Egoway Laptp Battery for Dell M6600 M6700 M4600 M4700 Workstation Precision Mobile Battery type: Li-Polymer battery; Voltage: 11.1V; Capacity: 7800mAh; 9Cell. Grade A cells ensure fast charges and low power consumption; Built-in circuit protection ensures both safety and stability. 100% New from Manufacturer. Up to 500 recharge cycles over the life of the battery; CE-/FCC-/RoHS-Certified for safety. Operation time for standard batteries(eg, 4400mah): Around 2 hours, the actual operation time will depend on how much electricity is required by the device and how you use it. Warranty: 18 - month warranty; 30 days money return guarantee; 24 x 7 email support.