For anyone wanting to complete the extension Tim mentioned in this guide and add the built-in rechargeable battery and battery management module, rather than the easier route of using a USB battery bank I’ve got some tips below.
I’ve tested a battery management module (DFR1026) from stock and the default behaviour is that the unit doesn’t supply power to the output unless there is a short-press on the built-in switch to turn power on. A long-press of 10 seconds disables power to the output.
This means the simplest project build can just use the built-in switch on the power management module and no external switch is required.
If you wanted a button that you can use to turn the device on or off from outside the case you could use a button riser to extend that button to outside the case (This is how buttons work a lot of consumer devices ).
Another option would be to connect a power switch between the battery management module and the Bluetooth receiver, this will allow you to power the device with a simple switch you add yourself but this does mean the battery management module is always operating, so your battery life will drain a lot quicker than using the button on the module to disable power output.
Below is a quick sketch outlining the simplest way to wire the speaker project and add the rechargeable battery.
