Hey there my name is John this is a same thread at forumdji. I'm currently having possible issue with my battery that was recently sent by DJI as a replacement which was obviously used and possibly damaged. It was charged 7 times and had a 31 history. HISTORY My history with the battery started since sept 7 when one of the battery which was used maybe 1-2 times had this metal prong protruding on the teeth/cartridge/connector whatever you call it. Because of this metal protruding it was difficult for me to insert it in my P4 or the charger. After the long process on DJI support it was sent to DJI north america. They replaced it with a used battery (instead of a new one even though i was on warranty and the battery was 14 days old and was used a few times) as stated above. It took them 1 month to replace the damaged battery. ISSUE So i got this battery 082AD1F03102ZY. A used battery with visible scratches, lots of bended plastic at the left side outer plastic(possibly from a crash?) Because of the said condition I decided not to use it till i try it. Flew the P4 for 10 mins in a steady state 5-10 feet stationary with no problem. I was relieved after that. I decided to just land it, remove the propellers and keep the P4 on while i play around with the controller, when suddenly the critically low voltage warning came up even though I still had like 28% battery and battery is not too warm or too cold. Kept the P4 on while writing this thread when another error popped out air encorder error (0x20). This is the first time this came up for me, tried the other battery but the air encoder error doesn't came up. Can anyone give me advise on what to do with this? My honeymoon is almost up on november 8 and I really needed a 3rd battery. I was planning to just buy a new battery and then get a reimbursement because if I waited for DJI it will take another month and consume my time/effort sending them pictures videos etc. In case they don't replace the battery I will just post on all social media and warn them about DJI's customer service, "is it worth to get the mavic? become the beta tester, and experience the worst customer service" I'll just honestly tell them my experience. Ill try to provide some pictures soon.