×

Welcome to the Slashdot Beta site -- learn more here. Use the link in the footer or click here to return to the Classic version of Slashdot.

Thank you!

Before you choose to head back to the Classic look of the site, we'd appreciate it if you share your thoughts on the Beta; your feedback is what drives our ongoing development.

Beta is different and we value you taking the time to try it out. Please take a look at the changes we've made in Beta and  learn more about it. Thanks for reading, and for making the site better!

Comments

top

Nanodot-Based Smartphone Battery Recharges In 30 Seconds

robot256 Re:Extraordinary claims... (227 comments)

Ah, I see: http://en.wikipedia.org/wiki/P... "A pseudocapacitor has a chemical reaction at the electrode...This faradaic energy storage with only fast redox reactions makes charging and discharging much faster than batteries."

So, they made a new kind of supercapacitor, maybe with lower self-discharge than previous ones? A supercapacitor is exactly what I would expect in this application. Calling it a battery seems unnecessary and misleading.

about two weeks ago
top

Tesla: A Carmaker Or Grid-Storage Company?

robot256 Re:Not Rightly. Just Mightly. (151 comments)

If you're saying that a start-up energy technology that was poo-pooed by analysts for years could actually succeed in upending dozens of entrenched industries, then batteries seem like a pretty good way to go. The oil industry doesn't have a monopoly on Machiavellian corporate tactics.

about two weeks ago
top

Tesla: A Carmaker Or Grid-Storage Company?

robot256 Re:Giga market play (151 comments)

Fact: The U.S. power grid has continually reduced its overall emissions for decades now.

Fact: Electric vehicles produce less overall emissions than a 35mpg car, even on the dirtiest grid in the U.S, and most EVs are operated on much cleaner grids.

Fact: Over 1/3 of EV drivers own enough solar generation to offset the power used in their cars, making them truly zero emissions.

Zero-emissions electric vehicles exist now, if you have the money or lifestyle to fit it. I too think it will be a great day when hydrogen cars actually compete with battery-electric vehicles. But the obstacles we have to solve before then are many:

1) invent a way to convert electricity into hydrogen that actually approaches the efficiency of batteries, if not equaling it, instead of making it out of methane like we do now or wasting half your power in electrolysis.

2) build hydrogen fueling stations everywhere before a solid base of users exists to pay for it.

3) convince the public that hydrogen cars won't explode like the Hindenburg (stupid but important).

4) make them cheaper than an equivalent battery-electric car, because by the time all that gets done BEVs will be so far ahead you will wonder why you bothered with hydrogen at all.

Once Tesla has created a super-cheap source of grid storage batteries, everyone with an electric car can get solar and go off the grid. Then the power plants and centralized distributors will be forced to shut down. Then local grids will spring back up so people can use communal backup generators on cloudy weeks, but we will never again need the complex monstrosity of our present power grid because all generation will be local. We already have new factories installing enough solar and wind to power themselves, so it's only a matter of time before the grid becomes redundant and uneconomical to maintain.

about two weeks ago
top

Tesla: A Carmaker Or Grid-Storage Company?

robot256 Re:Panasonic (151 comments)

Not to mention, batteries for cars are are optimized for weight, while batteries for grid power are optimized for everything but weight.

Batteries for cars are optimized for weight, size, power delivery, low maintenance and cost. Batteries for grid storage are optimized for power delivery, low maintenance and cost. Size and weight are bonuses that make them cheaper to deploy (less land/manpower). So they really aren't as different as you make out.

No utility in their right mind is going to deploy billions of lead-acid cells that will need constant watering and replacement in 5 years when they could buy EV batteries cheaply (due to combined scale of manufacturing and/or reuse) and leave them in place for 20 years.

about two weeks ago
top

Tesla: A Carmaker Or Grid-Storage Company?

robot256 Re:Panasonic (151 comments)

Well, to be fair, Panasonic would not even consider building the plant as described if Tesla weren't providing the primary demand projections. Latest reports were Panasonic was still a little hesitant to go in whole hog, which is why Tesla is making so much noise trying to win them over.

about two weeks ago
top

Nanodot-Based Smartphone Battery Recharges In 30 Seconds

robot256 Re:Extraordinary claims... (227 comments)

It's not clear to me how those two things could be put together in the way they describe and do what you describe. If what you say is the case, then the capacitor has the same capacity as the battery, and if they can do that without making the capacitor 10x bigger than the battery, then their breakthrough is actually "ultra-high-energy-density capacitors" and not "fast-charging phone batteries". In that case, there are way more lucrative markets for that than quick-charging phones, and their choice of demo makes me think they were going for a quick youtube sensation and not an actual tech advertisement.

about two weeks ago
top

Nanodot-Based Smartphone Battery Recharges In 30 Seconds

robot256 Re:Something fishy.. (227 comments)

Yes 2000mAh will charge in one hour at a rate of 2 amps, and charge in 30 seconds at 240 amps. But the cell phone battery is 3.6 volts and 3.6*240 is only 864 watts, much less than the 1800 watts delivered by an extension cord. Assuming they deliver that to a DC-DC converter in the battery at 48 volts on the banana plugs they only need 18 amps, but that is still a lot. I still think the whole thing is cold-fusion-style vaporware.

about two weeks ago
top

Nanodot-Based Smartphone Battery Recharges In 30 Seconds

robot256 Re:Phones yeah (227 comments)

It probably also demonstrates something about how energy profligate that personal motor transportation really is.

