BRTONG NewLaptop Battery [Li-ion 9-cell 7800mAh/87WH] for DELL Studio 17 Series 1735 1737 Series laptop battery: KM973 KM974 MT335 PW823 RM868 RM791 KM976 RM870 RM791 KM978 PW824 series 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 for standard batteries(6-cell, 4400mah): Around 2 hours, the actual operation time will depend on how much electricity is required by the device and how you use it.