Specifications: Type: Li-ion Voltage: 21.6V Capacity: 5000mAh Replacement Part: Dyson: SV11, 164527-01, 214730-01, 215866, 968670-02, 968670-03 Compatible Models: Dyson: V7 motorhead, Dyson V7 trigger, Dyson V7 animal, Dyson V7 car+boat, Dyson V7 absolute, Dyson V7 HEPA, V7 Dyson Extra, V7 Mattress, V7 FLUFFY, Dyson SV11 Announcements: Please don't store the batteries for a long time, it need to be used at least once a month. If it's necessary, please using a cotton swab with alcohol to clean the battery and the charger metal contacts. After long-time using in your power tools, please fully rest the batteries. Before recharging the batteries, please make sure that the batteries have already cooled down.