Several finance/investment firms are indicating that Tesla MAY allow owners to temporarily buy extra battery range for purposes of long trips. See below. Why couldn't they do that now? Tesla will only manufacture two battery packs to create production efficiencies. The first will be installed on Model 60, 70 and 75 vehicles (with a total capacity of 75 kWh) with the other installed on Model 85, Model 90 and Model 100 (with a total capacity of 100kWh) vehicles. The vehicle's on-board software will control the available range of the battery and customers can pay for extended range and the software will unlock incremental battery power. The car's owner could pay for the extended range and power directly from the car itself. In addition, Tesla could also be set to offer an "on-demand" feature in which a customer can pay for additional capacity for a certain amount of time, such as during a long-weekend car trip.