JP spot welder

[parabellum]

You can do whatever you want but I prefer to tackle my problems with elegance, not metal clamps on thin walled batteries.
The magnetic clamp I designed doesn't leave any space. They touch each other before and after being welded.

Really? How is the diameter discrepancy addressed in those holders?

 

[dssguy1]

Two ways I guess.
1) The holder doesn't have to be perfect, the magnets will draw the batteries into the holder so as long as you don't have the cradle cutouts too small, they will all touch eachother.

2) If you are using larger batteries than what this cradle holds perfectly, just scale it up .5% and you will have the same scenario I described above.


I guess I didn't do the trigonometry to make sure this would work for every size / type of 18650. I just designed it in 20 minutes and printed it in 30 minutes and moved on to my next project.

I've already made a replacement for my Dyson hand vac battery with it and all cells are touching eachother. I put a line of hot glue between them all just to be safe (Dyson did this on their stock battery packs as well).

 

[parabellum]

Two ways I guess.
1) The holder doesn't have to be perfect, the magnets will draw the batteries into the holder so as long as you don't have the cradle cutouts too small, they will all touch eachother.

2) If you are using larger batteries than what this cradle holds perfectly, just scale it up .5% and you will have the same scenario I described above.


I guess I didn't do the trigonometry to make sure this would work for every size / type of 18650. I just designed it in 20 minutes and printed it in 30 minutes and moved on to my next project.

I've already made a replacement for my Dyson hand vac battery with it and all cells are touching eachother. I put a line of hot glue between them all just to be safe (Dyson did this on their stock battery packs as well).

Cool. I believe if the magnets are placed alternating poles NSNSNSNSN... then it could be just flat board, batteries would stick together in row automatically. Right?

 

[dssguy1]

You could probably just get a long bar magnet and put them all in a row and they should stick to the magnet regardless of pole because they are ferrous metal.

 

[marty]

When you take apart Makita power tool batteries you find a rubber part that could be used as a battery holder.

 

[tomjasz]

You can do whatever you want but I prefer to tackle my problems with elegance, not metal clamps on thin walled batteries.
The magnetic clamp I designed doesn't leave any space. They touch each other before and after being welded.

Really? How is the diameter discrepancy addressed in those holders?

So far I've had 10 different 18650 cells, all were a fit in the clamps I have from my POS Sunkko welder. I don't find them all that useful. Especially when constructing a larger pack, i.e. 13s4p. I guess if I were making the p first, but meh. I don't find any drift in sizing when using new cells. LG, Panasonic, and Samsung are all pretty damn consistent. Are you seeing size differences in salvage packs?

 

[Offroader]

I am going to build a 20s12p 18650 pack (100 amps. Can someone recommend the tabs to use to weld this together.

Maybe send a link on what to buy.

Thanks

 

[riba2233]

http://www.ebay.com/itm/99-96-Pure-Nickel-Ni-Metal-Foil-Thin-Sheet-0-2mm-x-90mm-x-1000mm-EYL-3-/181472007058?hash=item2a40931392:g:MAcAAOxyeZNTSPEu


Something like this if you feel confident enough, if not, use nickel-copper combination. (nickel for parallel, copper for series connection)

 

[rio9210]

http://www.ebay.com/itm/99-96-Pure-Nickel-Ni-Metal-Foil-Thin-Sheet-0-2mm-x-90mm-x-1000mm-EYL-3-/181472007058?hash=item2a40931392:g:MAcAAOxyeZNTSPEu


Something like this if you feel confident enough, if not, use nickel-copper combination. (nickel for parallel, copper for series connection)

Why do you suggest copper ? 0,15x8mm pure nickel strip isn`t enough ?

 

[pucksterpete]

Does anyone have any video of this thing in action?

 

[fortisi876]

Does anyone have any video of this thing in action?

There's a link in the first post.

 

[riba2233]

http://www.ebay.com/itm/99-96-Pure-Nickel-Ni-Metal-Foil-Thin-Sheet-0-2mm-x-90mm-x-1000mm-EYL-3-/181472007058?hash=item2a40931392:g:MAcAAOxyeZNTSPEu


Something like this if you feel confident enough, if not, use nickel-copper combination. (nickel for parallel, copper for series connection)

Why do you suggest copper ? 0,15x8mm pure nickel strip isn`t enough ?

Well, it depends, it can be enough for very low currents. But for any meaningful currents, you need either thicker nickel or copper for series connections.

