So to summarize, the best option is to have one of those boards from my first post, a 5V booster plugged to the output of that board to power up the nano (or use a micro without booster), and either have a usb port for charging a another for data, or a usb hub. How does the latter look like? Amazon link or similar?
Aslo note that you should not use the ‘battery output’ to power the Nano when there is no battery present.
I’m sorry, I’m not sure I understood you.
My plan is to solder a 1S lipo battery, not using a 18650, for example. But even if I did, the battery output when there is no battery is 0, isn’t it? Or you mean to power the nano with the port located in the charging board? Because that makes no sense. In any case I would power it with the cable wired directly in the nano port,and only because I would be loading some sketch.