The only thing smart I want is a faucet that activates with button OR the knee / foot sensor, and gives water always with a precise programmed temperature and flow.
That and a temperature and timer controlled frying pan.
Well an incinerating toilet that just dries burns my shit using a 340W solar panel would be cool too.
Basically amps is capped at 5 ampere, so it's watts / 5. So for 20V you need 100 watt. USB Power Delivery specification revision 2.0 does up to 240W with 48V which is pretty awesome.
I'd love a 20V battery for power tools that just has a USB3 plug instead of special chargers.