2 DIY Battery Gadgets

2 battery gadgets,one of them is how you can charge the battery with dead batteries if you connect 5 dead batteries in serial.
Second easy and simple gadget is that you can make foam cutter
from 2 metal keys and wire.

music by teknoaxe
track:Vacation in the Cryptosphere – Synthwave
youtube link:https://www.youtube.com/watch?v=GrEwfdy5k7Y