Spot welding question.

[Brian Ski]

Seen a video the other day of someone spot welding tabs on Nicad batteries to put them in a battery pack. Is there any way to make a welder into a spot welder??? I have a 200DX TIG All I could see in the video was they had 2 insulated copper rods the size of a pencil that they would make the spot welds with. I am guessing using a foot pedal. Maybe the TIG with custom leads.

Ideas where to start. Might be able to dig up some copper rods and get a couple extra cables for the 200DX. AC or DC polarity???

[Rambozo]

Seen a video the other day of someone spot welding tabs on Nicad batteries to put them in a battery pack. Is there any way to make a welder into a spot welder??? I have a 200DX TIG All I could see in the video was they had 2 insulated copper rods the size of a pencil that they would make the spot welds with. I am guessing using a foot pedal. Maybe the TIG with custom leads.

Ideas where to start. Might be able to dig up some copper rods and get a couple extra cables for the 200DX. AC or DC polarity???

Plenty of people have made them from microwave oven transformers, running AC, so that would work, not sure what the commercial units use. Having a spot timer would be ideal, but you could make that part up, yourself. Just connect it to the torch switch pins. You can find a bunch of how to guides on the web and places to buy the battery tabs. I have a stack of old batteries that I want to re-cell, so that project is also on my list. However, I am not sure I will ever get to it...

[Rambozo]

Looks like the current required is a bit more than what a normal TIG welder will do. Probably best just to make a complete unit.

http://www.avdweb.nl/tech-tips/spot-welder.html

Another option is to use DC and a capacitive discharge type welder. That you could charge with a TIG power supply, but that is overkill, and a much lower DC supply would do the job.

[Brian Ski]

Looks like the current required is a bit more than what a normal TIG welder will do. Probably best just to make a complete unit.

Not sure on his numbers... 1100 amps may be to spot weld thick metal.

I found this one on Ebay 221464732210 made for batteries. 100 amp max and for batteries it said about 25-29 amps. Still hate to drop $150 for something that may be used a few times.

A couple new battery packs are going to cost me $90 a pop. Depends on what I can get new batteries for. I found a place that had some brand new bastard battery packs for $3 a piece. (they fit some really odd stuff) I think they had a dozen new batteries in them. Pretty good price!!!

[Blaster]

Ya know,,, you don't have to spot weld them...

I routinely solder those tabs

[zoama]

Ya know,,, you don't have to spot weld them...

I routinely solder those tabs

I worry about putting too much heat into my batteries. What's your method ?

[Brian Ski]

Ya know,,, you don't have to spot weld them...

I routinely solder those tabs

Yea I have done that before. They are not as secure and if you use a wire to solder them they don't lay as flat. Plus you use a lower heat for a lot longer time. I never had a problem either, but heard they can explode. The Lithium ion batteries are a lot more dangerous to solder. When you are soldering a dozen batteries together, never fails I get a weak connection in one of them.

[zoama]

I'm curious about that myself. I have a bunch of 18650 li-ion cells I need to put tabs on.