Author: matthew

Warning: Science ahead! Close your eyes and turn away, you’ve been warned!

Many radio-control enthusiasts experience disappointment with the cycle life of their Lithium-based batteries in electric aircraft. Often this is because they’re not entirely sure what’s going on inside the battery, and choose a capacity or voltage that’s inappropriate for their application. Ultimately, this manifests itself in “swelling” or “ballooning” of a Lithium battery. This editorial attempts to explain what’s actually going on when this happens.

Chemically, there can be three causes for the swelling of a LiPo battery, and one exacerbating condition that makes it worse across the board. These occur in hard-shell Lithium Ion batteries, too, but the hard shell can withstand several atmospheres of pressure before expanding.

Note: This is MY understanding of the chemistry involved. I may be off-base, after all, I’m a college dropout. But I did love chemistry class!

Cause #1: WATER in the mix.

EDIT: Lithium manufacturers who’s products are implicated in this assertion (read: Hextronik et al, circa 2006-2007, Thunder Power circa 2008) will dispute the assertion of contaminated Lithium. The most common contaminant is water, but there are many others that will cause lithium oxidation in the cell. Basically, any other substance containing oxygen that can be freed by electrolysis or heat will become a contaminant, and any substance that isn’t the expected anode, cathode, or separator is a contaminant that will reduce the performance of the cell and cause swelling in other ways. Manufacturers have a fiduciary responsibility to claim that there was no product defect, otherwise they’re responsible for a recall. I’ll talk about the science and let you draw your own conclusions.

This was the common problem with many cheap Chinese LiPos of around 2005-2008. Most are better now, but it’s the #1 cause of premature LiPo failure: water contamination in the plant. Many of China’s LiPo factories are on the coast, where the altitude is very low and the humidity is high. You can’t run the humidity too low on the assembly floor, because you’re working with volatile chemicals that could explode in the presence of a spark, and you can’t run it too high because then you end up with a worthless LiPo that swells on first use.

Here’s the science. You have three ingredients that are functional in a LiPo battery. The rest is wrapping and wiring attachments.

• Cathode: LiCoO2 or LiMn2O4
• Separator: Conducting polymer electrolyte
• Anode: Li or carbon-Li intercalation compound

I’m going to be a little vague in my language here. The chemicals involved vary according to manufacturers, so I don’t want to make any assumptions.

Remember your chemistry class? Note the absolute lack of any hydrogen atoms in the reaction. None, zero, zip, nada. If you have water inside your battery — and virtually all batteries have a little bit — you’ve got problems. When the chemical bond of H20 is broken by electrolysis and heat, you end up with free oxygen. You also have free-roaming hydrogen that typically ends up bound to your anode or cathode, whichever side of the reaction it’s on and depending on the state of charge of your battery.

Now, this is a pretty unstable situation that’s exacerbated by any over-discharge or over-charge condition creating metallic lithium in your cell. The end result is Lithium Hydroxide: 1 atom of lithium, one atom of hydrogen, and one atom of oxygen.

But you still have a free oxygen atom floating around inside the battery casing, that typically combines with one other oxygen atom — O2, or what we sometimes think of as “air” — or two other oxygen atoms, to form a characteristic tangy, metallic-smelling substance called “ozone”, or O3. Gases expand with heat and contract with cold. Chuck a swollen battery in the freezer and it might come out rock-hard again… until it heats up. It’s not frozen, it just got cold enough that the gases inside didn’t take up much space at all.

And that free O2 or ozone is just waiting to pounce and oxidize some lithium on the slightest miscalculation on your part. The modest over-discharge during a punch-out, or running the battery a little too low or letting it get a little too hot, or running the voltage up to 4.235v/cell on a cold day when the actual voltage limit per cell is more like 4.1v. All of these create the perfect storm for a puffy battery to quickly turn itself into a ruined battery or an in-flight fire.

Understanding the role of free oxygen in your battery, from water and other causes, is CRUCIAL to understanding why batteries fail, and why sometimes you can get by with flying a puffy battery, and sometimes you can’t.

