Power-wise, these warmers use a 18650 cell and a TP4056 charging ... requirements to quick but thorough explanations of nichrome wire and basic electronic theory. And then there’s the material ...

But [Matthias Wandel] may be on to something. Here he’s using nichrome wire to reinforce the broken plastic part. The repair process is demonstrated in full in the video after the break.

When a length of copper or nichrome is heated, it lengthens due to thermal expansion. The wire is suspended between two posts and heated by a variac. A small weighted hook is placed in the middle of ...