18650 spot welding -how to- ULTIMATE REPOSITORY

Thanks,

well they are useful if you go overboard with power, and want to weld thicker materials more reliably. But not necessary for 99% users. You can make high current design even with 0.15 or 0.2 mm nickel, just like I've described in my previous post, or like litespeed described.
 
define high current :)

i'm planning on doing 30 amps on 52v , on panasonic pf, i've managed to obtain from nkon before they closed of their gates to israel, around 102 cells.

now i'm wondering if i should stick with a 7p14S or try and obtain the rest from a another supplier by smaller packages. and then run each cell with charge test (like using a charger does automatically charge and discharge 3 times) ..


another problem is i'd like to do a triangle pack, and with 7-8 groups i maybe run into an issue where one group has only 2 cells facing another group. i have no idea how many strips i should use.

i also am not sure how much do the slots in strips help in welding...
 
emaayan said:
define high current :)

i'm planning on doing 30 amps on 52v , on panasonic pf, i've managed to obtain from nkon before they closed of their gates to israel, around 102 cells.
Click to expand...

Draft a layout and define the parameters. Post the drawing here and on ES FB. Damian and Micah were kind enough to sort the nickel layout. Others will pitch in too. Then share the finished drawing with others. Don't over think...
 
"don't over think.." yea

well the INITIAL layout was something along the lines like this when i thought i would have all 124 cells from nkon
pack.JPG

i even thought of asking someone from ali-express to make me sheets or a roll of a 0.15 strip shaped like so,

runds.JPG

(as they also provide full strips https://www.aliexpress.com/item/99-96-Pure-Nickel-Ni-Metal-Foil-Thin-Sheet-0-15mm-x-130mm-wholesale-price-5kg/32419664636.html and can make custom shapes)

but now i'm not even sure about that, they keep telling to make sure my batteries are ordered from the supplier and from the same batch, but if i order my cells in groups of 30 cells each time, they are probably not from the same batch.
my em3ev is currently entering it's 4th year usage, and my estimates are it's has around 15AH (out of 25ah) thus i'm not exactly pressed for time,i want my pack to last as long as possible , so if i build a pack now, with only 7p , i would only have 18.2AH, (ok 20, but i'm always calculate by 90% charge) , so would it be worth just for 3 extra AH?

OTOH , if i start ordering cells in smaller quantities from another supplier, til i do reach the target destination, what method of validation, other then automatic charge test of 3 cycles to make sure they can be used together.

too many dependencies.
 
Overthinking. If you cant, get them all at once, you can't, just do it.
 
You can buy the full width sheet, and find someone locally with a CNC machine. A great idea if I say so myself.

My tab welder seems a little weak when trying to do two 0.10 from Supower I think I bought them from.
If I can do up another spot welder, adruino based or something, for a reasonable cost, I'd chaulk it up as a hobby/amusement cost.
 
just do what? get them from another supplier? how dangerous is it?
 
emaayan said:
just do what? get them from another supplier? how dangerous is it?
Click to expand...
If you think it's dangerous don't do it. I'd think it's FAR less dangerous than Lipo or salvage. I bought groups, but i only go as high as 70 batts in the biggest pack. I'm donwtuning to 36V in the coming years. The opposite of the direction most see are taking. Unfortunately I tested my bikes braking distances....
 
i don't have enough data to know if it's dangerous or not, i don't want to blow up or anything, this is probably the last battery i'll build, so i want to last as long as possible

my upper limit is 52v, and considering the fact that at 700 watts i usually do 35 kph, i'm pretty sure it's comparable to hubs at 36v, infact most of my ride is 35-40, i usually want less speed and more torque, for acceleration.

i have no idea how to do braking distance tests, would love to , it's one of the things i miss the most, i could fine tune it more by the tests.
 
emaayan said:
i don't have enough data to know if it's dangerous or not, i don't want to blow up or anything, this is probably the last battery i'll build, so i want to last as long as possible

my upper limit is 52v, and considering the fact that at 700 watts i usually do 35 kph, i'm pretty sure it's comparable to hubs at 36v, infact most of my ride is 35-40, i usually want less speed and more torque, for acceleration.

i have no idea how to do braking distance tests, would love to , it's one of the things i miss the most, i could fine tune it more by the tests.
Click to expand...

