Portable illumination
Rules:
Related:
I made my own out of a motorcycle battery (which I have lying around in abundance), a length of jumper cable, a starter relay off of I think a 50cc scooter with a random salvaged microswitch as the trigger, and two short lengths of sharpened 10 gauge Romex as the probes. It works a treat. I haven't fried a single 18650 with it yet.
I think my total net bill of materials was about $12, not including the junk I already had lying around, the majority of which was the relay.
Interesting. I don't have a motorcycle battery around but I do have one of those lithium portable jump starters. I wonder if that could work.
In theory, yes. But those usually have electronics in them in an attempt to save you from yourself. So it's unlikely that the thing would fire when you wanted it to without being fooled into believing it was hooked up to a 12v battery in some way.
You can get off brand motorcycle batteries online for like $20. The quality is irrelevant for this application, especially since you probably won't be welding hundreds of battery tabs in a day. The point is that they can reliably deliver enough amperage to weld the tabs while having a low enough terminal voltage to be unlikely to deal either yourself or your cells a mischief.
Fair enough. Jump starters often have an override button so they'll still operate when the car battery is at 0V, but IDK how it works.
It's worth a try.
Maybe later I'll post a picture of my gimcrack contraption.