So basically I haven't used my iPad in about 2 years or so. I recently found it in my drawer. I tried charging it and sometimes it gets to the low battery and black background screen. I left it for about 2 hours or so, and it didn't work, so I tried another charger, and it still didn't work.
TL;DR: Found my old iPad, put it in charge and it didn't work, even with a different charger (waited for around 2 hours).