hi guys, i am experimenting with nodemcu-wroom-esp32 dev kits.
it looks to me when i wanna operate it from Vin it is a bit over-power-hungry.
previously i used 4xAA size eneloop pack (nominal 4x1.2V 1900mAh) with esp8266 nodemcu kit to my good satisfaction, as the eneloop chemistry provided well even for WiFi peaks.
but not with esp32.
i ended up with a stabilized 2Amper table supply, step along 3v-4.5v-6v-7.5v settings and the 7.5V was able to run my rule set till the end (esp-easy-mega firmware).
then i refined and added to the eneloop pack another AA (alkaline) (i am ultimately a bad guy)so it made 6.5v and that was the barest minimum voltage to make a full run despite the power LED was shaking a bit on TX peaks.
next step (and so my setup will be) i tried 2x 18650 Li-ion. It looks to feed that board enough through the onboard ams1117 LDO.
stranger thing when i use usb cable from power bank it runs stable from its 5V 1A socket. (ok it has higher 7500mAh rating and some other with 16000 and 20000mAh).
somebody from netherland scoped out esp boards and he found during WiFi TX peaks the board eats above 400mA.
so that 150mA-200mA just the average.
my device is sitting unpowered and weekly 1-2 times operated. for this i'm using a push button and a 3V solenoid self latching relay. i push the button to start up the rélay to give power to esp32, then gpio from the program i shut down the relay.
as the relay coil 45 ohm it takes 50 to 100mA to trigger it (but typical time 2ms to finish flip), but for me is less headache than struggling with deepsleep modes and wake up methods.