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Why Batteries Haven't Kept Up
TimWeigel writes "Ever wonder why we can cram ever more computer power into smaller and smaller devices, but we're still (mostly) slaves to the almighty AA? This article on CNN touches on this very important facet of our lives - why the power sources for our Palm Pilots and Gameboys haven't matched the advances in computing power. In a word: physics." I had an interesting conversation with a person who's been doing a lot of research into batteries. Batteries have grown at standard normal industrial rates - which are much slower then Moore's Law, and hence, the source of our problem.
Smoke detectors aren't powered by nuclear decay. The americium is only a source of ionizing radiation, knocking electrons off of oxygen and nitrogen. When smoke enters the chamber of the detector, the drop in current between the upper and lower plates (supplied by a battery or house current) triggers the alarm.
No. Americium decay doesn't power the smoke detector, it's part of the detection circuitry. It provides neutrons that are used in a sort of single purpose mass spectrometer. The power is provided by batteries or the mains.
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I have a Canon Powershot G1 digital camera. It uses a proprietary lithium-ion battery, about the size of a C or D battery, but more square in shape. This battery is fantastic. The camera can run for hundreds of photos, you can leave the viewscreen on, and use the flash a lot before you have to recharge. Through many charges it seems to have no degradations in performance.
On the other hand, I have a Dell Inspiron 4000 laptop which has a lame battery. It is also lithium-ion. When I first got my laptop the battery would last about 3 hours before having to recharge. About a year later, it would last barely 1 hour. Dell knows their batteries don't last very long and only warrant them one year (despite the 3 years I have on the rest of the machine!). I found this out when I contacted them 1 year + 1 week after I bought the laptop. I ended up writing a small windows app called BatteryLog to help track your battery performance. You may want to give it a try on your laptop before your year-warranty runs out.
So basically, it's more than just the technology of the battery, it's also the design and manufacturer. There are some good ones out there!
Even the highest energy density capacitors are easily out stripped by the lowest energy density batteries. Granted thay have made huge strides in the past years with the Ultra capacitors and at some point break even with batteries. You can now get multiple Farad capacitors but that is still peanuts in comparison to an AA battery. On the other hand research may at some point allow them to catch up or surpass batteries.
Dump those $15 battery chargers, get a good one, and you'll only need one Set of batteries for every appliance for the rest of your life.
my other sig is a 500 page novel
Consider the "need to know" shortcuts in this article. For example "1859, when the first lead acid battery was made in France". This was the first cell using Planté type plates which are still in use today, but the history of lead acid and other cells goes back a bit further than that. It's a reasonable shortcut, but it does illustrate that this kind of article only skims the very surface. If you want insights, you have to go and do your own research.
On the other hand, they do make an important point: "Of the billions [of cells and batteries] sold each year, most wind up in landfills and incinerators". Well, that's pretty much true of AA type alkalines and carbon-zincs, but actually clunky old automotive lead acids are now recycled 95% of the time. NiCad's though are death in a tube: nobody wants to touch the bloody things. NiMh's and Lithium Ions are a little nicer, if you can find a local recycler who will handle them. Power Express used to accept small amounts of NiMh's and LiIons by mail, but they've changed their site and I can't find any mention of it now, which perhaps indicates the volatility (ha ha) of the recycling market. If you want some sleepless nights, have a look here for a decent overview of what you can and should be recycling.
Oops, but then we slip into the land of delusions again: "Batteries, which have long been derided for polluting the environment, will soon do their part to clean it up, MIT's Sadoway said. The same research that is shrinking cell phones has a higher purpose: an exhaust-free electric car."
Uh huh. Like the T Zero? Again, the site has changed, and I now can't find mention of the technologies, but from memory, it's either 300kg of lead acids (shorter range or quicker death from deep discharges) or nickel metal hydrides (landfill ahoy) with quoted replacement costs and times of $3000 and 3 years for the lead-acids. Yes, that's 100kg of lead, acid and plastic to be recycled every year for every vehicle, or about half a pound (and $2.75) a day. OK, it can be recycled, and the problem is concentrated rather than distributed. But it's a lot of nastiness to deal with, and remember that rules only apply to nice middle income people. Scurrilous low income types are just going to abandon their twenty year old wrecks (complete with 200kg of lead) in the nearest ditch, street corner, or even front yard. We'd better be prepared to treat these things as environmental time bombs and have policies in place to collect and recycle them, with or without the owner's consent. Designing in a large recycling burden just makes less sense than investing in a clean and long lived internal power source.
