u/Careless_Power7809

I need a power bank that has enough capacity to fully charge a laptop and can charge itself reasonably fast. My laptop can charge itself fully from 0 in about 90 minutes; why do power banks charge themselves so slow? Currently I have a 20000 mah power bank which only gives my laptop about 1/2 charge and takes FOUR hours to charge itself. It’s been really hard to find something that meets what I’m looking for. Is there anything out there that can fully charge a laptop and will charge itself in 2 hours or less?