Media-Tech MT3145 - replacement of the battery with a permanent power supply

Hello,
Anyone know what are the permissible supply voltages of the system implemented in this portable speaker?
Currently, a Li-Ion 18650 3.7V battery is installed
Since the laminate is damaged due to the detached MicroUSB input, I would like to make an external power supply for it and I wonder if ordinary USB is not enough, but I have concerns if the 5V voltage will not be too high and no resistor is required, etc.

Laminate marking: DXP-A10-2.2.PCB.

Standard USB to 5V.

Freddy wrote:

The USB standard is 5V.

foxxer672 wrote:

but I have concerns if the 5V voltage will not be too high and no resistor is required

The power supply has to be made 3.7V and the battery removed

18650 cells most often have a voltage range of 3.7-4.2V.

Any stabilized power supply that gives voltage in this range will do.
Get the LM317 (set to 4V) or the rare 7804 (I saw such a miracle in my brother's stereo).
Linear stabilizers require about 2V more at the input. For 4V you will need around 6V at the input.


Alternatively, just find the + 5V, GND (ground) lines and reconnect the cables to them.
It would be more elegant because there will still be a battery.

Thanks for your help, I'll use the LM317