Letting you use the extra batteries will create more warranty issues later which are not subsidized at the price you pay for the car. Imagine cars came with go

Letting you use the extra batteries will create more warranty issues later which are not subsidized at the price you pay for the car. Imagine cars came with governors for instance that could restrict speeds and acceleration to limit wear and tear on a vehicle and provide the consumer with a lower cost upfront thanks to less warranty work needed. Similar concept.