Yes it does, especially when you consider that electric vehicles are 80% efficient compared to 20%-efficient gas cars.

about two weeks ago
top

Nanodot-Based Smartphone Battery Recharges In 30 Seconds

robot256 Re:Phones yeah (227 comments)

Actually, drag is the most important issue on long trips. Mass is less of an issue in EVs because you can recapture 60% of your kinetic energy when you brake, and mostly a non-issue when driving at a constant speed on the highway. Adding lithium batteries to a car without increasing the drag profile invariably increases the range.

about two weeks ago
top

Nanodot-Based Smartphone Battery Recharges In 30 Seconds

robot256 Re:Phones yeah (227 comments)

Long charging times for electric vehicles stop any journey where the trip is greater than the battery range.

Yes they do, but we don't need this tech to fix it. Existing batteries can do it just fine, if we would only invest in enough high power charging points.

about two weeks ago
top

Nanodot-Based Smartphone Battery Recharges In 30 Seconds

robot256 Re:Phones yeah (227 comments)

Existing batteries can charge to 80% in half an hour. The only thing stopping us is the scarcity of high-power charging stations, and making batteries charge faster only makes those stations more expensive and less likely to be actually installed. That is why improving battery capacity and efficiency, not the charge rate, and rolling out more infrastructure using the existing standards are the most important things for EVs right now.

about two weeks ago
top

Nanodot-Based Smartphone Battery Recharges In 30 Seconds

robot256 Re:Phones yeah (227 comments)

There's a pretty big continuum between 2 minutes and overnight. Existing EV batteries can charge in half an hour at a suitable fast-charger station with a manageable cable assembly. Making them charge faster simply doesn't help because it (a) does not solve the problem of needing expensive high-power chargers everywhere, and (b) creates a new problem because you need ridiculously high voltage and/or current capacity in all the charging cables.

about two weeks ago
top

Nanodot-Based Smartphone Battery Recharges In 30 Seconds

robot256 Re:Phones yeah (227 comments)

They aren't looking at charge swaps because the infrastructure cost is enormous. Better Place tried it in Israel (much smaller country with more political incentive for EV use) and went bankrupt because people really didn't need swaps as much as they thought they would, and because they could only get one model of car to use the compatible battery.

It's hard enough getting people to roll out the standard charging stations we have now and keeping them all operational, can you imagine getting 100x that investment before anyone even buys the cars? Now think about covering a country as big as the US with gas-station-sized underground robotic battery swapping facilities and keeping them all stocked and operational.

And since you will only have as many customers as you have buyers of compatible cars, to make the network viable you need lots of models using the same battery. We only barely managed to standardize the stupid plug, can you seriously imagine them agreeing on a fundamental part of their cars' chassis?

Battery swapping is a logistical nightmare. Sure, we could do it, but we could also build a base on the moon and rid the world of famine if we really wanted to, but we won't. Fixed 200-mile batteries and 10- or 20-minute superchargers are the most realistic way to go. (Tesla's superchargers work just fine without 00 gauge cables.)

about two weeks ago
top

Nanodot-Based Smartphone Battery Recharges In 30 Seconds

robot256 Extraordinary claims... (227 comments)

Am I the only one skeptical of whether this is real or not? What they describe doesn't make a lot of sense to me:

On one side it acts like a supercapacitor (with very fast charging), and on the other is like a lithium electrode (with slow discharge). The electrolyte is modified with our nanodots in order to make the multifunction electrode more effective.

So is it a battery or a capacitor? Maybe I'm just woefully ignorant of how lithium batteries work, but I was under the impression that it was the surface area of the electrodes and the activity of the electrolyte that govern the internal resistance, and hence the charge rate. Capacitance has nothing to do with it, unless you are charging up a capacitive "buffer" that drains into the chemical battery more slowly afterward, but that seems kind of pointless.

