My iPhone 4 (going on 19 months of love) has recently started having a bit of an issue knowing the percentage of its battery it has remaining. I will be using it and it will jump from 31% to 19% and pop up that annoying "Low Battery" notification. A few moments after I dismiss it, the percentage jumps back up to 27%. This happens at least ten times, reliably, before it starts hitting 11% and then I know it was "real" and it needs charging soon. This feels like a NiCad issue… I know we've advanced past those days.
So my question is: how can I force a calibration of the percentage counter on iPhone 4? Alternatively, and I don't know that I would like this even if it is possible (I doubt it is), can I disable the "Low Battery" notification? It is excessively annoying when it pops up ten times over the course of thirty minutes.