2-Pack Powerextra 22.2V as the Original Handheld Vacuum Cleaner Battery for Dyson DC31 Compatible Part Number 917083-01 More favorable than 1-pack! Li-ion battery,2000mAh Capacity,22.2V,made with high quality battery cells Fully compatible with your power tools, WILL NOT VOID your manufacturer warranty No memory effect. Can be charged or discharged as needed without loss of capacity. Batteries are made with the LG 18650 Cells. 30 Days Money Back 12 Months Limited Guarantee!