Velleman PCMP15 Manuel page 4

Connect the other end of the USB cord into the power supply.
This can be a computer or 230VAC-5VDC power adaptor (not incl., ref
PSSMV14)
The red LED will light. When fully charged, the LED will turn green.
Charging times range from 1 to 2 hours.
4. Powering Your Device
Once charged, the unit can power a wide range of devices. Press the
power button. The green LED will light. Connect the USB connection to
the PCMP15 and the other plug to the device.
You can now use your device or let it recharge. For the best results, we
recommend recharging your device, disconnect it and use as normal.