AudioMoth Battery & SD card buying guide
AudioMoth Family
Battery & SD card buying guide
What to actually buy, not how much you'll need for a specific deployment - for that, use the Battery & SD Card Calculator instead.
Short answer
Lithium AA batteries, plus a SanDisk Extreme U3 microSD card
That covers AudioMoth and HydroMoth. MicroMoth and AudioMoth Dev use a small Li-ion cell instead of AA batteries. Details for each below.
Batteries
AudioMoth & HydroMoth 3 × AA
All three common AA chemistries work. Which one to buy comes down to the deployment:
- Alkaline (about 2600 mAh) - the default. Cheap, available everywhere, fine for standard deployments.
- Lithium (about 3600 mAh, e.g. Energizer Ultimate Lithium) - roughly 38% more capacity than alkaline, and holds its voltage much better in cold weather. Worth the extra cost for long recordings, high sample rates, or cold-season deployments.
- NiMH rechargeable - also fine for standard deployments, and cheaper over many redeployments. Turn on "Use NiMH/LiPo voltage range for battery level indication" in the Configuration App first - NiMH has a different discharge curve, and the default Alkaline scale will misread it.
Buying tip: use three batteries of the same brand, chemistry, and age together. Mixing them in one holder is a common cause of premature low-battery shutdowns.
GroupGets doesn't currently stock AA batteries - any reputable brand in the chemistry that fits your deployment will do.
MicroMoth & AudioMoth Dev Li-ion / LiPo
Both use a 2-pin JST-PH connector supporting 3.7-6 V instead of AA cells. Open Acoustic Devices and GroupGets list MicroMoth as compatible with 400 mAh or 850 mAh Li-ion cells - a reasonable capacity range for either device.
Before connecting any third-party battery: JST-PH describes a connector shape, not a wiring standard, and polarity varies between manufacturers. Confirm the polarity matches before plugging one in - a reversed connection can damage the board. Prefer a protected cell (built-in over-discharge and short-circuit protection), since neither board adds its own battery management beyond what's documented.
GroupGets doesn't currently stock a matching battery - source one from a reputable RC or maker-electronics supplier.
AudioMoth USB Microphone USB powered
No battery needed. It runs on USB bus power from whatever computer or Raspberry Pi it's plugged into.
SD cards - what to buy
Open Acoustic Devices' own recommendation, based on their field testing, is a 32GB or 64GB SanDisk Extreme UHS Speed Class 3 (U3) microSDHC card. It works at every AudioMoth sample rate, draws comparatively little energy, and is well proven in the field.
Applies to AudioMoth, HydroMoth, MicroMoth, and AudioMoth Dev - all four take a microSD card. The USB Microphone has no SD slot; it streams live over USB instead.
Power draw by card
Card choice affects battery life more than the Open Acoustic Devices recommendation alone suggests: not every U3 card draws the same current, and it varies by capacity within the same product line, not just by brand. Approximate average current draw in milliamps (mA) at a few representative sample rates, from published testing:
| Card | 48 kHz (mA) | 192 kHz (mA) | 384 kHz (mA) |
|---|---|---|---|
| SanDisk Extreme 64GB | 14.0 | 32.8 | 41.6 |
| SanDisk Extreme 128GB | 31.7 | 67.1 | 70.7 |
| Kingston Canvas Select Plus 64GB Coming soon | 10.3 | 18.3 | 22.1 |
| Kingston Canvas Select Plus 128GB Coming soon | 10.2 | 17.8 | 21.3 |
| Samsung EVO Plus 64GB | 14.7 | 36.4 | 52.1 |
| AudioMoth Configuration App estimate | 10.5 | 20.0 | 24.0 |
The 64GB SanDisk Extreme that GroupGets stocks draws noticeably less than the 128GB, especially above 96 kHz. If a deployment needs the bigger card, budget for the higher draw when sizing batteries. Kingston Canvas Select Plus tested the most power-efficient across the board and stayed close to the figure the Configuration App itself assumes - GroupGets has these coming soon.
These numbers move. SD card manufacturers change the internal components of a given model without renaming it, so a card's actual draw can drift from published testing over time. Treat this table as directional, and retest a new batch of cards before a large or critical deployment.
Speed & capacity
U3 cards work at every sample rate up to 384 kHz. Below 48 kHz, slower Class 10 or U1 cards may work too, but Open Acoustic Devices recommends testing a card before relying on it for a real deployment, since performance varies by card and manufacturer.
For how much capacity a specific deployment actually needs, based on sample rate, duty cycle, and how long it'll be out, use the Battery & SD Card Calculator rather than guessing from the card's rated size.
Formatting & buying tips
AudioMoth reads both FAT32 (cards up to 32GB) and exFAT (cards over 32GB). Whatever allocation unit size your computer's formatting tool defaults to is fine - the library handles anything up to 32KB.
Buy from a retailer you trust. Mislabeled or counterfeit cards that report more capacity than they actually have are a real, well-documented problem in the memory card market, and a cheap high-capacity card from an unverified seller is one of the most common ways to end up with silently corrupted recordings in the field.
Test any new card with a short recording before relying on it for a real deployment.
Where this data came from
Sources
Battery chemistry and capacity figures come from Open Acoustic Devices' own battery guidance. The SD card recommendation comes from Open Acoustic Devices' SD card guide. The power-draw-by-card table is from published AudioMoth SD card power consumption testing across sample rates and card models. Product availability and pricing were pulled from the matching GroupGets listings at the time this guide was built, and can change - check the linked product page for the current price and stock.
A note on the JST-PH polarity warning
The caution about JST-PH connector polarity is general electronics knowledge, not something Open Acoustic Devices documents specifically for MicroMoth or AudioMoth Dev. It's included here because JST-PH pinout genuinely isn't standardized across manufacturers, and getting it wrong can damage a board - double-check before connecting any battery that didn't come from Open Acoustic Devices or GroupGets directly.
Not affiliated with Open Acoustic Devices
GroupGets sells the AudioMoth family but this guide isn't official Open Acoustic Devices documentation. For the authoritative specs, see Open Acoustic Devices' datasheets page.
© 2026 GroupGets LLC. All rights reserved. Not affiliated with Open Acoustic Devices.