ESP8266 Community Forum

- Wed Jan 20, 2016 8:49 am #39294 Thanks for this writeup, lethe. I was suspecting my multimeter to add resistance, but couldn't yet explain it

I might just upgrade to one of those micro-range meters in the future, for now I'll survive. BTW, tried kick-starting the board, but as soon as I break the meter out, the board basically stalls and can't make progress - the display still has the juice, but no updates posted. Just an observation, for history.

On the battery power aspect - I'm feeding into a Vin pin, and NodeMCU (well, at least my version from the DoIT folks) has a AS1117L-33 voltage regulator on it, which should make it better, no?

Anyway, I haven't yet a single issue with the LiPo power and this board, and they're so cheap, I might not even bother in the long run, but thanks for the warning.

- Wed Jan 20, 2016 4:00 pm #39316 Yes, if the board has on-board voltage regulation, it's ok to feed it more than 3.6V.
In your particular case however, the 1117 might be part of the problem: it's rated for a drop-out voltage of about 1.2V, the input should be higher than 4.5V for reliable operation. You should try to use an external regulator, with your multimeter in series, connected to the 3.3V pin of the nodemcu dev board. That might solve your issues.

For "production" use however, I would advise you not to use the nodemcu dev board. The 1117 series regulators are unsuitable for battery use due to their drop-out voltage and high quiescence current of about 10mA.
A better alternative would be to use a ESP-12 (preferrably the F variant) and one of those white adapter boards with a better regulator mounted on the back (a XC6203 in SOT-89 package will fit and has less than 10uA quiescence current).