What is this electrical device?

[Kens1990K2500]

If plan on replacing it I would find out what it is first. But it kind of looks like a positive Junction box. But to see if that is true test with an ohm tester to find out if any juice is going through there

Will do, thanks for the suggestion.

 

[Hpilot]

Looks like a circuit breaker that was used in the older battery chargers. In case you got the charger wires crossed, it would then reset once the conditions (proper polarity) was correct. Eventually it would fail and your charger stopped working. At least that’s my opinion, I maybe wrong.