I believe the peak consumption of the ESP8266 can hit 300-400mA when transmitting, so yea that will kill a small battery pretty quickly for a chatty app. OTOH,

I believe the peak consumption of the ESP8266 can hit 300-400mA when transmitting, so yea that will kill a small battery pretty quickly for a chatty app. OTOH, if you can keep the device powered down most of the time and just wake up to fetch/report data occasionally, you should be able to get several months of life on battery. [edit] Adafruit says theirs peaks at 250mA, but that's still in the same ballpark. http://www.adafruit.com/product/2471 http://www.adafruit.com/product/2471