Batteries always seemed fun to me - trust me, making circuits so they don’t blow up, really isn’t. Nimit recommended me to use a DW01A chip with my TP4056 chip for my battery management system. After quite a bit of research, I did not find a pre-soldered module I can use - so I built it myself! What helped me is this schematic I found on the internet:
[Source]

After downloading some footprints from LCSC, I used them to make a similar circuit myself!
You can ignore the buttons on the right, they are for the menu controls. The circuit charges the battery if it receives power from Pico VBUS (which is the Picos 5V output), and uses the batteries energy to power the circuit, if the switch POWER_SW is turned on. The voltage then goes through a voltage booster to ensure, that the 3.7 Volts, which the battery supplies, is being boosted to 5 Volts - which is good to power the Pico!

The new components are hidden under the screen in the state of final assembly. Below is a picture which shows their position!

Another minor change: the board now uses the same mounting holes everywhere. I have adapted to the screens mounting holes - why use two different sizes, if one works as well? I hope that makes my life easier later. This means I only have to get one sort of screws and the designing of the case should be a little easier. I have also attached a picture below:

Today I did not work too much on the project, so these are all the changes from today!