Specifications Hign-concerned Chemical:None Nominal Capacity:4000mAh Size:Prismatic Model Number:Dyson V7 Battery Type:Li-Ion Origin:Mainland China Certification:CE,KC Replacement and Compatible Battery Models Compatible models: V7 FLASH, V7 Extra , V7 Mattress, V7 Trigger V7, V7 Motrhead Pro, V7 Tier, V7 Car Product attributes: 1. intelligent program protection prevents from over charge 2. high quality replacement battery 3. compatibility with the 4. lower price than OEM battery 5. no storage effect. 6. voltage: 21,6 v 7. capacity: 4000mAh 8.Battery Type: Li-Ion Battery advantages: 1.BEST PERFORMANCE and PERFECT COMPATIBILITY: Fully compatible with the charger and vacuum cleaner. it is easy to install. 2.TRUSTWORTHY RELIABILITY: No storage effect, Low rate of self-discharge (1% per month). Patented battery balancing technology, Built-in over protection circuits provide safety and reliability from fire and explosion. 3.GREAT SAFETY: Quality Li-ion battery cells with CE and UL approval. it imports from Japan, quality guaranteed. 4. Advanced Li-Ion technology provides improved energy density. 5.STRONG GUARANTEE:7 days money back,1 year limited warranty seller against manufacturer defective from purchase date. Warm notes: 1. Please fully charged battery before first use. 2. If you are not willing to use the battery for a month or more, shop it in a clean, dry, cool place away from fire and water. 3. please charge it after long storage. As Ni-Cd Ni-Mh and Li-Ion batteries is self-discharge during storage. 4. not separation, extrusion, and impacts. 5. if the item is defective, please notify us within 7 days after receiving it. 6. As a rule, We will send the items within 2-3 working days as soon as their payment is completed. As a rule, after we ship, the express system takes 7-10 working days to update tracking None. to the system. ONE usually, the package can be delivered in 6 weeks. If you do not receive your package in time, please kindly advise us, we will send the package. Note: Please use max gearbox for more than one minute.