The fujifilm np-50 lithium-ion battery pack is a proprietary camera battery with a 1000mah normal battery capacity and a 4.2v charge voltage. it works both with the bc-50b battery charger and third-party chargers.
the np-50 is compatible with the following fujifilm cameras: x20, x10, xf1, finepix f900exr, finepix f850exr, finepix f800exr, finepix f770exr, finepix f750exr, finepix f660exr, finepix f600exr, finepix f605exr, finepix f550exr, finepix f505exr, finepix f500exr, finepix f300exr, finepix f200exr, finepix f70exr, finepix f100fd, finepix f60fd, finepix f50fd, finepix xp200, finepix xp170, finepix xp150, and finepix xp100.