Can't edit nor delete. Please ignore this thread and reply to my other 
one.

IN+ is for the + pole of the battery
GND is or the - pole of the battery

VO+ is the positive output of the module

I did not found a description for the EN pin. So I would to connect it 
with GND or IN+. On the back side you need to close one of the solder 
bridges to select the output voltage.

It would be better to get the documentation first before buying things.

On the microhpone amplifier, the connector are well labelled. VCC ist 
for the power supply. IN is the input and out is the output. For all 
three pairs, "-" is the same as GND.

Hi, I am not sure, but at first sight this module resembles HW-613 to 
me.
You would have to check yourself, whether this is actually your module
Here are some details for module HW-613:

https://micro-pi.ru/hw-613-mp2315-%D1%81%D0%B8%D0%BD%D1%85%D1%80%D0%BE%D0%BD%D0%BD%D1%8B%D0%B9-step-down-dc-dc/

or translated with google, but images not loadable:

https://translate.google.com/translate?hl=en&sl=ru&u=https://micro-pi.ru/hw-613-mp2315-%25D1%2581%25D0%25B8%25D0%25BD%25D1%2585%25D1%2580%25D0%25BE%25D0%25BD%25D0%25BD%25D1%258B%25D0%25B9-step-down-dc-dc/&prev=search&pto=aue

peasant wrote:
> Hi, I am not sure, but at first sight this module resembles HW-613 to
> me.
> You would have to check yourself, whether this is actually your module
> Here are some details for module HW-613:
https://protosupplies.com/product/mp2315-mini-adjustable-dc-dc-step-down-module/

Careful with EN connection voltage, in case the smps controller is 
MP2315 and the EN connects directly to MP2315, as stated in my links

MP2315 pins:
AAM
IN
SW
GND
FB
VCC
EN/SYNC
BST

"ABSOLUTE MAXIMUM RATINGS
(1)
VIN ................................................–0.3V to +28V
VSW........ –0.3V (-5V<10ns) to +28V (30V<10ns)
VBST........................................................ VSW+6V
All Other Pins ..................................-0.3V to +6V "

peasant wrote:
> Careful with EN connection voltage, in case the smps controller is
> MP2315 and the EN connects directly to MP2315, as stated in my links
>
> MP2315 pins:
> AAM
> IN
> SW
> GND
> FB
> VCC
> EN/SYNC
> BST
>
> "ABSOLUTE MAXIMUM RATINGS
> (1)
> VIN ................................................–0.3V to +28V
> VSW........ –0.3V (-5V<10ns) to +28V (30V<10ns)
> VBST........................................................ VSW+6V
> All Other Pins ..................................-0.3V to +6V "

Had forgotten to write this, from my Protosupplies link, which may 
apply:

"Output Enable

The module has an EN (Enable) pin which is active HIGH.

"The module has this pin pulled high by default, so the module will 
always be enabled and the EN pin can be left unconnected if the module 
will always be enabled."

A. D. wrote:
> So V0+ is actually an OUTPUT connector?

Yes, but it is an O (like Output) not 0.

A. D. wrote:
> If I need a 5 V and a 9 V output (for two different devices) would I
> need to connect them using 2 of these step down power supply modules?

Yes, one module has only one output.

A. D. wrote:
> So, you would suggest to connect battery and consumer to the step down
> power supply module the way I sketched in the above image?

In case this is directed to me: tbh, I have never bought a buck or boost 
module, I've built very simple ones though. So I don't really have any 
experience with connecting readymade ones. And i don't want to take 
reponsibility, so therefore I just provide more links, in which people 
connect modules, which look like yours. And actually I guess I would 
connect the module as you have
https://www.youtube.com/watch?v=-JmNfzPLv5o
https://www.youtube.com/watch?v=BC46PkzsCe8