Powering my esp32 projects

[RSchlenker]

Hey Guys,
I am totally new to powering microcontrollers, that's why I am not sure about how to power my project correctly.
I wan to build a mobile setup using the esp32 WROOM-Breakout from board from sparkfun. Ideally, the power should last for a few days for my project. Basically, the projects consists of regularly accelerometer-data via bluetooth. In between the measurements the esp32 will stay in sleep mode to save power.
The size of the batteries is also critical, so I would prefer a smaller sized battery like a coin cell or a small LiPo-battery.
One possible power supply could be a LiPo battery 3.7V, 200mah. But during development, I am powering the project using the micro-usb port which provides 5V. So I am basically not sure if a 3.7V battery can afford the same power. As I know, the IO-pins are powered with 3.3V Does the breadboard down-regulate the 5V and will 3.7V be enough to power the esp32?
I have to apologize for such beginner-questions but I couldn't find a similar project reference to validate my assumptions.

Kind regards,
RSchlenker

[KanyeKanye]

5V power supply would damage esp.
Esp if you're not too frugal (wifi on, low value resistors for pullups) needs about 0.2A and your battery will die in 1 hour.

[peter_]

Hello,
it should be possible to power the ESP from a LIPO. They have often discharge rates of about 20 C/H (C = capacity in AH). But you need a voltage regulator with a very low drop.
I'm using the TPS73733. Maybe you can think about a switching regulator, but I don't know if this is the best choice for a Ultra Low Power application. The TPS73733 has a maximum Input of 5.5V so USB is no problem.

Kind regards
Peter

PS. (Just see that the TPS consums about 400µA so maybe you must look a little bit around for some regulator with a lower consumption.)

[Hans Dorn]

Maybe disable the TPS during sleep, and bypass it with a couple of Si diodes to drop the voltage into the safe range?


Cheers
Hans

[KanyeKanye]

Maybe a joule thief
You can use your 0.2Ah battery. Value 0.2A (and even more) I wrote before is true when everything is on. Just remember about it writing a code, switch into powersave mode as often as it is possible, use pullups 10k and do not use a wifi too often

[pjay00]

Hi RSchlenker,

Since you mention using a SparkFun board, as far as I know their only ESP32 product is the ESP32 Thing (https://www.sparkfun.com/products/13907). If you're using this board, it embeds everything you need for power management. Just connect a LiPo battery to the JST connector and the battery voltage will be correctly regulated for the ESP32. You can also plug a Micro USB cable to power the board and/or charge the battery, and again the 5V from USB will be regulated to 3.3V.

Cheers,

Philippe

[smartfarmer]

Hello,

Does anybody know what the maximum input voltage is an ESP32 board could handle?
I would like too built the board into a machine what has already a power supply of around 9 volts.
I am looking for an board which can coop with this voltage and has bluetooth.
adruino uno's are able up to 12 volt but do'nt have Bluetooth or WIFI built on.