Maybe it is rated for a total of 15 Amps @ 5vdc total across all ports (which would be a really nice hub!). IF it shows the total power being consumed in real-time, that would be an awesome feature for some people.
The USB-A port is rated for 5vdc maximum and all USB-A devices are 5 volts. SO having a 15V hub would not make any sense.
Power is measured in amps or watts.
Maybe it is rated for a total of 15 Amps @ 5vdc total across all ports (which would be a really nice hub!). IF it shows the total power being consumed in real-time, that would be an awesome feature for some people.
The USB-A port is rated for 5vdc maximum and all USB-A devices are 5 volts. SO having a 15V hub would not make any sense.
USB-C can do higher.