Powerall is supposedly one of the top brands in this market and because of that it is also one of the most copied/counterfeit.
Strangely for a Yank company their specs are very vague but, pfft, thats life these days.
If that one is a knockoff they went to great lengths to make it look genuine.
So lets assume it is genuine...then... you could maybe flick Powerall an email query or try and see if their online warranty rego will accept the device.
Like I said before I'm not convinced yours is bad just curious and if it still works then who cares anyway right?