He’s using an armature growler (YouTube link) to test the armature from a generator. Armature growlers (or just growlers for short) were commonplace years ago. Back when cars had generators ...

When extreme weather, power surges, or grid-wide maintenance cuts you off, having a backup generator can be a lifesaver ...

If you're looking for ways to keep the power at home on during outages, a whole home generator might be a fit. But knowing which one is right for you is dependent on your home and your needs.