Grab a friend. Have them spot you. Ride toward the friend and have them signal you to stop. Ride at them at your normal cruising speed and when they signal do an emergency full stop. Measure the distance. It'll give you a rough but reasonably accurate idea. Using a friend to signal adds the reaction time. It spooked me as I increased speed, the distances grew significantly. It's also good to practice avoidance skills and swerving. Also with a mate who signals. See MSF training online.
 
My backup welder arrived! FAST shipping and super price. I wish we could ship registered mail as cheaply as this German fellow! WOW Fast and tracked all the way!

(best dummies too!)
 

Attachments

  • Screen Shot 2017-04-03 at 2.32.31 PM.png
    Screen Shot 2017-04-03 at 2.32.31 PM.png
    138.8 KB · Views: 2,436
tomjasz said:
My backup welder arrived! FAST shipping and super price. I wish we could ship registered mail as cheaply as this German fellow! WOW Fast and tracked all the way!

(best dummies too!)
Click to expand...

Can you post the link of this welder?

Why do you need a backup welder?
 
Offroader said:
Can you post the link of this welder?

Why do you need a backup welder?
Click to expand...
First off they're cheap. 1/3 of the cost of a POS China made.

Secondly I will soon depend on my welders to have batteries. I have backup parts for ALL my motors as well. I do not drive and it's biking season I have a backup bike as well. (actually 5, but two 25+mph)
 
Offroader said:
tomjasz said:
My backup welder arrived! FAST shipping and super price. I wish we could ship registered mail as cheaply as this German fellow! WOW Fast and tracked all the way!

(best dummies too!)
Click to expand...

Can you post the link of this welder?

Why do you need a backup welder?
Click to expand...

Just Google Arduino Battery Spot Welder. Easy Peasy. Google a number of ways... battery spot welder 12v

https://www.google.com/search?client=safari&rls=en&q=battery+spot+welder+12v&ie=UTF-8&oe=UTF-8

BTW order the 25th and arrived today from Germany REGISTERED mail so you will have to sign for it!
 
Allex said:
Always have backup, I have 2 just in case one brakes and I need to finish the job =)
Click to expand...

I agree and my spot welder broke twice, but now I just have an extra set of fets, and the programable micro chip. Usually those will be the most likely things to go, or they went on mine. Anything else you can quickly order them.
 
Offroader said:
Anything else you can quickly order them.
Click to expand...
Quickly doesn't help if you don't have the skill set developed. Old guys, some of us, learn more slowly. $80 is cheap insurance!

Any hints on WHY they went?
 
tomjasz said:
Just Google Arduino Battery Spot Welder. Easy Peasy. Google a number of ways... battery spot welder 12v

https://www.google.com/search?client=safari&rls=en&q=battery+spot+welder+12v&ie=UTF-8&oe=UTF-8

BTW order the 25th and arrived today from Germany REGISTERED mail so you will have to sign for it!
Click to expand...
It looks like his site is down now. Which channel did you use to contact him?
 
parabellum said:
tomjasz said:
Just Google Arduino Battery Spot Welder. Easy Peasy. Google a number of ways... battery spot welder 12v

https://www.google.com/search?client=safari&rls=en&q=battery+spot+welder+12v&ie=UTF-8&oe=UTF-8

BTW order the 25th and arrived today from Germany REGISTERED mail so you will have to sign for it!
Click to expand...
It looks like his site is down now. Which channel did you use to contact him?
Click to expand...
Go to tindie and search. It was about 4-5 hits down n the google post. Easy...

https://www.tindie.com/products/KaeptnBalu/diy-arduino-battery-spot-welder-v2-prebuilt-kit-/
 
He setup his own shop, it took a couple of days for it settle,
https://malectrics.eu/
 
The malectric version lists a 12v 2A 3s Lipo. Would 3s 18650 be sufficient? HG2?
 
I saw an overpriced probe set. Two probes set up close into a single handle. Has anyone worked out a homebuilt solution?

Called a welding pen...$50

Anyone have a solution?
 

Attachments

  • IMG_1218.JPG
    IMG_1218.JPG
    26.8 KB · Views: 3,922
  • IMG_1217.JPG
    IMG_1217.JPG
    88.9 KB · Views: 3,922
Didn't understand price either.
Gave up and just soldered wires directly to transformer output. Two hand operation but works perfectly.
QS9N1QH.png
 
Crossposting from my build thread to ask some pack assembly advice:

I am still at the point of having 20 out of 22 9p sub-packs constructed (see: https://imgur.com/a/gsK9c), I have the materials to finish the rest after ordering some replacement HG2 to replace the ones I blew up during my iterative welding/welder-development process.

