Toshiba has come up with a lithium battery that can get to a 90% charge in five minutes. This is huge for electric cars, if it pans out. Anyone want to work out how much power/voltage/current that would be for the equivalent of a tank of gas?

Um, such batteries have existed for quite some time. American A123 is selling in powertools and RC models. RC modellist crowd routinely recharges those packs in 10-15 minutes, depending on how fat cables they have.

Most Lithium Phosphates with low internal resistance can be charged that quick, lithium titanates as well. Charging a huge pack is limited only by how fat power cables you have, or if you have spare "buffer pack" of similar batteries around.

Thats not news now, for a few years already.

as for charging an electric car, Tesla ( teslamotors.com ) roadster has roughly ~50kwh battery pack, for over 200-mile range.
At 110volts, getting 50kwh into batteries in an hour mean pulling 500amps, in 10 minutes would be 3000 amps.
A "tad too much" for household breakers. So either specialized charging stations, or buffered storage in form of flywheels or buffer batteries, neither of them cheap or easily available option.

There's a big difference between fifteen minutes and five minutes when you're recharging your car on a road trip. The latter is much closer to the delay required to pump gas in the tank. So I'd see a high-current charge at commercial stations, and a low one overnight at home.

Well, like i pointed out, the recharge rates arent really limited by batteries any more, but the available amps from the charger. A123Systems batteries, PHET ones, Valence or a bunch of other brands could be easily charged in 5 minutes right now as well. Toshiba is just jumping on the bandwagon.
The variable that limits the recharge rate in batteries is basically internal resistance, and they have gotten it silly low with lithium phosphates, especially with nanotech-improved cathode materials. The things are shipping in commercial quantities, i am not talking laboratory tech.
By the way, TEPCO with Mitsubishi and Subaru ( MiEV and R1E preproduction models ) are fleet-testing such fast charge stations already, with smaller battery packs, like 15-20KWh or so.

Phoenix Motorcars in US reportedly developed and is testing some already as well, i dont recall off the top of the head where. They are using Altair Nano lithium titanates in their car.

Kert - I'm very suprised to hear this claim - I thought the big problem for RC hobbyists was that lithium batteries must be charged slowly (at 1C) to be safe. Emphasize: TO BE SAFE! Is that wrong? Do you have any references for RC hobbyists? In general, I thought the big rap on lithium batteries, so far, was safety.

Abominable: You are talking the old lithium cobalt oxide and polymers. These things tend to burn or explode when overcharged, yes we all know that.

Lithium phosphate ( and manganese ) is an entirely different beast basically with no fire hazards. They are a bit lower sepecific energy though, but way higher specific power. 10C safe discharge rates.

I am not making this up, google on "a123, RC" or something.

if you are interested in RC stuff, theres lots of forums and A123 is selling for RC hobbyists through
A123Racing.com

But to really see what these batteries are made of .. look up KillaCycle ( killacycle.com ) . They have A123 battery pack in the thing. Hows 7.824 quarter mile sound to you ? ;)

Kert, It is great to learn something new! Very impressive! Now the price has to come down!

re: price. the chinese are working on that furiously.
A123 sells for like $1000/kWh, there are reports that Chinese Thundersky ( also LiFEPo4 ) can be had for $200/kWh. For a usable EV pack of few tens of kilowatts you are looking at few thousand bucks.

There are other Lifepo4 battery brands springing up like mushrooms in china, and they are quickly ramping up capacity. The patents be damned, as usual.

Heres an article that talks about A123 cells used in RC helis, also saying that they DO charging in five minutes:
http://www.evworld.com/article.cfm?storyid=1174

But i must say, if you havent heard about LiFEPos, and are interested in RC, you must have been living under the rock for a past few years :)

>you must have been living under the rock for a past >few years

Or something. It is interesting that traditional sources like Tower or even slightly more hip sources like bphobbies dot com aren't selling these yet. (Right?) Any idea why? I don't want to get involved and then have it literally blow up in my (or a kid's) face.

Lots of RC stores ARE selling them, also lots of equipment like chargers have been accomodated ( these cells have slightly different charging algorithms, different pack voltages ) and are selling stuff like voltage level converters etc.
Simple google turned up this:
http://www.brchobbies.co.uk/?page=shop&category=7

There are also specialized new chargers on the market specially built for recharging these cells, as normally the power levels werent just needed, nobody had cells that would be able to take that power. Google on it a bit, and read the rcuniverse or rcgroups forums.

There have been a few independent folks performing all sorts of safety and durability tests on these things, i havent heard a bad word anywhere yet.

And don't forget the problems with just the connection; a cable capable of handling 3000 Amps will be extremely heavy and inflexible if I'm not much mistaken (not to mention as big around as your head...)

