Lenmar Replacement Battery for Sony VGN-FW Series Laptop Computers 11.1V / 4800mAh Lithium Ion fits Sony VAIO Series VGN-AW41MF, VGN-AW51, VGN-AW80, VGN-AW90, VGN-BZAA, VGN-CS11, VGN-CS13, VGN-CS16T, VGN-CS190, VGN-CS290, VGN-CS36, VGN-CS60, VGN-CS90, VGN-FW21, VGN-FW25, VGN-FW340, VGN-FW37, VGN-FW51, VGN-FW82, VGN-NS50, VGN-NS51, VGN-NW320F/TC, VGN-NW320F/TC, VGN-NW380F/T, VPCCW1EFX/W, VPCCW1S1E, VPCCW2S1, VPCY218EC/L. Replaces: Sony VGP-BPS13/S, VGP-BPS13A/S, VGP-BPS13AS, VGP-BPS13B/S, VGP-BPS13S, VGP-BPS21, VGP-BPS21A. Note: You will be required to install a non-hazardous program to ensure the battery will be 100% compatible with your laptop. This program will update the underlying device driver of intelligent lithium battery, including the BIOS. Please read the instruction manual carefully before you start to install the program. This BIOS update is not compatible with machines that have been upgraded to Windows 7 64-bit, from an original 32-bit machine.