ESP8266 Community Forum

- Tue Feb 03, 2015 1:24 pm #8873 While I am aware this isn't an ideal solution, I am going to use an ams1117 and take the onboard output of the 5v usb connector and step it down to 3.3v. I know there will be a lot of efficiency losses from stepping up the voltage just to step it back down, but it's a simple way to get it done. I have it completed now, I will let you know what kind of battery life I get.

Edit: It lasted 12 hours with 2 Ultrafire 2000 mAh 18650 batteries. I was polling a DB18S20 once a minute and uploading to thingspeak, no sleep mode. While I expected somewhere between 20-30 hours, I haven't capacity tested the batteries, I'll try to get to that. Also going to try sleep mode, even though there seems to be issues with that.

- Thu Apr 23, 2015 8:43 am #15374 Hi Aonko,
I had one of those $10 battery pack for cellphone and I power an esp12 module which get the temperature from and DHT22 module and send to thingspeak every minute then going to deep sleep.
It runs since 27h and the battery is still over 4v, should last quite long time.
The battery should have around 1900mAh.

I reckon we should remove the step up and we should get 5/15% of battery life due to the efficiency of the step up converter.

Cheers,
Plucker