Cause #2: Formula degradation from over-charge/over-discharge

If a Lithium battery is overcharged or charged too quickly, you end up with LOTS of excess free lithium on the anode (metallic lithium plating), and free oxygen on the cathode. A free oxygen atom is small enough to freely traverse the separator without carrying an electric charge, resulting in lithium OXIDE on the anode. Lithium “rust”, in reality. Useless to us at this point, just dead weight being carted around inside your battery’s wrapper.

But lithium oxide uses fewer oxygen atoms than existed in the ionized state, so you end up with, again, FREE OXYGEN. And people wonder why if you over-charge a LiPo underwater, it still ignites despite the lack of open air…

If it’s over-discharged or discharged too quickly, the reverse is true, but you end up with Lithium Oxide on the cathode, but at a lower rate because there’s simply less there. Basically, an abused battery quickly develops corrosion on both poles of the battery inside the wrapper. And the more it’s abused, the worse it gets as the resistance goes up and it still gets driven hard.

This, by the way, is the most common cause of swelling today for our aircraft when flown with a high-quality pack (not knock-off eBay leftovers from expensive Chinese mistakes of 2004-2009). The reality is, these kinds of cells, regardless of their ‘C’ rating, are built for use where they last for several hours… not several minutes. While the chemistry if used as designed is good for thousands of cycles, we’re driving them so far out of spec that we’re lucky to get hundreds of cycles out of them.

In most cases, too, our batteries are under-specced. If slow-charged and slow-discharged, many of these packs would often hold considerably more mAh than we think they do. That’s one of the reasons we get the performance we do from them. Higher-C-rated packs also often introduce gelled electrolyte into the separator, and carbon or phosphorous nano-structures on the anode and cathode mixtures rather than the “pound it out thin and hope it’s mixed right” approach used with sheets of anodes & cathodes today.

Cause #3: Poor separator construction

A number of cheap LiPos also use a bad separator formulation. Ultimately, it often boils down to using a dry separator with way too high of an internal resistance to hold up to manufacturer “C”-rating claims. The internal resistance grows over time because a higher and higher percentage of the LiPo is simple Lithium Oxide, and the balloon grows bigger as more oxygen atoms are freed.

I’d also lump “poor anode or cathode chemistry” into this category, too. Ever get a bad battery out of a batch of good ones? Often it’s because the mixture of chemicals was inconsistent, and you end up with too much or too little lithium on one side of the battery (well, in certain plates, you get my drift).

Exacerbating factor: HEAT.

A little heat makes everything work better for a Lipo. If you could fly your battery right at 140 Fahrenheit all the time, it would make fantastic power and be operating right in its happy zone. But it generates heat when charging, and when discharging. Hitting 150 results in significant metallic lithium generation, which as we can see from above is a major cause of puffing and cell destruction.

Similarly, the maximum 4.235v/cell limit is only at that mythical 140F. It goes down steadily from there, to about 4.2v/cell at room temperatures, and around 4.0v/cell below 50F, beyond which the over-abundance of electrons will again break chemical bonds and free lithium to bond with oxygen and create lithium oxide… which is just a disaster waiting to bond with humidity in the air if the LiPo ruptures, to create Lithium Hydroxide.

Conclusion

Chemically, there are no LiPos that will not puff under certain circumstances. But tightly-controlled humidity, a superb gel separator, nano-structured anode and cathode, and careful charging and discharging within manufacturer limits should also prevent puffing. Similarly, putting a pack that has been abused into a lower-discharge aircraft, even when puffed, often serves the purpose of stopping the puffing in its tracks because no more metallic lithium is being created in the cell by abuse.

And now you know the answer to today’s geeky topic. Why lithium polymer batteries often puff up.

My brother Jay posted a great story we watched on Sunday: Old 666. Excerpt:

Zeamer and his misfit crew seized the plane, and worked to restore it and make it airworthy again. Not just restore it – they decided to customize it. They added nearly 50% more guns to the bird, including a forward-firing machinegun so Zeamer could also shoot, like a fighter pilot. They replaced the .30 caliber machine guns with bigger .50 caliber guns – or, in some cases, twin .50 caliber guns. When they were done, their aircraft – number 41-2666 (or 12666, depending on the account) was the most heavily armed bomber in the entire Pacific theater of World War II.

