Which Budget Spot Welder Should I Buy for a Few Battery Packs?

[atlet]

Hey everyone,

I'm planning to build a few battery packs (2x 10s2p and 1x 10s3p), so I’m looking for a budget-friendly spot welder that can handle the job without too much hassle.

I've been browsing AliExpress and found a few options, but I’m not sure which one (if any) would be a good fit:

• Option 1
• Option 2
• Option 3
• Option 4
• Option 5
• Option 6

Has anyone used any of these? Are they reliable enough for a small project like mine? I'm mainly working with 18650 cells and nickel strip.

Any advice or alternative suggestions would be super appreciated! I'm from Europe.

Thanks!

 

[scianiac]

Buy one of the ones this guy has modded and do his mods, most of these have flaws in the circuit design that means while they do work they don't work for very long. The mods are pretty easy. Luca

Obviously they still won't be as good as a more expensive unit but that is same as any other inexpensive vs cheap tool.

 

[docw009]

Options 1-5 are no good, Not very powerful, and the internal batteries will only last a few welding sessions. I've tried units similar to #5, and that's wat happened.

Option 6 requires an external battery like this 3S Lipo battery, and a hobby RC charger, or a large car battery. I use an earlier version of Option 6, also modified as described by Luca. Bought it in 2021 and done several thousand welds on .10 and .15mm nickel. Works better with Lipo than car battery, You have to discharge the Lipo to storage levels when not used or it swells up.

In hindsight. could have bought a better unit in first place. or jumped directly to the cheap red welder. Learning curve.

 

[James340]

I am not affiliated with any one but I did purchase this unit. Has 12 mosfet.I have used it with a car battery to convert 10s4p&10s5p to 13s3p.

 

[James340]

Options 1-5 are no good, Not very powerful, and the internal batteries will only last a few welding sessions. I've tried units similar to #5, and that's wat happened.

Option 6 requires an external battery like this 3S Lipo battery, and a hobby RC charger, or a large car battery. I use an earlier version of Option 6, also modified as described by Luca. Bought it in 2021 and done several thousand welds on .10 and .15mm nickel. Works better with Lipo than car battery, You have to discharge the Lipo to storage levels when not used or it swells up.

In hindsight. could have bought a better unit in first place. or jumped directly to the cheap red welder. Learning curve.

You think Lithium cells would work better than a car battery?Perhaps 3s3p

 

[BlueSwordM]

As always, I recommend supercap welders.

Here's the best ''budget'' one:

https://www.aliexpress.com/item/1005007101175633.html

 

[docw009]

You think Lithium cells would work better than a car battery?Perhaps 3s3p

If you mean 18650 and 21700? Not enough C rate. More P, and I don't know how much.

The 5Ah Lipo packs I used are advertised at 100-140C. That would be 100x5 or 500 amps, up to 140x5 or 700A instantaneous current, These little welders have been indirectly measured at currents in that range.

PS, I tried your welder when it first came out. They only put six MOSFET's on the front, leaving the rear empty. It was indeed very powerful, but it blew up, That's 20 bucks wasted.

 

[scianiac]

It's funny they put more mosfets on them like that is going to solve any of their issues, I think these basically never fail from overcurrent spiking the mosfets. They either fail from crap fet driving design like luca has outlined or voltage spikes because they basically only use the fets internal diode to suppress those. On mine I did luca's mods and then added diodes and TVS to protect the mosfets from voltage spikes. I haven't got a chance to use it a lot but seems to work well using 3S SPIM08HP batteries. Which are cheap high current pouch cells. This is two cells in parellel it seems so twice as much as I've been using and I picked the worst cells from my lot anyway but: SPIM08HP 3.7V 16AH - Excellent Lithium Ion Power Cells Plenty of other cell options of course.

 

[James340]

If you mean 18650 and 21700? Not enough C rate. More P, and I don't know how much.

The 5Ah Lipo packs I used are advertised at 100-140C. That would be 100x5 or 500 amps, up to 140x5 or 700A instantaneous current, These little welders have been indirectly measured at currents in that range.

PS, I tried your welder when it first came out. They only put six MOSFET's on the front, leaving the rear empty. It was indeed very powerful, but it blew up, That's 20 bucks wasted.

I will keep using the 13 years old Optima battery. The welder I received has all 12 but I didn't do a lot of welds&didn't get it hot

 

[atlet]

Ok, I looked ad Luca videos and the one that has all issues resolved and don't need and mod is WISE MAPLE version.

 

[docw009]

Ok, I looked ad Luca videos and the one that has all issues resolved and don't need and mod is WISE MAPLE version.

Right, I bought a red welder in late 2021 and the simple capacitor mod worked. I hadn't seen this video and he explains it well, I remember that the Wise Maple version was said not to need any mods.

With the chinese market ,successful product gets copied, sometimes poorly. If they don't want to redesign, maybe they just use the name. That's why most of the red welders had flaws. It couldn't have been the original designer putting out variations that didn't work in the field. Lots of fakes out there,

Your option #6 is a different welder than the one that worked in 2021. Might work. Who knows. It's cheap enough to roll the dice, but you still need a battery, I suggest you listen to BlueSwordM's experience.

As always, I recommend supercap welders.

Here's the best ''budget'' one:

https://www.aliexpress.com/item/1005007101175633.html

.

 

[atlet]

Right, I bought a red welder in late 2021 and the simple capacitor mod worked. I hadn't seen this video and he explains it well, I remember that the Wise Maple version was said not to need any mods.

With the chinese market ,successful product gets copied, sometimes poorly. If they don't want to redesign, maybe they just use the name. That's why most of the red welders had flaws. It couldn't have been the original designer putting out variations that didn't work in the field. Lots of fakes out there,

Your option #6 is a different welder than the one that worked in 2021. Might work. Who knows. It's cheap enough to roll the dice, but you still need a battery, I suggest you listen to BlueSwordM's experience.



.

Yes, I think this is the cheapest options as for red welder I need a battery.

 

[atlet]

What about FNIRSI SWM-10? It has a lot of good reviews.

 

[docw009]

What about FNIRSI SWM-10? It has a lot of good reviews.

Kerry Wong's youtube review? He was given the unit and it shows. No pull test. No welds on real nickel. Then read the comments from owners below.. I sure wouldn't want this. The internal Lipos died .

 

[atlet]

Kerry Wong's youtube review? He was given the unit and it shows. No pull test. No welds on real nickel. Then read the comments from owners below.. I sure wouldn't want this. The internal Lipos died .

Ok. I saw other videos and it seems that is welding good also 0.2 nickel strips. I'm searching for K7-PRO but I don' se a lot of reviews and how tick nickel strips can weld. It's reliable?

What about Glitter 801A spot welder?

 

[BlueSwordM]

Ok. I saw other videos and it seems that is welding good also 0.2 nickel strips. I'm searching for K7-PRO but I don' se a lot of reviews and how tick nickel strips can weld. It's reliable?

What about Glitter 801A spot welder?

The Kekk K7 Pro uses a really high quality PCB, with 9x MOSFETs, a nice TVS diode and best of all, a high quality firmware

I actually received a Kekk K7 Pro PCB recently to replace the old one I had, and its capabilities are sooo much better it's insane.

I can weld 0.1mm copper no problem with it at my current settings with it, which is insane considering we're talking about a portable welder.