OK. Others have told me that it is a purely mechanical problem of a circuit break somewhere/how during use in movement. Indeed, it worked spot-on all last night too, so I'll have to make a case myself to protect it while in use.

Hi Alex & all. This works really well. In just over 35 minutes in WIN10, I've just expanded 49 files of triggered recordings in audio files up to almost 20 min in length and which at max size weigh in at almost 1GB each. Yesterday, I tried expanding some other files and ran out of destination disk space, but it expanded the rest successfully until reaching the limit and then gave me a message saying there was an error for the last 6 files (so warning me of the limit). Hope it works as successfully in other OSs. Cheers, J

Thanks Alex. I have just done this, though I do see that it is now working, but incredibly slowly, even for very small files, so the memory issue would indeed seem to be the case. Thanks in advance. J

Hi Alex Is this just me? I still can't get it to work :-( J

Hi Alex. Well, I can't seem to find a way to get it to work. FYI, I've uninstalled and reinstalled the Config App, updated WIN10 and it still does the same, whether expanded on/to the microSD or when copied on the desktop, or even for new files from last night. I had brought the file length down anyway in order for it not to exceeed the 1 GB limit for uploading to Arbimon. I'll have to reduce the file length down to 20min and see what happens. I prefer to try and record everything, from birds and amphibians to orthoptera to bats, so really need all frequencies (up to 250k sampling rate in the vague hope I might get a smaller Rhinolophus sp one day). Even if 'just' batting, the local Tadarida drop down to 9 kHz on occasions so the high-pass filter would have to be set pretty low anyway! I'll try to do some bat only tests tonight on one AM to see what happens. Regards, John

Yes. I've opened several without issue so far and since there's a less than 3s loss for each half hour (I'm now recording 20 mins instead, so perhaps this won't repeat; I'll find out tomorrow I hope), it's not an issue. Regards, J

Hi Alex To answer in a different order: No, still not working. Just tried one file to the hard disk and it reaches the same stage but no temporary file visible in the destination folder (unlike on the microSD card those times it did work previously). Yes, enough space. I only tried expanding half of the files to ensure that there was enough space (19GB needed and 26.9GB available). I've done this before, deleting the T files before embarking on the next set. CONFIG file contents: Device ID : 242A26046037B5A4 Firmware : AudioMoth-Firmware-Basic (1.5.0) Time zone : UTC Sample rate (Hz) : 250000 Gain : Medium Sleep duration (s) : 0 Recording duration (s) : 1800 Active recording periods : 2 Recording period 1 : 00:00 - 05:00 (UTC) Recording period 2 : 19:30 - 24:00 (UTC) Earliest recording time : ---------- --:--:-- Latest recording time : ---------- --:--:-- Filter : - Amplitude threshold : 512 Minimum threshold duration (s) : - Enable LED : Yes Enable low-voltage cutoff : No Enable battery level indication : Yes Always require acoustic chime : No Just tried again, without success, and it goes first to "Starting to expand files" then to the second screen of "Expanding files..." [FILENAME underneath]. It also doesn't work with the Event based tab option either, which I've just tried, just in case... Odd! Thanks, J

@Alex Rogers None. Just to confirm that it was a battery issue. Even though the configuration interface suggested it has sufficient voltage, they were clearly on their last legs and now I've put some brand new rechargeables in, it's come back to life 100% (indeed without showing any change in voltage despite an entire night's recording). Looking forward to deploying another I acquired during the last round and also a third I am going to attach an external mic to for NOCMIG, which apparently works well and I just need to learn how to solder and learn some very basic electronics... Thanks to all again.

Alex. Well, you've nailed it and so my sincere thanks. It's been the second case, with file names but nothing else. A write error, but I'm now convinced due to very low battery power, rendering it simply unable to write to the card, despite maintaining the internal clock, etc. And very embarrassingly for me, you're right about the Energizer Ultimate Lithium batteries. Which undoubtedly explains the increasing problems I've had with them, even though when in the recharger (as I could have sworn they were rechargeable), they do seem to have recovered some of their charge. I'm probably lucky not to have provoked a fire! My sincere apologies for wasting everyone's time (though just should the problem persist - tomorrow I receive more rechargeable batteries - I'll certainly be back in touch). Kind regards, John

OK. I've tried a couple of tests using two short record / stop cycles with two different microSD cards, having brought the AM back indoors after supposedly recording last night (which failed completely; all blank files from start to finish). However, I switched it to default just before taking the card out and it recorded successfully for c. 10s (I didn't try longer). I tried the first test with 55s recording + 5s rest (empty files) over 5 cycles, with all files appearing and all empty. This despite it swtiching on OK and apparently recording with a red flashing light, before switching to dual red-green flashes. I tried a quick test immediately afterwards by switching to Default, which failed. I then tried another test with the same record/sleep cycle on a second card and it failed again. This time it barely came up with flashig red light to indicate recording, rather remaining almsot constantly on the dual red and green simultaneously flashing lights). So I'm assuming that it just doesn't have enough power. Having seen that they were recommended, I bought a pack of Energizer Ultimate Lithium batteries at the beginning, which I assume are genuine, off Amazon, though they come with no mAh rating either on them or on the external packaging (odd, since I've read -goodness knows where on the web- that they're rated either as 2600 mAh or 2000 mAh. And they worked perfectly at the start, with the AM saying they were at >4,9V. After a very few recharging cycles though, it could be that they're become useless for the job, AND/OR my recharger isn't doing it's job either. Would it make sense that it saves file names and is triggered at the correct times, but leaves the files completely empty due to insufficient power? This is very frustrating! Many thanks in advance for any further suggestions / comments. John

Michael. Many thanks for the reply. As noted above I have been using good quality cards from the beginning, but will try including some longer gaps in the cycle to see if that works. Kind regards, J

Hi Russ. Many thanks. I'll try it. Previously though, as I've been using 64GB SanDisk Extreme cards since the beginning, I was losing just 1s between the recordings even with this 0s rest setting, so I can't see why they now won't work as well. Since I view on Audacity, with my own parameters set up (30s spectrogram on the screen), and I dislike having to open lots of files (!), plus I am using Arbimon to upload to for later analyses (which won't accept files over 1GB in size), then I'm sticking to 30 min for the moment to see if I can work out the issue. Thanks again, J

Hello. I'm new to Audiomoth use but have experienced what appears to be the same problem after just a couple of weeks of use. With brand new batteries and unformatted microSD cards at the start, I had no problems, but with the recharger now leaving the (supposedly very good) batteries at say 4.6V starting value (rather than >4.9V), I'm now getting very varied results for the files. They start recording fine, but at some point simply stop, so I either get the full recording period saved (FYI, it's set at 1800s with 0s between from around dusk until just after dawn and low battery cut-off is disabled), or file stamps for the right cycle times (every half hour), but which contain no data. This is in contrast to the very beginning when I used some old rechargeable batteries for practice and found that they would record part of the files until the power dropped to low and then start again (for progressively recording time for each recording cycle) until the overall power got to low. So this is different (as it's all or nothing within each file). I have also reformatted the cards on Windows 10 as well though, and wonder if somehow it could have had an effect? If you discovered what the problem was, I'd be very interested to hear it, and thanks in advance! John