I was just thinking if you are on your computer anyway would it just use some of the excess electricity that your computer would have wasted or would it be worse than charging your phone from a charger while using your laptop separately.
I was just thinking if you are on your computer anyway would it just use some of the excess electricity that your computer would have wasted or would it be worse than charging your phone from a charger while using your laptop separately.
Charging at higher voltage is more efficient (at least on electric vehicles) but also your phone is such a relatively small battery it barely matters. Avoid wireless charging as it is extremely inefficient.
USB PD (Power Delivery) actually does use a higher voltage for more wattage. Standard USB is limited to 5V at 0.5A and sometimes up to 5V @ 2A on quick chargers. But PD chargers can give 20V and 3A for 60w or even 5A (100w) with properly rated cables. There’s even a proposal for up to 48V at 5A to get 240w. This is all determined by a negotiation between the charger, the cable (which does have a small chip for this purpose), and the device, therefore PD chargers must support multiple voltages.