I think that the intro sums it up: the problem is chemistry. There's only so much energy you can store in a sealed unit. If we want significant energy density from a renewable source and no ongoing recycling nightmare, then we have to go to hydrogen cells or even good old fashioned alcohol burners. Sealed cell technology is not the long term answer to our energy needs, and we can't just blame the manufacturers for that, seeing as how it's us that keeps buying their products by the billion then (mostly) throwing them in the trash.
If you were blocking sigs, you wouldn't have to read this.
Several studies were done by various organizations in the late 80s and early 90s (and its your job to look them up for specific examples) to determine if electric cars were really "green" if you took the emissions from the production of electricy to recharge them in to account.
The results...even when energy production for recharging is taken in to account, electric cars were found to be MASSIVELY less of an impact on the environment than their internal combustion brothers.
I want a new quote. One that won't spill. One that don't cost too much. Or come in a pill.
I think you sum it up nicely. It's the revenue from spares and replacements. I bought a used laptop with a dead NiMh from eBay for about $270. The battery manufacturer (Solomon) isn't even selling these batteries any more, but there's a generic Duracell equivelant, ranging from $105 for the dumb battery to $150 for the smart version.
Consider that this pack is pretty much equivelant to 10 x 1.5 (actually 1.2)V MiMh AA's, costing $50 or less for ten good cells. The dumb pack is charging a 100% markup for the form factor and contacts, and (no doubt) a very cheap recharger. The NiMh in my other laptop gets very hot while charging, which is about the last thing you want to happen.
An interesting how-to on making up an external power pack for a digital camera using 5 x 7Ah F cell NiCd's (totalling about ten times a typical laptop battery's capacity) can be found here.
To power a 12V laptop, you need 10 x 1.5v cells (which actually deliver about 1.2V each). Using various types of (e.g.) Sanyo NiCd's (although I'd prefer NiMh's, as cadmium is nasty-nasty), you could use:
Compare and contrast with my 3.5Ah pack at about 250g. Even with stock AA's, I'd get over three times the capacity and life. If I wanted to lug a lump of battery around, I could run the thing for days off of battery power. Actually, my laptop expects 19v DC in through the power jack (to recharge the 12v internal battery), so you could multiply all these figures by up to 1.5, if you felt like (realistically) powering a laptop for a working week off of a 7 lbs F cell pack.
If you were blocking sigs, you wouldn't have to read this.
the maha mh-c204f. you can read about it at thomas distributing.
i have this charger, and use it with ni-cds and ni-mhs, and it works great. really saves money. i use nimhs in my discman and my palm, and soon in my minidisc player. i highly recommend both the charger and thomas dist.
complex
unlike the ingenious Gameboy Advance low poer color screen which requires sunlight but last a long time on its batteries.
You were doing pretty good until you called the GBA screen "ingenious". Even in bright light, that thing is horrible. Literally, no hyperbole, that screen is the worst screen ever created. Bar none.
Having your batteries last a long time doesn't do you any good if your EYES wear out after five minutes.
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They're two different tools, used for different tasks and designed differently as a result. It's like you're trying to compare how many miles per gallon you get in a motorcycle vs. a chainsaw. One of those measurements won't make much sense.
Your G1 draws far less current at a far lower rate than your laptop. Your laptop has a hard drive that's probably constantly spinning while you're using it, while your camera's only motor is in the zoom lens. (OK, you might have a microdrive, but that doesn't stay spinning nearly as long as the drive in your PC.) Your camera's backlit screen has about 5 in^2 of illuminated area, but your laptop's screen is closer to 180 in^2, a 36 times larger screen that draws close to 36 times as much power. Flashes are also not a constant power draw. Finally, its off to your CPU to check current draw. Camera CPUs are more closely related to dedicated microcontrollers than they are to the general purpose CPUs found in your laptop. Microcontrollers are designed for minimal current draw, they power themselves down nicely (and frequently. While your Pentium was designed with low power laptops in mind, it still draws a frightfully large amount of current in comparison to the little processor inside your camera.
