Originally Posted by mkguitar
suggest you use the DC to charge your phone
( otherwise you suffer the losses of DC to AC back to DC at each stage)
there are DC car chargers for many computers available as well
the fewer steps up or down or inversion from DC to AC the more efficient use of power
I think you will find that an efficient pure sine wave inverter using the factory charging 110v cord will probably do as well, or better, than the 12v adapters, especially if the native voltage of the device is other than 12vdc.
I have tested nearly all of the things we had 12v adapters for, laptop, phones, etc and none of the 12v adapters used less energy than the 12v going to a small Samlex 120 watt PSW inverter to run them through the factory AC cord. The Acer laptop whose native is 19vdc was substantially more efficient on the inverter than on the DC adapter. We are phasing out our DC cords as the stuff gets replaced over time so no more sorting through them all the time, just use OEM AC cords.
There is a thread on this that ran a while ago, if you are interested in it.