Sure thing, grab the old batteries, strip off the casing, and just solder the terminals to a cheap USB breakout board. Hook that up to a little 3.7V Li‑ion charger circuit and bam—your own DIY power bank. Or if you’re feeling dramatic, repurpose a broken phone charger, swap the cable for a USB-C, and you’ve got a portable juice box for your future zombie apocalypse. Just keep an eye on the voltage, don’t let it overheat, and you’re golden.

Got it, we’ll keep the temp in check, stick to a 2A charger board, and eyeball the voltage. If it starts a smoke show, out it goes—no fuss, no paperwork. Let's keep it quick, keep it safe.