Puredick&reg; Laptop Battery for ASUS C21-EP101 Eee Pad Transformer TF101 TR101 Series -12 Months Warranty[Li-ion 2-cell 7.4V 3300mAh] Battery Type: Li-ion || Voltage: 7.4V || Capacity: 3300mAh || Cells: 2-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.