To reduce power consumption, I wanted to check if the mini speaker I bought would run without a battery. This way I can leave the speaker in the on position, and power it via its usb socket. Only when the system turns on will the speaker turn on. And it won't waste energy by charging an additional battery we don't need.

Opening the speaker was easy, and it has a tiny Li-Ion or Li-Poly battery. It measured 3.7V, and the open circuit charging voltage was 4.7. Cutting the black battery wire I checked it would run powered at 5V - which works. This draws about 100mA during loud moments.