Powering project from 3.7 lipo should I go up or down

Other Hardware General Electronics
1

Having a project with an esp32 and 3 devices ( Df player, servo controller and voice recognition module). All can work at 3.3 or 5V. If i use a 3.7 Lipo battery, is it better to use a buck converter to go down to 3.3 or a boost converter to go up to 5V ?

2

I use these with LiPo batteries for ESP32 projects, and have never had a problem.

It is also vastly more energy efficient that boosting, then regulating back down.

If you are using an audio output device with speakers and or servos, then a different power plan for the high current draw is required. Servos must be separately powered.

3

Personally, I use a SEPIC (Single-Ended Primary-Inductor Converter) and don’t worry about it. It automatically switches between buck and boost modes to maintain your set output voltage. While it's not quite as efficient as a dedicated buck or boost converter, it’s a very convenient solution.

5

Thank so iff all the boards can take 3.3 or 5V, which way would you go with the SEPIC ? up to 5V or down to 3.3. That's what I'm trying to decide.

6

So you think going down to 3.3 is better than going up to 5 V in you case ?

7

The ESP32 boards that take 5V have a step down regulator that converts the 5V back to the 3.3V required by the ESP32.

That step down regulator is usually a linear regulator, which gives off heat to make up the difference between 5V and 3.3V, thus wasting battery life.

Stepping down from 3.7V to 3.3V wastes much less energy and makes much more sense.

8

When you use those buck converters, with the 3.7V batteries? what do you use to charge the Lipo batteries ?

9

I use a LiPo battery charger.

10

Hmmm...
There are many Esp32 dev boards that have battery management on-board. You can connect lipo directly and recharge through USB port.

11

I looked at the link you sent. Those are rated for 500mA.
I have the Df robot voice recognition bord that says maximum operating current <370mA, the df mp3 player mini says up to 200mA, and I’m not sure how much the esp32 boars and the PCA9685 servo board uses.
Do you think I will still be ok with the 500mA ?
Otherwise I saw Adafruit has one that has a 1.2 A output.