Actually it's interesting. I think it might be a good opportunity to think about how we can transition to rechargeable batteries in the field. Shipping them is possible if you follow postal rules and pay for hazardous material charges. But it needs to be planned in advance. Anyways, might be a good conversation to have in the community. But there also needs to be other foundational work like understanding how they're used, getting chargers in the field, and how to interface rechargeables to standard equipment.

We've been using 18650 lithium ion protected cells in our BAR recorders since 2013. The protected cells are great because the protection circuitry kicks in to disconnect the battery and save it from being dicharged too much. It also protects against short circuit.

So if you did want to give 18650 batteries a try then I'd recommend a Keystone 1043P (P for polarised so you can only fit the battery one way)  battery holder and KeepPower protected 18650. There are a few other brands too that fit that battery holder ok but that's a common consistent brand.

Eizfan and XTAR make good chargers.

Most of our customers use them in the same continent and drive or road freight their recorders to site and so don' thave any problems shipping them.

We've heard of some problems on planes taking them as hand luggage and it's just luck of the draw if the particular person you encounter in the baggage area knows what their lithium ion battery policy is. I've usually heard of I think attempts to get this claried at the airline level has lead to a run around too.

Some people get to check them in if the batteries are fitted into the battery holders because they consider it built in like a phone or laptop. The spare batteries often go on as hand luggage. We have plastic battery cases to hold the cells for travel.

If you're sending it overseas we find that DHL, UPS and Fdex seem to take about a month to get the paperwork sorted out to give you permission on your account to ship lithium ion batteries with your recorders. Once you have permission though you can do it whenever you need to in the future for subsequenct studies. Look up the IATA regulations for packing lithium ion batteries with your equipment. You'll need to know this so you can tell DHL etc what permission you need and what you typically do. We use UN3481 packing instruction 966 section II becasue our cells are <20Wh and we can ship 5kg of batteries in a carton along with our recorders.

https://www.iata.org/en/publications/newsletters/iata-knowledge-hub/what-to-know-about-how-to-ship-lithium-batteries/

Mark Calder

Frontier Labs www.frontierlabs.com.au

Wanted to chime with another option. My lab develops OpenSoundscape, a Python software package for training machine learning models for bioacoustic detection, especially convolutional neural networks. Check it out at http://opensoundscape.org/

I see that the list of bioacoustic softwares was mentioned earlier in the thread (thanks Carly!) - I'm always on the lookout for new softwares to add to that, so drop me a line if you see a package that is currently maintained and relevant to bioacoustics but is not included on the list. 
(Here's the link: https://github.com/rhine3/audiomoth-guide/blob/master/resources/analysis-software.md)

Hi Nicole--

We've already chatted about this function, and I think the answer is "quite a bit" for a lot of deployments. The more accurately the proposed function tracked microphone status the better, though even something to the effect of "I'm still getting a signal from this microphone" even if there was no more nuanced quality information than a yes/no would still be better than what much of the field is doing right now. 

I think the question is how much this would add to the cost of the unit + how much whatever data service you're using would add to the ongoing costs but I'd imagine that Frontier are still figuring out those specifics.

Almost a year since the original post, but just commenting that I've been having some pretty good success with BirdNET which has been working fine in the past few weeks I've been using it.

Dear Thomas I'm really interested by your experience, how did you use birdnet?

I would like to monitor a area for a certain amount of time with birdnet automatically identifying the bird around, is it possible to do that? Or did you record a sound bird for a while, then transfer the audio file into bird net and manually identify each bird sound?

All the best, Antoine

Tessa Rhinehart has developed a great compilation of bioacoustic analysis platforms, software, etc. with basic functionality on each. It's openly-available on Github -https://github.com/rhine3/audiomoth-guide/blob/master/resources/analysis-software.md. 

I personally use RavenPro (from the Cornell Lab of Ornithology), Kaleidoscope (from Wildlife Acoustics), and Arbimon (from Rainforest Connection) in different capacities. I've also heard good things about PAMguard (developed firstly in the marine mammal community) and Sonic Visualizer.