Xtend Battery for 9 Cell Battery for Dell Studio XPS 16 1640 1640n 1645 1645n 1647 1647n laptop Battery type: Li-ion; Capacity: 87Wh; Cells:9-cell; Voltage: 11.1V;Capacity:7800mah. High quality grade "A" cells. Charges quickly. Longer discharge time. Steady output and low power consumption. More than 500 times charge-discharge cycles.All products are Certified by CE ROHS UL1642 FCC for safety. Operation time for standard batteries(9-cell 7800mah): Around 2-3 hours the actual operation time will depend on how much electricity is required by the device and how you use it. 24 x 7 email support 12-month service. Compatible Models: For DELL Studio 16 Laptop Studio XPS 1645 Studio XPS 16 Studio XPS 16(1647) Studio XPS 16(1645) Studio XPS 1640 Studio XPS 1647 312-0814 U011C W298C X411C 312-0815 451-10692 W303C PP35L replacement notebook laptop battery batteries 12-months hassle-free warranty service. Please check if this battery is compatible with your computer before purchasing. Part numbers of compatible batteries and Computers are listed as following.