For this article I decided to use my Bogart Engineering Pentametric Analyzer to track the ampere hours and watt hours of energy consumption. Throughout the entire test the battery bank voltage remained at 13.3 - 13.4V.


The iPad was charged via a 400W Cobra inverter to mimic the way I see most of my customers charging iPads, via an inverter.


In order to get to 76% SOC the iPad and inverter inefficiencies consumed -3.91 Ah's or -51 watt hours from the battery bank.