I have also acquired a whole lot of 0.3mm flat nickel sheet, which I have cut into trapezoidal shapes to make a single series connection between two 9p packs.

I have found at the voltage levels that I previously recorded the welder having acceptable voltage overshoot (22-23V, 1.2-ish Farads), making test welds between 0.3mm nickel plates was not giving good weld adherence.

This is with a weld profile that I adopted designed to minimise arcing/exploding with capacitive discharge, over variation in surface conductivity: 500us (on), 1ms (off), 500us (on), 1ms (off), 8ms on. This profile has worked well at the power levels I have needed for 0.3mm nickel-to-cell-tab (nickel-plated steel, which seems to have a markedly different characteristic to pure nickel-nickel welds).

I think I have two options:

1) Modify my CD welder to have freewheeling diodes *as well as* the existing drain-source capacitive snubbers, which should make it robust enough to significantly increase the weld voltage and current, and so achieve direct 0.3mm nickel-nickel welding.

2) Using my pre-cut nickel plate, make the series connections using solder. This seems viable, as the cells now have nickel parallel buses attached, which could provide enough thermal mass and isolation to avoid overly heating the cells. It might be possible to use things like freeze-spray also and good surface prep to minimise heating.

Thoughts? I really need to get my act together and finish this thing huh.
 
jmz said:
Crossposting from my build thread to ask some pack assembly advice:

I am still at the point of having 20 out of 22 9p sub-packs constructed (see: https://imgur.com/a/gsK9c), I have the materials to finish the rest after ordering some replacement HG2 to replace the ones I blew up during my iterative welding/welder-development process.

I have also acquired a whole lot of 0.3mm flat nickel sheet, which I have cut into trapezoidal shapes to make a single series connection between two 9p packs.

I have found at the voltage levels that I previously recorded the welder having acceptable voltage overshoot (22-23V, 1.2-ish Farads), making test welds between 0.3mm nickel plates was not giving good weld adherence.

This is with a weld profile that I adopted designed to minimise arcing/exploding with capacitive discharge, over variation in surface conductivity: 500us (on), 1ms (off), 500us (on), 1ms (off), 8ms on. This profile has worked well at the power levels I have needed for 0.3mm nickel-to-cell-tab (nickel-plated steel, which seems to have a markedly different characteristic to pure nickel-nickel welds).

I think I have two options:

1) Modify my CD welder to have freewheeling diodes *as well as* the existing drain-source capacitive snubbers, which should make it robust enough to significantly increase the weld voltage and current, and so achieve direct 0.3mm nickel-nickel welding.

2) Using my pre-cut nickel plate, make the series connections using solder. This seems viable, as the cells now have nickel parallel buses attached, which could provide enough thermal mass and isolation to avoid overly heating the cells. It might be possible to use things like freeze-spray also and good surface prep to minimise heating.

Thoughts? I really need to get my act together and finish this thing huh.
Click to expand...

I experimented a lot with my 2F welder and .1mm copper & .3mm nickel tabs. I only used 2 pulses, was considering spreading the energy over more pulses to reduce chances of blowout.

I added discharge energy calculation to my welder to be able to fine tune welding energy that was spent.

The issue is that energies required to securely weld 0.3mm nickel are overlaping with the energy needed to cause a blowout, and short circuit within the battery (had it once - battery had an internal short and overheated in 5 seconds. Fortunately was an empty old cell). So even when I really fine tuned the energy level - still occasionally there would be a blowout. If you multiply even a 1% of a blowout with some 600welds needed for 100 cells welding the probability is quite high.

If you really wanted to pursue the .3mm nickel path I would use slotted .3mm with long slots or even completely slotted strip - meaning cutting it in half longitudinaly, to reduce needed weld energy. This tactic helped a lot with copper. Also using higher capacity but with lower voltage helped reduce chance of blowout.
 
You must log in or register to reply here.

Similar threads

Skyler
Real spot welding machines. Which is the better deal ?
Replies
3
Views
1,332
Skyler
Skyler
H
spot welder recommendation: Glitter vs Sunkko for .3mm pure
Replies
0
Views
485
Hempstaed
H
J
  • Question
Issues with spot welding
Replies
3
Views
556
justwannaweld
J
From-A-To-B
    • Like
BAK N18650CP - aluminum can, spot welding difficulty
Replies
7
Views
996
999zip999
999zip999
C
16s9p or 17s8p?
Replies
15
Views
789
calab
C
Back
Top