I am not willing to spend hours seeing how long my battery lasts, but my impression is that my original N800 battery is not lasting as long, and here's a warning for those of you trying to decide on whether to buy cheap Hong Kong knockoffs or authentic Nokia batteries -- my genuine Nokia battery seems to be deteriorating faster than the knockoffs. So, please, don't take a chance when buying a battery -- in the interest of safety, buy disreputable knockoffs!