I seen so many of these that were battery powered. I didn't want one like that, because I'm not using it on the go. I'm sitting in one place using it, so I wanted one that plugged in so I knew it would always have the power I needed.
With that said. Idk if it's like this with other ones but it was to charge up before you can use it. It takes like about 20mins the first time you use it. If you use it daily it won't be that long. But it has to be above 5v to spot weld.
Then you better know how thick your nickel strips are. So you get a good weld. If it's turned up to much. You'll burn right through like nothing. So it is powerful.
Bioelectrik 
