Builders are trying to go to capacitors and wheel motors. No wear out of batteries and waste to deal with. Don't know the run time. Volvo and Jeep both are looking at it I think. Imagine a capacitor that could "fuel" a car for 400 miles. That capacitor would carry enough electricity to power a thunder storm. Not really that scary, a car battery or even big flashlight batteries can kill a person if handled wrong. ear