ESP8266 Community Forum

- Tue Apr 14, 2015 1:55 pm #14502 I am planning to do a test with a CR2032 coin cell. I did not realize those were actually 3.3v when new. I want to see how long I can get an esp to transmit data taking advantage of the sleep commands with the Arduino IDE:

wiki/doku.php?id=arduino-docs

What are other good light weight battery options? How tolerant is the esp with voltages below 3.3v? How tolerant can we expect it to be with voltages above 3.3? I found some good rechargeables on Amazon that are 3.7v.

What kind of batteries are you all having success with?

Thanks

- Tue Apr 14, 2015 4:05 pm #14513 I think you will find that the CR2032 coin cell will quickly 'give up the ghost'!

I am using BRC 18650 3.7v Li-ion batterys, they are available in various capacities. I am using 4000mAh, with a ESP-201. I have yet to test charge operational life.

- Tue Apr 14, 2015 5:08 pm #14523 absolute max voltage of the chip is 3.6V. I doubt that using 3.7V batteries, that when charged are around 4.2V is a good idea. For that very reason, i'm using 3.2V LiFePo4 battery. When charged at full capacity, they are arouund 3.5V and keep 3.2V for a very long time before droping lower. My esp usually work up to 2.6V. Which is good since LiFe battery can discharge up to 2V. I also think that cell coin will die fast.

- Tue Apr 14, 2015 6:12 pm #14529 Not that i'd recomend it, but i had an ESP-01 with a breadboard power supply accidentally set to 5v instead of 3.3v for a while and it still seems to work fine afterwards.