I am planning a mini Cooper conversion and I was hoping to get a 130 mile range on one charge. I was aiming for a 40kwh battery capacity but this would be very expensive using new lithium batteries. What would be the best way to get a battery pack of that capacity for as little money as possible. I was thinking maybe I could find salvage electric cars at my local junk yard? Used batteries online are still pretty expensive. Any way to Source cheaper lithium batteries?