Setting up a rechargeable battery for a NodeMCU 12-E board

I'm trying to figure out how to create a rechargeable battery power supply for a NodeMCU 12-E board. I've done some research and am still a little confused on how to approach this project. I've never done anything like this before and am having trouble understanding how this would be even possible.

Basically, I want to place this board in a case that has an ON / OFF switch. When it turns on its going to perform a task and when it turns OFF I want to put it into deep sleep until it turns on again. I also want to have the option for this to be rechargeable because I will be carrying it around in my pocket.

I've done some research and found some sources. It seems like a good approach would be to use a Pololu 3.3V, 500mA Step-Down Voltage Regulator D24V5F3 connected to a battery? and then have that deliver power via the 3v3 pin to my board.

Has anyone does this before and can offer me a simple set-up / general advice on this.

Please let me know if this is unclear as I am not sure what I even need for this.

Thanks all

Roughly you will need all of these components:

  • A rechargeable battery (18650 lithim batteries) or you can even choose small LiPo batteries (for example, the one used in drones)
  • A good discharging mechanism to ensure stable 3.3V to your NodeMCU/ESP12
  • A USB port + a charging board with chip like TP4056 or TP4056X to charge your battery

I had a similar requirement and all of these components separately would be kinda difficult to handle so I just bought a board which had all of these built in from here:

It has a small OLED screen with buttons to navigate the screen, I found it quite useful for my application. Cherry on Top. I just flashed the Lua firmware and made the application using that. But if you don't require that then just don't use it to save power.

It has 3 options to choose from:

  • Monster V4 board which has two 18650 Lithium batteries + TP4056 charging circuit + charging port
  • Normal V5 board which has one 18650 Lithium battery + TP4056 charging circuit + charging port
  • Mini V2 which has no battery holder like above but has a LiPo battery connector (the one used in small drones)

Personally I went for the monster board which has two 18650 batteries because that is most compact and has biggest battery capacity.