The 1A figure might be more of a precaution - can't find anything "official" from Espressif (ESP8266 manufacturer), although most people on forums seem to agree

The 1A figure might be more of a precaution - can't find anything "official" from Espressif (ESP8266 manufacturer), although most people on forums seem to agree 500mA is as low as you want to go. Seems you can expect ~250-300mA to be normal when using wifi. Anecdotally, I've experienced reliability issues when running off 500mA, but that could just be my setup + accessories. It's funny how it works - last time I went down the rabbit hole on the tail end of a late night session, everything pointed at 1A being considered "safe", and anything lower was "iffy". If you put the chip into any of the Deep Sleep modes, power consumption goes way down to just a few mA's, making battery operation much easier. http://www.esp8266.com/viewtopic.php?p=57788#p57788 http://www.esp8266.com/viewtopic.php?p=57788#p57788