Hi! I recently deployed 6 Audiomoth units at 3 different locations (2 audiomoths per location). They remained in place for almost two weeks, and were scheduled to record starting on the third day. Of these 6 audiomoths, only three seem to have recorded with no issues. One audiomoth stopped recording on the first night, and two audiomoths have no file saved to the sd card, no recordings nor config file. What's weird is that these two audiomoths with no recordings managed to drain all batterie charge, with the Config App reporting less than 3.6V. All audiomoths were "alive" when deployed, i.e. were flashing when set to Costum (though I do not recall the flashing pattern), but the two that did not record anything were not flashing when collected.

Looking for advice on what went wrong.

I'm detailing the materials used below, and attaching a config file, which was mostly the same for all devices, with half set up for recording from 00h to 12h and the other half from 12h to 00h. My guess is that the SD cards were at fault, since the two Kingston Canva Select Plus 512Gb used had no issues (100% rate of success), while only one of four PNY Elite 256 Gb performed with no issue (25% rate of success). Everything else was the same between audiomoths, both battery model and configuration.

PS: just noticed another concerning detail: The audiomoth was set to 9min:55s recording and 5s sleeping cycles with a 1s trigger. On the devices without recording issues, I'm noticing that there is a file for every 10 minute interval in the day, but almost all files are less than 10 minutes in duration. Does it only record after the trigger up to the end of the 10 minute interval? Or should all recordings be 10 minutes long (which would imply recording issues)?

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SD cards used:

• 2x Kingston Canvas Select Plus 512 Gb (https://www.kuantokusta.pt/p/1759210/kingston-512gb-microsdxc-canvas-select-plus-class10-uhs-i-adapter-sdcs2512gb)

• 4x PNY Elite 256 Gb (https://www.worten.pt/produtos/cartao-de-memoria-microsd-pny-elite-265-gb-6985174)

Batteries:

• 3 Engergizer Max Plus AA-LR6 1.5V Alkaline batteries per audiomoth. Same battery model for all devices used. All batteries where fresh from the package.

Recording results per audiomoth:

• A1 (Kingston): No issues, 4.1V charge, retained schedule information;

• A3 (Kingston): No issues, 4.2V charge, retained schedule information;

• A4 (PNY): Only one night of recording, 4.5V charge, retained schedule information;

• A5 (PNY): No issues, 4.1V charge, retained schedule information;

• A6 (PNY): No recordings nor config file, <3.6V charge, did not retain schedule information;

• A7 (PNY): No recordings nor config file, <3.6V charge, did not retain schedule information;

Config file attached