ESP8266 Community Forum

I have NodeMcu esp8266 v 0.9 and there is wifi and mqtt with relay that is operated with mobile and works as a charm. I buy some 4 aaa battery box with microusb and i want to power nodemcu up with it because i testing it over usb on my computer. How to increase buttery long life to power nodemcu? is this nodemcu little power consumer or not? Can buttery power works for a couple of months? I read about sleep mode but how nodemcu wakes up when mqtt message is sent from smartphone? How this works in general? i can wait until battery falls in power but if someone has the solution for the problem i will be greatfull for advice.
Thanx,
Faramon

WiFi is not a low power device. If the radio needs to be on continuously the power consumption will be significant. It will drain the batteries quickly. If it is to power a relay then that also will add to the power drain. The radio alone would last for less than a day on AAA alkaline batteries based on an average current of 75mA and a battery capacity of 1200mAH.

Bluetooth LE might be a better choice as far as power consumption. It is much harder to work with.

ok, bluetooth is maybe beter choice. But how anybody else creates wifi dht mini box and connects with raspberry pi, maybe wemo d1 mini is les current consumer or betr choice?

This looks easy http://bleduino.cc/ but I don't know what it costs.

Then there is Adafruit https://www.adafruit.com/product/1697

I have a couple of Bluetooth LE modules but I have not had the time to work with any yet. If you need a relay in your application then you should also look at that as it could be a significant drain on the batteries. Use a Mosfet transistor as a switch if you can.