Hacker News Reader

Be interested to know what range they anticipate from the 4.5 tons of batteries

~infty / until the mechanical brakes are worn down after the battery is fully charged from driving.

it seems to be a perpetual motion machine then? Just needs consumables such as brake pads repaired?

The old UK milk floats had a range of 60-80 miles http://www.milkfloats.org.uk/faq.html

No, perpetual motion means more energy from less. This moves mined rock downhill, so the work of moving it uphill was done by geological formation.