Review on High Performance 4.0Ah KUNLUN V7 Replacement Battery Compatible With SV11, V7 Absolute, Motorhead, Fluffy, Trigger, HEPA, Car+Boat Vacuum Cleaners - Includes Bonus Filter & Brush by Mark Greenwood

My big dyson vacuum broke, and then I tried to use my backup mini dyson v7. I noticed that the batteries were totally dead, and when they're dead for a while, it gets damaged and irreparable. My bad, u need to keep the batteries charged all the time BUT do not charge if the battery is hot after use, (put palm to check no big deal) AND do NOT use the MAX option for every time u use it. use it on very special occasions (safety) like vacuuming glass. but if u excessively use it on "max" u WILL damage the batteries. not maybe, batteries get damaged like that. they're not original so make ur money worth it and take care of it.