Puredick&reg; High Performance New Laptop Battery for Dell Inspiron 14R Series N3421 N5421 Inspiron 5437, Dell Inspiron 15 Series (3521, 5521, 5537), Dell Inspiron 17 Series (3721, 3737, 5721, 5737), Latitude 3440, Latitude 3540, Vostro 2421, Vostro 2521 - 12 Months Warranty [Li-ion 6-cell 11.1V 5200MAH/58Wh] Battery Type: Li-ion || Voltage: 11.1V || Capacity: 5200/58Wh|| Color: Black||Cells: 6-cell 100% New from Manufacturer. Up to 500 recharge cycles over the life of the battery. Grade A cells ensure fast charges and low power consumption; Built-in circuit protection ensures both safety and stability. CE-/FCC-/RoHS certificated for safety,12 months warranty,professional technical support, efficient and always satisfied customer service 24 x 7 email support. Operation time:Same Battery life with Brand new original Dell battery.In reality, this will depend on the amount of electricity required by the device and how you use it