I purchased one of these replacement batteries when one of the original two went bad and suddenly would not charge any longer. I hadn't even owned the A10 Hero Stick Vacuum for 10 months when it stopped charging. Under warranty I was able to get a replacement to for the bad one. Initially it worked fine, but now either the remaining original battery or the replacement has stopped charging. These batteries are very expensive and they made me jump-through-hoops to prove it fails to charge; I had to photograph the charger's label side and also provide a video of me plugging in the failed battery showing the flashing LEDs and up load both files. I had to redo the video at a very low resolution as the file size was not accepted and rejected as too large by their system. Support eventually did send me a new battery, but now I think that one has failed too; same suddenly not charging any longer! I own an Tineco A11 Hero EX stick vacuum at another residence that I purchased in May 202 with which I have hand no issues! That model has batteries that have an integral charging connector built into the wall mount stand and the both batteries have worked great without any problems. This Tineco A10 Hero model has this lame wall charger that you have to plug into the side of the battery. My solution to these failure problems of their expensive batteries is to research and find another Stick Vacuum made by a more reliable company!