Short Battery Life

I am using a ---

Arduino Pro Mini 328 - 3.3V/8MHz

With a ---

SparkFun RFM69 Breakout (915MHz)

I am powering it with 4 AA batteries connected to the RAW input.

Under normal operation it should only transmit or receive about six times a day.
My batteries seem to have gone dead in two weeks or less.

I had the system in an outdoor electrical box which got quite wet inside
and blew one of my Arduino minis which I replaced.
Might this be the cause?

What should I expect for battery life?

Is there a better way?

jack0987:
I am using a ---

Arduino Pro Mini 328 - 3.3V/8MHz
https://www.sparkfun.com/products/11114

With a ---

SparkFun RFM69 Breakout (915MHz)
SparkFun RFM69 Breakout (915MHz) - WRL-12775 - SparkFun Electronics

I am powering it with 4 AA batteries connected to the RAW input.

Under normal operation it should only transmit or receive about six times a day.
My batteries seem to have gone dead in two weeks or less.

I had the system in an outdoor electrical box which got quite wet inside
and blew one of my Arduino minis which I replaced.
Might this be the cause?

What should I expect for battery life?

Is there a better way?

Your battery life all depends on how much current your project uses and for how long.

Paul

Alkaline AA batteries have about 2500 milliampere hours (mAh) battery capacity.

Two weeks is 336 hours, so that says your average battery drain is about 7 mA. Sounds about right for the Pro Mini.

See this excellent tutorial to learn how you can extend AA battery life to a couple of years, or this one to learn how to run your project on solar power.

You should be able to run the same project for the same amount of time on 2xAA batteries as well. Connect it to the 3.3V pin, instead of the Vin pin. Haven't tried it with the RFM69 but the RFM95 (LoRa) modules do great on 2xAA.