Quote:
Originally Posted by heero_yuy
I think people are putting too much faith in battery technology improving.
There is however some simple physics that shows why this is not really viable: Say you had a 100 KWhr battery, this is enough to give a decent range, to charge it in 1 hour requires 230v at 440 Amps excluding inefficiencies. Just think of the cable thickness and "plug".
Now you want a fast rechage at a garage say, 6 minutes? that's 4,400 Amps!!! A cable to carry that would be so heavy you'd need a crane. The magnetic field generated by such a current is likely to erase things in the vicinity.
Quick refilling and long range can only be got from a fuel cell / hydride tank using Hydrogen. A simple swappable tank cartridge could have you filled up in under a minute and the tanks are recharged with Hydrogen at the garage, generated using surplus electricity, where you stopped. The fuel cell can also be run "backwards" for a slow recharge of the tank at your home.
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Hydrogen has to be manufactured on earth, and the process is expensive and energy intensive. It must also be shipped around in heavy pressure vessels. It is more efficient to use gerenated electricity to directly charge a consumer's battery than it is to use electricity to gerenate hydrogen and then distribute it to filling stations (using lorries which presumably are also consuming hydrogen as they go).
Much has been said about the limits of lithium battery technology, both in terms of its theoretical maximum capacity and in terms of the world supply of the metal. However, researchers are now moving towards previously unknown chemistries that can potentially double the capacity of a lithium battery (or half the amount of lithium in it, for the same capacity). There is also some very promising research into calcium ion battery tech, as described here:
http://newenergyandfuel.com/http:/ne...ion-batteries/
They key to electric cars is range, not charging speed. If you have a car that can go as far as you can reasonably drive in a day, it doesn't matter if it takes a few hours to recover that range overnight. I have no doubt we will achieve that long before 2040.