Comment by Michiel

Here are the stats from my MacBook Pro (also mid 2009, 13-inch, original battery):

  Temperature = 2990
  CycleCount = 488
  DesignCycleCount9C = 1000
  DesignCapacity = 5450
  MaxCapacity = 4804
  WearRatio = 88%
  CurrentCapacity = 4804
  ChargeRatio = 100%
  Voltage = 12568
  Amperage = 253
  InstantAmperage = 88
  TimeRemaining = 0:8
  AvgTimeToFull = 0:8

I seem to be missing the InstantTimeToEmpty and FullToEmptyTime data. Reading your script, that tells me the values are "None" but not why that is. I'm also apparently 8 minutes from an empty battery, even though it's fully charged. Do you know why this is?