Hi everyone, Recently I retrieved 5 AM (model 1.2.0, firmware version 1.8.1) and found 4 cards were dead. All AM used alkaline dry batteries and 5 cards are 128G SanDisk microSDXC UHS-I. The AM with an unbroken card was the only one with power left when retrieved, and the other 4 AM ran out of power. Could this lead to the broken cards? Some information about setup and cards: I have enabled the "Enable low-voltage cut-off," and I assume this option is for Power failure protection. The computer can not detect those broken cards, as if I plugged an empty card reader into the computer. I have changed the card reader and computer (including Mac and Windows), but nothing worked. No physical damage is visible on the surface of these cards。 Has anyone anything to comment on this? I know sometimes the cards are just broken out for no reason, but 4 out of 5 are too much. I am worrying about the AMs I haven't retrieved. If anyone knows how to save the cards or avoid damage, I will be very grateful! Thanks a lot! Liufeng