Tony, from what I've read on the myEV by myCarma site, the app will also report battery degradation. This is one of the main features of the app. In fact, the people behind the app are tauting to their Indiegogo contributors the app's ability to do this fairly accurately. They claim they have an EV battery "expert" on staff who developed a special algorithim for this purpose. So, if they really have something good, it may be that the logged values reported for beginning and ending SoC are already adjusted for battery degradation. In which case, the maximum value for SoC at 100% usable charge would be 41.8kWh, but that value slowly declines over time. Of course, most of us getting the app (promised in October) have RAV4 EVs (and/or other EVs) that already have thousands of miles on their batteries, so how does this algorithim factor in any pre-existing "aging" of a battery? Also, is there stored data in the car that the logger can read via OBD-II port that tells the app how many hours and charging cycles have already occurred on a battery? I presume the OAT and/or battery temperature can be pulled by the app as well.