ZTHY Compatible C22-UX31 Replacement Laptop Battery for Asus ZenBook UX31 UX31A UX31E UX31A-R4004H UX31E-DH72 UX31KI3517A C23-UX31 Ultrabook 4-Cell 7.4V 6840mAh/50Wh Voltage: 7.4V. Capacity: 6840mAh / 50WH. Battery type: Li-polymer. New from Manufacturer. Up to 500 recharge cycles over the life of the battery. Safe battery: CE-/FCC-/RoHS Certificates are tested by reputable,qualified and accredited testing laboratories,ensures superior performance,quality and safety. Replace part number: C21-UX31 C22-UX31 C23-UX31. Fit For: Asus (Zenbook) UX31A UX31E UX31 UX31A-R4004H UX31E-DH72 UX31KI3517A Ultrabook Series Laptop Superior quality: strict guidelines for compatibility,4 grade A cells, high capacity and low power consumption, built-in circuit protection, avoid over-voltage, over-current and over-temperature, meet with environmental and safety requirement Warranty: 12 Months Warranty, 30 days money back guarantee. With Hassle-free Customer Service