I haven't seen this anywhere else on these forums, so i figured i'd post this potentially useful info. Using the stock charger that comes with the inspire in conjunction with the Current Widget App, i have been recording the time it takes to charge the inspire over a variety of start conditions. I consider 100% full when current widget reports 0mA charging. I then took that data and plotted it with a corresponding trend line. There is of course a bit of variance due to any given percentage being associated with a range of current values, but the formula listed will give you a surprisingly precise ETA to charge your phone to full from any given start point. I hope this is somewhat useful.