power use on a MHL-HDMI adaptor?

[funkylogik]

ok i have one of the ones with a micro usb wire leading to a lil box with HDMI out and micro usb in for charging.
id assumed it was just so that you could charge while usin HDMI but my battery SLOWLY drops.
is there a good tech reason why the adaptor requires power supply?
do phone USB not have a power output?
ta

global s3, UK. Ask me anything and ill reply even if its just an intelligent (or stupid) guess

 

[funkylogik]

sly bump

global s3, UK. Ask me anything and ill reply even if its just an intelligent (or stupid) guess

 

[GSDer]

My, my - Mr. Funky is quite the impatient one
Heh heh, actually, I never saw your first post...
I don't think that the adapter itself requires power, but just the fact that you're using the adapter implies that your phone is going to be under a heavy load (watching movies; playing games; etc) so that it's going to be taking a hit on battery life. Keeping the charger plugged in helps to ensure that your porn (uh, I mean, History Channel series about the rise of Scotland) doesn't end abruptly or that the phone isn't dead when you unplug the adapter.

Sent from my rooted, debloated, deodexed Sinclair ZX-80 running CM -0.001 using Tapatalk 2

 

[funkylogik]

lmao right just wish it broke even instead of dropping 1% every 10mins for my "extended documentaries lol.
strange thing is, the unit doesnt work without charger even when phones tanked up
pity i cant turn screen off... i set it at min brightness n it doesnt affect output

global s3, UK. Ask me anything and ill reply even if its just an intelligent (or stupid) guess