Hi I have a Mavic pro and one of the batteries is an after market battery' and after about 14 or 15 flights with this battery it came lose and disconnected from the drone inflight' but it happened close to take off so I found the drone and the battery after looking for about 20 min. So anyone using an after market battery keep a close eye on the little plastic clips where it locks on the drone they wear and the battery falls off the drone.