Qi Wireless Charger with empty battery /device turned off

[ncabane]

Hello everyone!
I have a Nexus 7 2013 with the micro USB port broken and with nearly no chance of getting the spare so i can replace it (i live in Argentina).
I was able to charge the tablet nonetheless, by putting some weight in the USB cable, but i can't now and the tablet's battery seems to be completely drained (when you press the power button it doesn't even show the battery icon on the screen)
Surfing along Mercadolibre (our Ebay) i came across a generic Qi Charger:




I tested it with a Nexus 4 and it seems to work properly. A blue light turns on when you place a compatible device on the surface.
So i placed the Nexus 7 tablet over it and the blue light appareared, i left it there for a few minutes, then hours, then a whole night and the tablet doesn't work, it doesn't turn on nor show any activity on the screen, having this:

Do you need the Android SO to be loaded in order to charge the device via QI charger?
Do Qi chargers work when you turn off your device or the battery is drained/too empty to start?

Please help!

 

[zedorda]

If it is totally discharged it could take weeks to get it started on the wireless charger. I had to leave my friends N7 plugged into a stock wired charger for 3 days before reviving his tablet.

 

[ncabane]

Then i have a little hope
I will leave it there the whole weekend and see what happens. If i remove the tablet from the charger for testing, it will loose all the charge?

 

[zedorda]

As long as the battery hasn't suffered too much damage from being discharged it should retain any charge it has accumulated.

 

[ncabane]

Thanks a lot! I will keep this updated if it revives or not

 

[ncabane]

It's charging since Friday. It didn't turn on so far