If you were able to wire up your camera's battery to power your laptop, you'd find you'd get maybe ten minutes of battery life. There's not magic inside that battery, and that's basically the point of the whole article.
John
John
Lithium-Polymer technology exists and is widely used in devices like Sony's MiniDisc portables and (better) laptop computers, such as Apple's Titanium PowerBook G4 which gets a staggering 8-hour battery life. The economics of the commodity market of the Wintel universe do not allow for this level of engineering and premium battery technology, so people settle for higher power consumption and lesser batteries that run for about 3 hours.
If I recall correctly, batteries are basically chemical capacitors. (Two surfaces of different electric potential separated by a resistor)
Batteries and capacitors are quite different. Batteries use electrochemical reactions that produce a near-constant potential (voltage) across the terminals, until the reactants are used up.
Capacitors work by polarizing a dielectric material [a physical change, not a chemical one] between two closely-spaced plates. The terminal voltage is proportional to the amount of charge (time integral of current) the capacitor is holding.
Modern capacitors are approaching the energy capacity of batteries. A 50F 2.3V capacitor holds 132 J of energy, which is equivalent to 120 Amp-seconds (or 33 mA-hours) at 1.1 Volts. This capacitor costs CDN$17.88, compared to $2.17 for a 250 mAh AAA NiCd cell. (prices are from Digikey in quantities of 1000)
So the capacitor's about 8x the cost for 1/8 the capacity of the NiCd.
We make memory chips using microscopic capacitors. What limitations keep us from packing a bunch of those together to make a more powerful battery?
One big limitation is that we only make our memory chips one layer thick (vs. multi-layer capacitors), and that these capacitors are optimized for storing information, not energy. The more energy stored per cell, the more heat is wasted every time that cell switches state.
I've found that there are moderators out there who, if they disagree with you politically, are jealous of the display of intellect you show on a particular post, or just plain don't like you, the following happens:
They click on your user info page, and mark down all your last few comments when they have moderator points, thus wrecking your karma, and destroying the visibility of your posts.
There was someone who did that to me, because he didn't like my perfectly valid (if opinionated) post.
Thus, abuse of the moderation system.
Of course, this post will be marked offtopic, even though deep-nested comments should NEVER be marked offtopic due to the fact that normal discussion almost always goes off in other directions than the topic, but, I digress...
I would have marked you back up had I not already spent my moderator points.
"Alcohol, Tobacco, Firearms, and Explosives" should be a convenience store, not a government agency.
Sigh. One more time, for everyone who missed it. NiCad cells have a FUNDAMENTAL problem. They grow whiskers of Cadmium internally when recharged by simple reverse-DC , which causes internal short circuits. This is why they lose capacity. This is why a large capacitor discharge can sometimes recover them. This is why they suck. If someone makes a good charger (i.e. one that reverses the charging current periodically like the rest of the electro-plating industry has done since the year dot) then NiCads are fine. They are just VERY VERY picky about how they are recharged. What you are seeing is a stream of new chargers on the market (e.g. the one I bought from RadioShack in New Orleans last week). Now, why has it taken so long? Because you can also recharge dry cells (safely!) with such a charger. Now, boys and girls, can you think why Duracell, Ever Ready et. al. might not want such a product on the market>
The second point being that NiCad manufacuters should look at perhaps two 0.75volt batters (each half-AA height) stacked, so as to get the full standard 1.5v.
Please go and learn some electro-chemistry. NiCad cells (i.e. the SMALLEST POSSIBLE UNIT of storage) produce 1.2 V, against 1.5 V for zinc-carbon and alkaline, and 2 V for lead acid. You CAN'T MAKE a 1.5 V NiCad battery. That's why NiCad 9V batteries are so poor - the cheap ones used to be only 7.2 V, with the expensive ones being more like 8.4 V. Neither were much good when you needed a real 9 V battery.
You may be thinking of U-238, aka depleted uranium. Pu238 production was done by the Department of Energy using a unusual and expensive production process, not the normal process used to convert uranium to Pu239.
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