Mitsubishi thought they found the way around the cable connection problem: inductive and microwave chargers. They demoed the conept in the new I Miev Sport they just showed at Tokyo and other motor shows.
Inductive has been tried before with RAV4 EVs and it works pretty good.

How dangerous is an inductive charging station at those power levels?

Also, the catch is still the kwh/lb and kwh/$ (counting full life-cycle costs). Fix those, and either revamp most gas stations with chargers or add an engine and generator for long hauls, and you're set.

Warning: Napoleon numbers ("Horseback approximations") follow.

Gasoline is about 130 MJ/US gallon. Taking into account the efficiency of a typical IC engine, that's roughly 10 MJ/gal available to spin the wheels.

If the tank is 20 gallons, 2x10^8 joules available.

5 minutes is 3x10^2 seconds. If we assume it's done at 13200 V (typical neighborhood distribution voltage, before the transformer) 2*10^8/(3x10^2 * 1.32x10^3) = 2x10^3/3.96 =~500A. Decrease for longer times, increase for smaller charging voltages. At 200V, 2*10^4/6, 1666 amperes.

My ampacity tables don't go that high.

Regards,
Ric

"How dangerous is an inductive charging station at those power levels?"

About as dangerous as letting untrained masses handle highly flammable liquids in high volumes and lug it around in their cars ..
Look, there are engineering solutions for sane safety levels. The "paddle" inductive chargers used with RAV4EVs constituted of a paddle that goes into a slot in the car, effectively making a transformer.
You are connecting a magnetic flow, not the electric. I dont see any significant danger in such construction. Yes the cable needs to be fat, but gas hoses are quite fat too.
Also, if you have specialized stations, you can use ( sanely ) high voltages like 600V or so, commonly found in industrial buildings, which will bring your amps down to sane levels again.

And yes, the catch is ALWAYS the costs. kwh/lb is sufficient to build cars with 200+ mile range, as apparent from cars like Tesla and others.
Wrt to full life cycle costs, most LiFEPos have cycle lives above few thousand cycles, where their capcaity drops to like 80% level. Even with a full charge cycle every day ( highly unlikely, nobody drives 200 miles average in a day ) you are talking about nearly ten years of life. Thats a lifetime of a car.

The devil, as usual, is in the details of course, but viable electric cars have been possible for quite some time now. Auto industry is slow to respond, but even the giants are slowly waking up, with GM Volt, Saab/Volvo plugins, Ford plugin SUVs and Toyota planning a plug-in Prius. Mitsubishi, Subaru, Nissan and Renault have full electrics in a pipeline, Mitsu even has a production date set to 2009.

As a woman on the waiting list for a Tesla of my own, this is a subject I've been brushing up on lately. Ric, your numbers are off. If the current is coming at 13200V, then a 50 Amp line would be fine -- six gauge wire, say. I think you lost an order of magnitude someplace. For the 200A case, I get 3333 Amps, and that's just too thick a cable for a girl to lift.

Insulation and such are clearly going to be at issue with the voltage that high - but the car already has a pretty great inverter in it so I don't see a reason it can't charge off of high voltage DC just as well. I mean, flat out the car draws maybe 200 kW if I remember my materials correctly. A five minute charge is a bit over three times that much - if the batteries can take it, great.

I have speculated that if someone really wanted to make it easy to use, that the car's inverter (needed to convert AC from the motor to DC to charge the batteries during regen braking) would be able to take AC out of the wall instead and just do "Faux-regen" from the wall socket. It'd all depend on how the inverter is designed, and this is a subject about which I know nothing at all (magic box full of chips or elves, beats me), but it would be elegant.. especially if you used your 240V dryer connection to do it in your garage. A five hour charge-up would only need 50 amps or so at that voltage.

Now, if Tesla could just figure out how to make that 2 speed transmission to work probably first.....

"I have speculated that if someone really wanted to make it easy to use, that the car's inverter .. would be able to take AC out of the wall instead"

This is actually often being done with AC electric vehicles. Curtis controllers have it wired up that way, IIRC, and Siemens Simovert line had this too.
It takes only a slight modification to the seven-pack IGBT block in the inverter. It saves BOM costs for the inverter and charger put together, the IGBTs at these power ranges dont really come cheap.

Regarding the snark above about the transmission, you do know that its a electronically driven clutchless system that does not throttle down during shifting, right ?
Its not like many have attempted that before.

"to work probably first.....
Posted by Josh Reiter at December 15, 2007 06:36 PM

doh!...work properly first.

Not to mention that Honda are apparently moving to capacitors for their next generation of hybrids and, if rumours are true, we might see capacitors able to power vehicles in the next 12 months.

Induction stations shouldn't really be any more risky than playing with petrol, not to mention you can still trickle charge them over night at home.

Then all we need is an agresive program of Nuclear power station development so we can save oil for important things like aircraft and plastics.

Just looked a little closer at the a123 system. Says the batteries work up to 120F. Uhh, that not good enough.