Of course, it is not original and I would not trust a component as critical as the battery in any brand other than the original from the manufacturer for safety reasons.
Firefox is no longer an adversary to Google for the browser market, if it ever was. FF has become a vassal of Google that with its tyranny is dictating the course of the internet, such as WEI that as far as I know it was abandoned at least for now.
Of course, it is not original and I would not trust a component as critical as the battery in any brand other than the original from the manufacturer for safety reasons.