I'd like to deploy my project so I'm looking for a way to power the nodemcu. I'd like to know if there's a way to power it with a 9V battery without any other external circuit.

Until now I've found information for the nodemcu 1.0 and it supports up to 20V on the VIN port. Here's the article I read: http://henrysbench.capnfatz.com/henrys-bench/arduino-projects-tips-and-more/powering-the-esp-12e-nodemcu-development-board/

I'd like to use the two port: 5V and GND but I'm not sure, here there is no VIN port and I'd prefer to not burn my board. Are there any better way to power my project?

  • you can feed more than 5v in, especially for short periods of time.
    – dandavis
    Apr 17, 2018 at 5:47

1 Answer 1


It looks like the 0.9 uses the SPX3819 regulator. That can run with up to 16V on the input, so 9V on the 5V pin (as long as USB never gets connected) should work fine.

Except: 9V PP3 batteries are useless. If it can even provide enough power to run the board (which is doubtful) it won't last more than a few hours. You would have to ensure that you use very very deep sleep mode to get any semblence of longevity out of it.

The 3.3V regulator will be throwing away half to two-thirds of the power as heat. So wasteful. You would be better off investing in a 3.3V switch-mode ("buck") regulator circuit (cheap on eBay) to directly power the 3.3V pin of the board instead of 9V into the on-board regulator.

  • Thank you, I'm actually using DeepSleep in fact the board should sleep more or less for 6 hours, wake for few seconds (1 min max) and the go to deep sleep again. I cannot use a power bank because when the board is in deep sleep because it stop to provide power
    – Timmy
    Apr 16, 2018 at 16:11
  • About the 3.3V regulator, does the AMS1117-3.3 is ok? From here I read that the Vin-Vout should be between 1.5V and 12V, is it correct? advanced-monolithic.com/pdf/ds1117.pdf
    – Timmy
    Apr 16, 2018 at 16:21
  • That is just as inefficient. But it can handle more current before it melts.
    – Majenko
    Apr 16, 2018 at 16:22
  • You want to look for a "UBEC" (that's the magic word). Something like this.
    – Majenko
    Apr 16, 2018 at 16:24

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