Anyone recommend a cheap battery spot welder?

[Moley]

Anyone got any recommendations for a cheap battery spot welder. I'll only be doing a few every now and then so don't want to spend much on something that's going to spend a lot of it's life sat in a cupboard. It'll be around 6 x 18650 batteries about once/twice a month. I've been looking at something like THIS . It's cheap enough at around £28 but I've seen mixed reviews. Anyone got any experience of these things?

 

[timhoward]

I made one for a friend. It was basically a larger car battery, a 200A fuse, two copper nails, a 12v starter solenoid and a microcontroller to close the relay for extremely short measured periods of time ( < 40ms) when a switch was pressed.

However, taking the same principle, allowing lots of current to very briefly flow, there's an even simpler similar design here that is about as simple as it gets. I've also copied this chaps design and it does the job just fine.
All you need is a car battery, a starter solenoid, some old meter tails and some twin and earth. And a momentary switch.

 

[Moley]

Got to admit, you can't get much more minimalistic than that. I just watched another one of his vids and he seems to do a pretty good job too. If I had a workshop to work in I might consider going down that path but as I'm working on the dinning room table I might get complained at if I start chucking car batteries everywhere :-(

 

[Zimmerin]

DIY Arduino Battery Spot Welder Prebuilt Kit V4 - Malectrics

This Spot Welder can be used to weld 18650 batteries. It needs a 10-14V power source (12V recommended) and uses a 12V car battery as welding current supply.

malectrics.eu

 

[Moley]

That works out expensive by the time you add in the car battery, psu, cables etc. For the amount of use it would get it's not worth the expense.