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The new batteries can also be recharged hundreds of thousands of times say MIT researchers

You could be charging your long lasting batteries in a matter of seconds in the future if several researchers at MIT get their way. According to a report on ScienCentralNews, researchers at MIT have discovered a new way of making batteries that involves using millions of nanotubes. Leaping over traditional battery technologies, the new types of batteries are based on capacitors, which have been around even longer than the battery itself.

A capacitor maintains a charge by relying on two metallic electrodes. The actual storage capacity of a capacitor is directly proportional to the surface area of those electrodes, and unfortunately making a capacitor in traditional battery sizes means that the electrode surface area is simply too small. To overcome this, the researchers cover the electrodes with millions of nanotube filaments, effectively increasing the surface area.

According to research team leader Joel Schindall "[the nanotube battery] could be recharged many, many times perhaps hundreds of thousands of times, and ... it could be recharged very quickly, just in a matter of seconds rather than a matter of hours." With such promise, Schindall and his team believes that the new technology will revolutionize portable electronics as well as the automotive industry. "Larger devices such as automobiles where you could regeneratively re-use the energy of motion and therefore improve the energy efficiency and fuel economy."

The research team at MIT is hoping that this new promising technology will show up in the market in less than five years from now.


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Charging power requirements
By cmlburnett on 8/9/2006 11:04:30 AM , Rating: 5
What isn't mentioned is the power requirements to achieve "seconds" in recharge time.

Consider a 3.6 V 10 AHr battery. It would take 10 amps @ 1 hour or 1 amp @ 10 hours to charge it. So to get it done in 1 second it would require 36,000 amps. Or 10 seconds would be 3,600 amps. Assuming constant voltage during charge then you're talking 130 kW for 1 second or 13 kW for 10 seconds.

Anyone got a 130 kW electrical service at home?

Now if you're talking a hearing aide battery then you're obviously not talking 10 AHr batteries. If you're talking hybrid cars then you are also definitely not talking about 10 AHr battery packs.

A 100 mAHr 3.6V battery would require 139 W for a 10 second charge. That's quite reasonable.

A 100 AHr battery pack would require 1.3 kW for 17 minutes to charge. That's also quite reasonable, but not "seconds".

Mind you that this has absolutely nothing to do with the battery technology and assumes 100% charging efficiency!




RE: Charging power requirements
By rrsurfer1 on 8/9/2006 11:26:15 AM , Rating: 2
Obviously charging cars would be limited to either low-rate trickle type charging, or using a commercial charging station that could supply the current.


RE: Charging power requirements
By ianwhthse on 8/9/2006 11:35:04 AM , Rating: 2
Or other technologies such as regenerative braking.


RE: Charging power requirements
By rrsurfer1 on 8/9/2006 11:40:56 AM , Rating: 2
Bingo. The key is it 'allows' high current recharging, which can be useful in many situations. You can always charge slower if needed.


RE: Charging power requirements
By TheDoc9 on 8/9/2006 11:51:11 AM , Rating: 2
that is bad, but you could also use the same argument with the gas tank of a standard car.


RE: Charging power requirements
By glenzilly on 8/9/2006 12:07:33 PM , Rating: 2
"A 100 AHr battery pack would require 1.3 kW for 17 minutes to charge. That's also quite reasonable, but not "seconds"."

The typical average home has a 200 amp, 240 volt service for a total of 48,000 watts. This is then divided up between circuits ranging from 15 amps to 50 amps. Assuming a 30 amp, 240 volt circuit (a typical circuit for a dryer) you would have a total capacity of 7.2 kW. This would cut the 17 minute time down to three minutes or so. The battery charger could also be a unit that stores electrical power between charges and could reduce these times as much as is technically feasible and cost effective.


RE: Charging power requirements
By lucyfek on 8/9/2006 12:35:04 PM , Rating: 2
europe's got the advantage here - 220v in outlets makes current requirements 2x lower so it's easier to do this over existing grid. other solution (better in my opinion) is to have a "power tank" at home, trickle charge it over long time and - when needed - charge the car battery in seconds by connecting two capacitors together. in similar way commercial "charging" stations can be built (only the statons' capacitors had to be huge, but it'll be easier to hook the business up to high voltage lines). there could be problems with safety - a small capacitor can shock pretty well, now imagine what a big one can do. and the "slave" cables had to be made ofsuperconductor (at true room temparature, not available yet) or some heavy and super-thick copper. one more problem is that - according to some research that i'd read on the internet - no country has enough electricity (and grid able to handle the load) to switch to entirely electric vehicles. sad but true, but the only solution to gas prices is (and be for some time to come) to drive less.


RE: Charging power requirements
By johnsonx on 8/9/2006 4:24:52 PM , Rating: 2
The power grid in the US is 220-240 volts also. Only half is usually fed to each 'regular' outlet, but the full voltage is available in the main electrical box (and often times 1 or more 240v outlets in the garage or laundry area).


RE: Charging power requirements
By lucyfek on 8/9/2006 9:06:48 PM , Rating: 2
120/240v - i have to check on this one (and true, i know that there is big outlet for oven, dryer...but i'd thought these were 3 phaze current outlets). i don't understand why someone set stanadard voltage to 110 (it kills just like 220, but requires more expensive wiring) and transformer station with two separate volatages and power lines seem complicated (time to read somehing on this). in europe you get 220 but with some tricks you get 360V (3 phase current - maybe not in regular apartments, but at single homes, farms etc no problem) (or whatever is it).


RE: Charging power requirements
By MontagGG on 8/10/2006 7:55:31 AM , Rating: 2
Sorry to rain on you parade, but 3 phase power in US is either 230 or 460 V. Also, you guys have 50 hz power cycle, while the US has 60 hz. Higher frequency for the win!


RE: Charging power requirements
By lucyfek on 8/10/2006 10:47:37 AM , Rating: 2
well, it happens so that i've moved to States so we get wet together. i was just trying to say that 110 seems wastefull (transmission loss, more expensive wires), but i,m in no way an expert on 3p current (and the effective voltages on both sides of the pond). as the simlest example of waste - try to use a vacum cleaner (~1k) and check the power cable - hot - i've never noticed the same thing back in 220 land (unless the power cord was the sh... possible). 60 Hz - good for old tv (less flicker but lower resolution over the same band). different standards - bad for all of us (unless all the stuff you use works over any voltage/frequency)


RE: Charging power requirements
By johnsonx on 8/10/2006 1:58:15 PM , Rating: 2
no, they don't supply two different voltages. A 230v AC circuit consists of two wires, each with a 230v peak-to-valley 60hz waveform. The two waveforms are 180 degrees out of phase, so if both wires are attached to one device, it gets 230v AC. To supply power to the regular 115V outlets in a home, only 1 of the main supply wires is connected to a given circuit; the other wires in the circuit are are grounded (yes, the 'neutral' pin and the 'ground' pin in a 3-prong house plug are both grounded; there's no real difference between the two). So relative to ground, a device gets 115v AC.

(or 240/120v, or 220/110v... voltage levels vary a bit; I think the official US standard is 230/115, but I've measured anywhere from just under 110 to just over 120... seems 117 or so is what I see most often).

Secondly, transmission loss isn't an issue related to the final supply voltage. The ONLY time voltage on the wires gets as low as 240v is on the final run from the pole to the house; I don't know the exact voltages, but the voltage on the local (neighborhood) grid wires is somewhere in the 1000 volt range. The bigger lines that carry power from the substations to the local neighboorhood grids are higher again, and so on till you get to the 100,000 volt (and higher probably!) distribution lines.


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