UBatteries Laptop Battery Sony VAIO VGN-Z799DJB VGN-Z820D VGN-Z820D/B VGN-Z820G VGN-Z820G/B - 6 Cell, 4400mAh (Silver) UBatteries Li-Ion Replacement Laptop Battery; Grade A Cell Type: 6 Cell Lithium-Ion | Voltage: 10.8V | Capacity: 4400mAh | Rating: 48Whr CE ROHS Certified One Year Warranty, 30 Days Return