One or two years ago, I thought to extrapolate the usage time of the battery based on Anton's battery applet, before I wrote the code I did one simple test, and the result shows that the battery measurement is imprecise, so the time seems to be useless. My original algorithm works depends on the time difference and battery difference,
Use Time= Left_Batter/(delta_battery/delta_time), but some running results showed the delta_battery will increase in most of time.