delivered to the battery in 1/12 hour, at a rate of (75)(12) = 900 kW, which
will vaporize the battery.
Obviously if these batteries can charge 10 times faster than normal batteries, as advertised, they must be remarkably efficient so they do not produce much waste heat. Most of the 900 kW would convert directly into electric potential, and only about 90 kW converting to heat. That's pretty hot, but with a good radiator and exhaust fan it would not vaporize the battery or cause a fire. With a lead-acid battery, which is 70% efficient, it would produce 200 or 300 kW, which *would* cause a fire.
Think about this carefully, and multiply by 10
cars at a time. Ot think about it in a remote rural station on the road from
nowhere to nowhere else.
Ah, but imagine the rural station equipped with buffer battery of batteries (BBB). Let's say enough to charge 5 cars. This would smooth out the flow and allow a reasonably small main electric feed. A huge charging station on a major highway with 20 charge bay slots might require a BBB large enough to hold a charge for ~100 cars, and an electric power main large enough to recharge the BBB in 2 or 3 hours. It would not need power mains capable of charging all 20 slots simultaneously.
If the 20-slot BBB recharges in 2 hours it would demand only 1/4th the power of a direct system with no buffer. In other words, the station manager would assume that over his busiest 2-hour rush hour period only 5 of the charge bays slots are filled on average. All 20 might fill up briefly, but on average only 5 are filled. If more customers show up they have to wait for a while while the BBB refills. If that happens often, the charge station manager has to purchase a larger BBB and possibly another main power line.
Direct charge for the 20-slot charge station would call for 18 MW power mains; a 2-hour BBB would call for 4.5 MW; a 3-hour BBB would need 3 MW, which is reasonable.
Remember, you would only need charging stations on busy highways. A back road charging station might be part of a general store, and it would only need a BBB capable of servicing one or two cars, with a 4 hour recharge time (450 kW main).
In a busy city where there are no charging stations, from time to time a driver might leave home without realizing the car is about to run out of power and cannot make it to the office. He would be out of luck. He would have to pull into a Dunkin' Donuts store and use their friendly customer "emergency charge slot" which would take 15 or 20 minutes for a partial recharge (say, 20 kW), and cost him $5. He would eat a doughnut while he waited, and he be late to work. This would not be a big deal because it would not happen often. These cars will be a lot smarter than today's cars. Their computers will learn the drivers habits, the way TiVo gadgets do, and computer will warn the driver in most cases, with a verbal message: "If you are about to leave on your daily commute you will probably run out of power."
When a driver arrives late to work and covered with doughnut crumbs, he will plug in the car at one of the charge slots in the parking lot, and leave it to charge up all day. Office building parking lots might have five or 10 charge slots, or about as many as they have handicapped parking slots now. They would only be needed for people who forgot to charge up or people who commute a very long distance. These slots would require only modest power mains, because they would recharge as slowly as the overnight main at home.
The current litium ion technology is expensive. Lead acid batteries are good
for delivering huge current surges necessary for starters and highway
passing. I assume lithium ion batteries can be designed for automotive
service.
The Toshiba site describes hybrid engine applications:
"The new battery can quickly store energy produced by locomotives and automobiles. This speedy and highly effective recharge characteristic of the battery will support CO2 reduction, as the battery can save and re-use energy that was simply wasted before."
- Jed
