__mod note:__title changed from '15% battery degradation after 42k miles' as it seems to be a misunderstand of how to calculate battery degradation

I have never given it much thought about my battery life. I figured that since I've only gone through 130, or so, cycles of my battery, I figured my degradation wouldn't really be noticeable. I have read articles on how little degradation there is on the model S, but I need to share my numbers because they are alarming. Below are the numbers I came up with on an excel spreadsheet of my kWh use today and my percentages. Below is taking into account the 5% buffer and is based on a 80 kWh battery.

Battery Capacity (kW/h) | 85 |

Battery Buffer (kW/h) | 5 |

kW/h for 100% charge | 80 |

Miles on my Tesla | 42,394 |

August 31st 2015 | |

Percentage at start | 91% |

Percentage after | 30% |

Percentage Used | 61% |

Total Energy Used kWh | 41.4 |

Miles Driven | 124.2 |

Average Energy (Wh/mi) | 334 |

61% of 85 kWh battery | 48.8 |

my 61% use kWh | 41.4 |

**67.9 kWh**

**That is 85% battery capacity**

To sum up, my % of decline is .357% per 1,000 miles. I know there is a curve but this is very alarming. When I purchased the car, I was not told that I could lose 36% the battery life at 100,000 miles. If anyone has other numbers to contradict or agree, please share. I will continue to track the numbers and update.

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