Can I charge a 19V laptop from multiple USB ports?
My laptop’s charger is rated at 19V 2.1A. I was wondering if it would be possible to build an adapter which would allow me to charge it from a power bank, even if just slowly or via multiple USB ports.
I know you can buy adapters which utilise USB power delivery, but most outlets and powerbanks don’t have PD yet.
Your laptop’s charger is rated for about 40 watts. There are USB power delivery chargers that can deliver more than 40 watts. So yes you can build it.
There are USB to barrel adapters out there, you could use one of those, but if you want to design the circuit yourself that would be a fun project. You would need something that could negotiate USB power delivery