[jagger27]

The point is to remove the laptop power brick. Let's say the laptop charger is 90% efficient, which is fairly typical. The post claims their 12VDC to 240VAC inverter is 92% efficient. A 12VDC to 20VDC voltage booster would only have to be >83% efficient to beat that setup.

[colejohnson66]

Which isn’t that hard for a switch mode converter. Those are usually 85% or more IIRC.