Damn disposable vapes are a huge waste.
With proper matching, capacity testing and balancing, discarded electronics make great cell sources as long as one minds the charge/discharge rating.
I’ve built a couple powerbanks, charging systems for my remote mounted ADSB monitor, batteries for DIY speakers, added capacity to battery operated lights and more.
He goes into that a bit. He had to make a “balancing circuit” (basically just resistors between the batteries) to prevent the batteries from overheating when they’re first connected to each other.
Looks like it's about half bolt by weight to make sure all those spring connectors stay solid. Guy needs a battery welder or something.
I found a YouTube link in your post. Here are links to the same video on alternative frontends that protect your privacy:
