I'm considering the Fusion Hybrid as my next car. I live in the San Francisco Bay Area and one destination is Lake Tahoe via I-80 or Hwy 50, both of which have long stretches of up-the-mountain driving at higher altitudes (up to 7,000+ feet). I'm wondering if the battery runs out of power on those stretches, leaving you with the low-power gasoline engine only and resulting in very poor performance on those high-altitude uphill runs.