CSE New Laptop Battery [Li-ion 9-cell 7800mAh/87Wh] for Dell Inspiron 1520 1521 1720 1721 Vostro 1500 1700 Series Pn 312-0504 312-0513 312-0518 312-0520 - 12 Months Warranty Battery type: Li-ion; Capacity: 7800mAh/87WH; Cells: 9-cell; Voltage: 11.1V. 100% New from Manufacturer. Up to 500 recharge cycles over the life of the battery. CE-/FCC-/RoHS-Certified for safety. 24 x 7 email support,12-month hassle-free warranty. Grade A cells ensure fast charges and low power consumption; Built-in circuit protection ensures both safety and stability. Operation time: the actual operation time will depend on how much electricity is required by the device and how you use it.