Specifications High-concerned chemical:None Size:18650 Set Type:Batteries Only Type:Li-Ion Nominal Capacity:>3500mAh Model Number:for dyson dc31B Brand Name:bonacell Origin:Mainland China Certification:CE,FCC,RoHS The replacement battery is for Dyson DC31B, NOT fit DC31 type A, please check the connector of your battery before purchase Works for Dyson Handheld Vacuum Cleaner DC31, DC31 Animal, DC31 Animal Exclusive Dyson DC34 DC44 (Not Fit Type A, DC44 MK2) If you don't plan on using the Power Tool Battery for a month or more, store it in a clean, dry and cool place away from heat and metal objects. Ni-Cd, Ni-MH and Li-ion batteries will self-discharge during storage; remember to recharge the batteries before use. Made of lead-free SMT process,fit with the requirements of environmental protection No memory effect. Can be charged or discharged as needed without loss of capacity. Fit Machine Models: for Dyson Handheld Vacuum Cleaner DC31, DC31 Animal, DC31 Animal Exclusive for Dyson DC34 DC44 (Not Fit Type A, DC44 MK2) NOTE: NOT fit Type A series models, please check your battery type Battery Maintenance 1. Always remove battery pack form your tool when you are assembling parts, making adjustments, cleaning or when not being used for an extended time. 2. If you don't plan on using the Power Tool Battery for a month or more, store it in a clean, dry, cool place away from heat and metal objects. Ni-Cd, Ni-MH and Li-ion batteries will self-discharge during storage; remember to recharge the batteries before use. 3. Do not leave the battery dormant for long periods of time. We recommend using the battery at least once every two to three weeks.