Inverters are extremely useful to power devices that cannot be powered with 12v… however there is nothing more efficient than NOT converting 12v to 110v or 220v… then converting to 5v or whatever voltage your device requires. Sorry… that is a double negative. Let’s make it simple… we try to cut out the middleman if we can.
Charging laptops take enough energy… a unit like this works great and minimizes the power consumption. We try to find 12v power supplies for everything we can.
'Q' and Ehh! 