iBasso D2+ power

[JPeck]

I've got my iBasso D2+ last week, and I'm very happy with the purchase.
 
Just one question to everyone who owns it:
Does it use USB port power when it's connected to a computer regardless of the charge switch position?
 
I never turned the charge switch to 'on' position, but it's going without charging for more than a week.
Does it use its battery only when it's being used as an amp?
 
I think my Fiio E7 drains battery even when it's connected to USB if I turn the charge option off.

 

[JPeck]

Does anyone have an idea?
What's your experience with other battery-powered DAC/amps from iBasso?
 
My D2+ is going without charging for 9 days now.  Never turned on the charge switch.  I definitely used it more than 40 hours as the DAC+amp, but maybe less than 30 hours as the amp.  At this point, I'm pretty sure that it doesn't drink battery when it's connected to the USB.  Is it right?

 

[JPeck]

Ok.  Since nobody seemed to care, I asked iBasso directly.  The answer is, yes, it only draws power from the battery when it's used as stand-alone amp.  When it's connected to a computer via USB, it relies on the USB power.
 
I think FiiO E7, that I have, consumes battery even when it's connected to a computer if the charging setting is 'off'.
 
I don't know if one way is better than the other.