While reading up on the various full electric and hybrid car models now available, and despite the much-vaunted new battery technology, it struck me how little real
progress is being made for a practical, long life, high energy vehicle battery. Crunching numbers, it seems that new models have very modest actual specific energy
, at the road, of less than 100Wh/kg. Gasoline has 10,000Wh/kg to put that in perspective, so even at 25% efficiency it seems far superior, [and take away the Gummint subsidies and sales would probably plummet]. Toyota use NiMH in the non-plug in Prius, [Prii?], restricted to about 35-75% of full-cell capacity for life-extension - and which will give no better SE in practice than Edison’s 1906 alkalines, albeit at higher discharge amps - and no gassing – but Edison’s cells will literally run for 100 years! Li-ons are similarly restricted. Go lower than 20% of full charge and the cells are ruined, and they deteriorate fast, no matter how they are treated. The new Tesla Sedan has a claimed 200 mile range - but the battery is a mighty slab that occupies the entire floor pan, 8” thick or more. Here, like Brunel’s first transatlantic steamers, range has been won by building a really big, big ship, reducing drag to 0.24 and filling it with coal to the gunnals!