIY setup ya got there.
The reason you have to recharge so often is because you are using the lawnmower battery, and something that is 300CCA range.

I would recommend going a little further into the project and build the proper timer adjustments with the FETs and triggers so you can use any battery and really dial in the duration needed.

Thank you sir and, yes, agreed, for big packs or any type of consistency, I definitely need to get some type of timing integrated into it. This is the part where I wonder if it's worth it taking the time to source and learn everything or if I just roll the dice on the sunkko 709AD version that's currently in the marketplace board. Only have 110V plugs though so kinda concerned about that since everyone seems to say that version is real weak. I can't seem to find the kweld in stock anywhere either so we'll see.
 
OhmGrown said:
Korishan said:
Nice little DIY setup ya got there.
The reason you have to recharge so often is because you are using the lawnmower battery, and something that is 300CCA range.

I would recommend going a little further into the project and build the proper timer adjustments with the FETs and triggers so you can use any battery and really dial in the duration needed.

Thank you sir and, yes, agreed, for big packs or any type of consistency, I definitely need to get some type of timing integrated into it. This is the part where I wonder if it's worth it taking the time to source and learn everything or if I just roll the dice on the sunkko 709AD version that's currently in the marketplace board. Only have 110V plugs though so kinda concerned about that since everyone seems to say that version is real weak. I can't seem to find the kweld in stock anywhere either so we'll see.

Check out this thread -https://secondlifestorage.com/t-Spot-welder-spotwelder-choosing-the-right-one
 
Geek said:
OhmGrown said:
Korishan said:
Nice little DIY setup ya got there.
The reason you have to recharge so often is because you are using the lawnmower battery, and something that is 300CCA range.

I would recommend going a little further into the project and build the proper timer adjustments with the FETs and triggers so you can use any battery and really dial in the duration needed.

Thank you sir and, yes, agreed, for big packs or any type of consistency, I definitely need to get some type of timing integrated into it. This is the part where I wonder if it's worth it taking the time to source and learn everything or if I just roll the dice on the sunkko 709AD version that's currently in the marketplace board. Only have 110V plugs though so kinda concerned about that since everyone seems to say that version is real weak. I can't seem to find the kweld in stock anywhere either so we'll see.

Check out this thread -https://secondlifestorage.com/t-Spot-welder-spotwelder-choosing-the-right-one

That's definitely good info, thank you. I didn't even know about the malectrics unit and seems like a lotta people on here like it. I'll be checking that out for sure.
 
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