For this second part of the charging observations I chose to use a USB 12V adapter as opposed to an inverter.
This particular 12V USB adapter is has an output rating of 5V and 2.0A which is 0.4A less than the output of the Apple 120V adapter. All this means is that it will take a bit longer to charge.
This one is branded Rayovac and I grabbed it at Wal*Mart.. The standard Apple USB to lightning cable was used.