I've been using Eneloop LSD NiMH rechargeables without problem. The voltage may be only just above what is required but it remains very constant. Apart from having to buy and dispose of many primary cells I can always put a set in the device knowing it is fully charged. If primary cells are used their capacity will be unknown unless a new set is used for every session. Will the Audiomoth 2 voltage booster work from 2.4V?

Yes I'm using Eneloop low self discharge NiMH cells in my device. The voltage seems to be steady at 3.9volts after it drops from an initial 4.4volts. It seems to work fine. As I've not used non rechargeable cells I don't know how they compare. Their capacity is nominally 1900mA hours. Unfortunately I don't know if they were completely charged when I inserted them, but from my limited experience in using them I should think that might be the capacity figure to use. One advantage of rechargeable cells is that they can always be inserted fully charged! They certainly appear fine for my use to date. Mike

Fran Note Alasdair's comments that these are not commercial products, so BTO or NHBS would have to sell them as such. They might not want to do that. I have one from the last round and am just trying it out at the moment. If you are interested in recording bird song, then from my limited experience these devices seem to work very well. I didn't buy it for that purpose, but am using the dawn chorus as a test. I have now ordered another device! Regards Mike

It's a very good summary even if you're not in the field. Perhaps needs to be on the AudioMoth website. As regards "What do the LEDs tell you" I think "With Switch set to USB/OFF" should be amended to "When the Switch is moved to USB/OFF". This maybe a minor point, but would be more helpful to someone using the device for the first time.

I am just trying out my audio moth and the same thought occurred to me. I don't think hard coding into firmware is the route to go even if it easy to do. I'm not a programmer so wouldn't be able to do that, not unless it could be easily explained. Also once fixed in the firmware there is the problem of resetting the configuration if required to do so. Mike

Even better value here http://www.picstop.co.uk/microsd-sdhc/sandisk-extreme-microsdhc-100mbs-a1-c10-v30-uhs-i-u3-32gb.html