 

[rio9210]

http://www.ebay.com/itm/99-96-Pure-Nickel-Ni-Metal-Foil-Thin-Sheet-0-2mm-x-90mm-x-1000mm-EYL-3-/181472007058?hash=item2a40931392:g:MAcAAOxyeZNTSPEu


Something like this if you feel confident enough, if not, use nickel-copper combination. (nickel for parallel, copper for series connection)

Why do you suggest copper ? 0,15x8mm pure nickel strip isn`t enough ?

Well, it depends, it can be enough for very low currents. But for any meaningful currents, you need either thicker nickel or copper for series connections.

Which is the amper limit for 0,15x8mm pure nickel ? I plan to build a 10S6P 36V battery (21 Ah total) and I have this nickel strip, I`ve just bought your solder for this job mainly...

 

[lox897]

I can't find any batteries in Australia that will work with this. Where did you buy yours?

 

[redmonkey01]

I can't find any batteries in Australia that will work with this. Where did you buy yours?

Are there no cars in Australia? It's the battery in your car or truck. If you weld very rarely or just for one project pull the one out of your car, otherwise you can go buy one at an automotive/car store.

I haven't been to Australia, but I sure hope they have cars there

 

[dssguy1]

+1

If you can't figure out how to buy a 12v car battery.....this may not be the hobby for you.

 

[Kepler]

No car batteries in Australia. We run our cars on brown coal.

 

[ohzee]

Just received my new battery electrodes and cables. Extremely impressed. Going to be so much easier using these now.
Before I was worried about my a123 20ah tabs because of all the movement required. Just looking at the picture showing
them in a circle shows how playable they are.

Thanks Riba great improvement.

 

[riba2233]

I can't find any batteries in Australia that will work with this. Where did you buy yours?

Every car parts store should have one, in Croatia they sell them even at gas stations.

Which is the amper limit for 0,15x8mm pure nickel ? I plan to build a 10S6P 36V battery (21 Ah total) and I have this nickel strip, I`ve just bought your solder for this job mainly...

I don't want to speak from my mind, so here you go, whole thread including amp tables and other useful stuff:

https://endless-sphere.com/forums/viewtopic.php?f=14&t=68005

You could use thin nickel, it would work because cells absorb heat from nickel strips well, but there are losses that can be avoided.

I like this style:

This is nickel in combination with silver coated copper wire, can carry all amps you want

Just received my new battery electrodes and cables. Extremely impressed. Going to be so much easier using these now.
Before I was worried about my a123 20ah tabs because of all the movement required. Just looking at the picture showing
them in a circle shows how playable they are.

Thanks Riba great improvement.

Thank you a lot, I'm really glad you like them and I hope they'll serve you well

 

[Offroader]

How do I figure out the best way to connect the cells with nickel tabs for best series contact? In a 20s12P configuration.

I'm going to build a pack with 240 cells laid out like shown in the picture.

Is there a computer software that can line up the cells in the most efficient way?

 

[rio9210]

This is my final setup with JP SPOT WELDER REV 2.0, as is stated on PCB

Lenght of cable (10-25 mm) is 70 cm, as suggested by riba2233. The welder part is 20+50cm. Used two DINSE connectors (10-25 mm) with two brass tips soldered on the end of DINSE connectors (industrial solder process, not homemade - you have to find the guy that can do this for you). Heatshrink was used on cable-DINSE junction, and two brass battery connectors.
I could not get a set-up cheaper than this. Frankly speaking, I didn't get far from riba 2233's cost.

By the way, 6 nickel strips 0,15x8mm (soldered between parallel rows of 18650 batteries) carrying 5-6 A each one should be enough for a 10S6P 21 Ah battery, right ? I don`t want to bother with manually soldering copper wires if I can do the same job with the spot welder and nickel strips.

 

[tomjasz]

How do I figure out the best way to connect the cells with nickel tabs for best series contact? In a 20s12P configuration.

I'm going to build a pack with 240 cells laid out like shown in the picture.

Is there a computer software that can line up the cells in the most efficient way?

Se if Nobuo will help. He's really quite good. A important part of design is understanding where additional nickel should be soldered in to keep the connection cool and efficiently carrying the load.

 

[lox897]

I have looked on heaps of car battery websites. The only ones I could find were these: http://www.giantpower.com.au/45ah-12v-agm-deep-cycle-battery
Maybe your country has a wider range of batteries because I can barely find any.

 

[dssguy1]

Does your country have auto parts stores? They will surely have car batteries.....

 

[Lurkin]

I can't find any batteries in Australia that will work with this. Where did you buy yours?

I'm really hoping your trolling.

Go to your local Repco, Autobarn, Supercheap Auto...... or being a cheapo, a wreakers. Yes, there is plenty of them here.... 8)