Pulling out buzzwords like "environmentally friendly" materials and nanodot "self-assembly" doesn't really help your plausibility, either. Anybody can make a box with banana jacks and an app with a timer in it.

about two weeks ago
top

Judge (Tech) Advice By Results

robot256 This is how they develop CPR training (162 comments)

In recent years at least, this is precisely the method they have used to develop CPR training for the general public. Even if a more complicated routine would result in a better chance of survival in any given case, they have to make the rules simple enough that people can remember and apply them years later and under stress. This increases the statistical survival rate overall, which is exactly the point.

But agree with everyone else, you could have explained this to a mildly intelligent person in about 1/4 of the words.

about two weeks ago
top

How the Internet Is Taking Away America's Religion

robot256 Re:Knowledge (1037 comments)

Reducing the number of pirates reduces the amount of piracy, increasing the efficiency of trade and spurring economic growth, resulting in greater energy use and thus global warming! Q.E.D.

about two weeks ago
top

Mazda Says Its Upcoming Gas-Powered Cars Will Emit Less CO2 Than Electric Cars

robot256 Re:Do electric cars actually produce CO2? (330 comments)

And therein lies the utter whimsicality of the U.S. transportation system. Every day we get up and get into our metal cube and travel 1, 5, 20, even 50 miles to work. Then at the end of the day we get back in and reverse the trip. Wasting billions of man-hours of mental effort every year simply trying to keep our metal cube from hitting someone else's metal cube getting from point A to point B. Yet every attempt to build a transit system that would off-load this responsibility to trained professionals performing it for hundreds of people at once meets almost insurmountable criticism and only the barest of funding offers.

The fact that every one of these metal cubes is burning fossilized dinosaur plants and polluting the atmosphere is just icing on the cake. Electric cars are admittedly only a coping mechanism to deal with this dystopia in the least destructive manner. I'm sure there are many people who simply don't consider or know about their public transit options, and drive as a result. But until we get serious about transit investments, there isn't much choice for a lot of people.

about a month ago
top

Mazda Says Its Upcoming Gas-Powered Cars Will Emit Less CO2 Than Electric Cars

robot256 Re:Do electric cars actually produce CO2? (330 comments)

"Burning American coal" is probably the lamest reason to buy an electric car.

about a month ago
top

Mazda Says Its Upcoming Gas-Powered Cars Will Emit Less CO2 Than Electric Cars

robot256 Re:Do electric cars actually produce CO2? (330 comments)

Only if you live in West Virginia and you know they don't have solar panels on their house. But you can rub it in the face of any Prius driver you want. I don't understand how they can be so smug when all they're doing is using a *little less* gas by driving an underpowered, overcomplicated contraption--if they REALLY wanted to help the environment they would be driving electric. That's why I went straight to a Leaf--even better for the environment, AND I get plenty of torque and perfectly smooth acceleration.

about a month ago
top

Mazda Says Its Upcoming Gas-Powered Cars Will Emit Less CO2 Than Electric Cars

robot256 Re:Do electric cars actually produce CO2? (330 comments)

This has been studied extensively as well. While specific chemistries have their own pollution issues, most EV batteries are made in Japan, Korea and the U.S., with relatively strong pollution controls. There is general agreement that the manufacturing impact is relatively small compared to the operating costs of both electric and gasoline cars.

It's easy to be skeptical of electric vehicles until you realize just how bad even the best gasoline cars are. All those tailpipe emissions are making you and the people around you sick. All the money you spend on gas goes back to the oil companies, and you know how they treat the environment... Not mention all the motor oil, frequent maintenance and potential breakdowns, and subconscious stress induced by the constant engine noise in a gas car. Whereas EVs are perfectly silent, never smell like gas or exhaust, have no routine mechanical maintenance and far fewer parts to break. And powering it with grid electricity costs between 1/3 and 1/5 of what a 35mpg car costs in gas, coming from power plants which are under constant pressure to improve their emissions. Or just put solar panels on your house and be carbon neutral.

about a month ago

Submissions

top

Windows 7 Download Emails Land in Spam Folders

robot256 robot256 writes  |  more than 4 years ago

robot256 (1635039) writes "Like many users, I pre-ordered Windows 7 from the Microsoft Store months ago for $XX. I waited all day for the download instruction email, only to discover it in my Gmail SPAM folder. A warning to everyone waiting for their downloads: check your spam folder before cursing Microsoft. This is one M$ email you don't want to miss!"

Journals

robot256 has no journal entries.

Slashdot Account

Need an Account?

Forgot your password?

Don't worry, we never post anything without your permission.

Submission Text Formatting Tips

We support a small subset of HTML, namely these tags:

  • b
  • i
  • p
  • br
  • a
  • ol
  • ul
  • li
  • dl
  • dt
  • dd
  • em
  • strong
  • tt
  • blockquote
  • div
  • quote
  • ecode

"ecode" can be used for code snippets, for example:

<ecode>    while(1) { do_something(); } </ecode>
Sign up for Slashdot Newsletters
Create a Slashdot Account

Loading...