Did I say anywhere that converting DC to AC and back to DC won't lose energy?
You clearly didn't bother to read up on the Omnicharge but keep dissing it anyway.
If you would have read up on it you might have found that you can even set it from AC to DC on the output and that it has a lot of different DC based ways to charge the V or any other device.
All I am saying is stop giving 'advice' on things that you clearly don't understand or at least present it honestly and not in a way as if you are an expert in it.
Power delivery over USB; QC Quickcharge; DC or AC doesn't seem to be your expertise.
Yes 9V coming out of the V's power adapter is the same as 9V coming out of the Omnicharge or any other power supply!
To all others that are interested in the Onmicharge. You can do a whole lot worse buying other power banks since the Onmmicharge has really a lot of intelligence and safe guards build in which other cheaper power banks don't have.