DIY Battery Tab Welder (using ATV battery)

So… I just made this spot welder today (this is my demo video below) and it works really well! Switching to a larger Van battery that puts out 800A shortly but at 200A this works a treat!


Interesting I’ve seen some instructables on making these as well but have read from comments around the interwebs the main problem is getting the timing figured out where you get a good weld but don’t too thoroughly cook the battery cells in the process… would be interested to hear what more experienced people have seen. Have you used this for actually working on cells at all yet?

Have also seen “legit” and “cheap” purpose made welders for battery tabs think they were around $140 or so, not really worth it for 1 battery but if you plan to keep making them maybe worth checking out (might be worse than this solution though dunno to be honest).

I weld a couple of cells together in the video at the end… I’ve tested them since, they seem to be absolutely fine.

Ah thought you were just referencing the video for the technique didn’t realize it was actually your vid… also just got to the battery part :slight_smile: the dangers of commenting while still watching.

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Yeah lol, it’s my video. I just threw it together today as I was bored waiting for my solenoid switch I ordered from eBay, so I butchered my old scooter that was sitting in the garage for one… :smiley:

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Where did you get this switch in the video? Looks like a good solution. Keep us updated when you use a new switch and a new battery :wink:.

It came off of my 50cc scooter that had been sitting in the garage for a few years! It’s only rated for 150A so I’ll need to upgrade it. I’ve just got a new van battery that’s 800A ! I’ll need to upgrade the copper electrodes to at least 2mm solid core and the wires I use to a higher AWG/GAUGE. I’ve got most of the material for tab welder version 2.0 :slight_smile:

Old battery and new 800A battery side by side…


Awesome, do you have an idea of the total cost excluding the battery? Thanks

Excluding the battery, if you bought the solenoid switch and wire off eBay, less that £20!

Awesome! I hate to keep asking you but do you have a link to a good reliable solenoid switch that would work with a car battery? If you could give me a link to the wire that would be sweet as well.

I am only finding switches like this on eBay.

Hi, Well that one will work, but you may have to replace it after a few hundred welds or so.

This one would be better and last a lot longer:-

And this is high current wire:- (4 AWG)

Oh and for the electrodes:- (2.5mm)

Awesome thank you! However, I am not sure how to wire it up though I can read up on that later. I am confused as to how I would activate the switch as yours seems to have a push button. Could I somehow rig a foot pedal switch to it?

Yes, replace the button with a foot pedal from a sewing machine perhaps.

The wiring is very easy, I explain it in the video :slight_smile:

Awesome I have no experience with these types of switches or anything so even that simple wiring doesn’t make a ton of sense to me :grin:. I am confused as to how I would rig up a foot switch like this one. I am also a bit confused as to the placement of the wires on the solenoid. How do I know where each wire goes on it?

Thanks for putting up with me by the way :slight_smile:.

This is all it is…

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Im assuming that the 1V is supposed to be the 12v for the car battery? Also I am still not sure how I am going to know how to connect the wires not eps solenoid switch itself, like how can I tell the terminals apart? And if i am looking at this right the foot switch is connected to the solenoid switch and not the battery right?

Yeah that should be 12v not 1v.

The switch should come with instructions. That particular one is a double pole switch which means when you change the polarity it will switch to either set of main terminals. It’s not as simple as the original ATV one unfortunately but it can handle many more Amps.

Shit, my diagram is wrong, you’re right the foot switch doesn’t go like that, sorry for confusing you even more!

Hang on, I’ll do a new diagram…

Here you go, this is correct…

I am still unsure as to how to tel the terminals apart on the solenoid switch but I think Ihave asked enough questions for this thread, thanks for all your help!