Best battery + microSD setup for long-term AudioMoth recordings at 48 kHz?
Hello everyone,
I would like to ask, based on your experience, what is the best microSD + battery setup to achieve the longest possible autonomy with AudioMoth.
I used:
- Energizer Ultimate Lithium AA batteries
- SanDisk Extreme 128 GB microSD card
Configuration:
- recording at 48 kHz
- about 8 hours per day
For the first 8 days, the AudioMoth recorded perfectly, producing about 2.42 GB of audio per day.
Starting from day 9, however, it began recording progressively smaller files:
- ~500 MB
- then ~17 MB
- then only a few MB (2–3 MB)
- finally around 1 MB
The files were not corrupted: they were valid WAV files, but only a few minutes long.
There were still more than 100 GB free on the card, so I do not think this was a storage space issue. I also tested the batteries with a battery tester and they still appear to be almost full, but I suspect that under load the AudioMoth may require current peaks that the batteries can no longer sustain.
In your opinion:
- is this actually a power supply/battery issue?
- which combination of batteries and microSD cards has given you the best results for long recordings at 48 kHz?
- do you use external power banks or other specific setups?
Thank you very much!
This thread has been very helpful for me, as I am experiencing the same failed recording problem as OP with AudioMoths, paired with 128GB Sandisk Extreme usd cards and Energizer AA lithium ultimate batteries, used in my CA statewide monitoring program. Battery voltage records show that I'm running out of power part way through recording periods, consistent with the issue outlined above. There is one more piece of the puzzle that I can not yet explain, outlined below.
We are using bird recording protocols developed by partners at the California Department of Fish and Wildlife (CDFW). Those partners have been using the same schedule (two recording periods per day--00:00 to 09:00 then 20:00 to 23:59--for 7 consecutive days) with 128GB Sandisk Extremes for years with no problems. When we adopted these protocols, we almost immediately started experiencing failed deployments, mixed with some successes. We've used AudioMoths with firmware versions 1.11.0 and 1.11.1. All 1.11.1 deployments have failed, and some 1.11.0 deployments have failed and some succeeded.
Alex, can you think of anything that could explain this discrepancy? Do different firmware versions cause different battery drain with the same sd cards?
Thanks for your help. I appreciate your responsiveness on this forum.