They never added customary nose-art to the bomber, leaving it unadorned. So it became known by its serial number on its tail – “Old 666.”

These guys were nicknamed “The Eager Beavers” because they consistently volunteered for the most dangerous, crazy missions. They’d frequently come back shot full of holes, but they made it home. Zeamer and crew of renegades gained a new reputation for courage and incredible airmanship. In one night mission, for example, the enemy troops managed to fix the entire flight of bombers with large searchlights, illuminating them so they could be shot down by anti-aircraft guns. Zeamer used his giant aircraft as a fighter, diving on the searchlight positions and using his forward-firing machine guns to destroy three of them and damage two others, saving the other planes and their crews…

Check out the rest of the article. Jay even has a link to the History Channel documentary on Old 666 and its renegade, typecast crew of misfits who really existed. Why hasn’t this been made into a movie, anyway?

Be careful about blowing your Vuvuzela at your dog in the house.

Just ran across a great tutorial on how to use the Pingback module for Drupal.

I’ve been a little bit out of the latest tools for blogging & social media lately, and Pingback as a replacement for Trackback is a really good idea. Basically, it’s Trackback with a vengeance: it forces that the site placing the pingback actually link to the article in question, and places limits on the number of links available on the destination pingback. Pretty sweet!

Ultimately, controlling spam while publicizing a site is one of the great challenges of running a long-standing blog. The spammers attack, and attack, and attack, wearing you down. I plan to implement this pingback utility just as soon as I get the spare time to update my Drupal install, too.

I’ve recently begun doing some research into how I can improve traffic to my web site. Yeah, I know, long-term readers would say “Uh, dude, start writing again!” I hear you, and I’m working on it, starting today here & now.

One of the sites discussing driving traffic to blogs mentioned one of the basics is being aware of “hot keywords”, where advertisers pay top dollar for click-through ads. Now, a lot of these, I feel like I’d have to sell my soul to capitalize on them. I’m talking about the ads for cheap viagra & cialis, payday loans, debt consolidation, and Nutrisystem eating plans. Well, OK, Nutrisystem is just a diet plan under the hood – and a well-advertised and above-board one at that – so I guess I’d be OK about that, but the rest seem to be largely the province of people who constantly try to spam my site with comments to try to boost their ad revenue, offshore pharmacy, or extortionate loan scheme.

I feel as if I need a shower just after mentioning those keywords! The people who hawk them online using spammish techniques are just that scummy that I can get second-hand scumminess by just saying the words they try to abuse.

One that stood out to me, though, was the huge number of links for people asking about how to buy a substance called “Tramadol”. I’d never even heard of this stuff before yesterday. So, as usual, I hit the web to do some research and figure out what’s going on. Like most things, you can find out the basics from Wikipedia. Tramadol is an analgesic for treating pain. People use it for a wide variety of pain-related therapies. Side effects include nausea, diarrhea, headache, sores, difficulty breathing, seizures, and hallucinations. Why would someone want to take this stuff unless they absolutely needed it for managing pain?

In the description I found the answer that immediately stood out to me amongst the sea of other uses: “Premature Ejaculation”. You see, from long experience being the victim of spammers on the Web, I’ve learned that there are at least a few people are willing to pay top-dollar for anything that “enhances male performance”. From Viagra to Cialis, and now apparently to Tramadol, men seem to believe that lasting longer in bed, being better endowed, or otherwise enhancing their maleness will get them the babes.

Unfortunately, that these substances will solve the problems in your love life is a lie that the drug companies would like to you to believe.

And this relentless focus on self-medication – particularly, non-prescription self-medication from offshore pharmacies – really bugs the heck out of me. Do you guys have any idea how dangerous it is to try to buy this stuff from the kind of place that would sell it to you without a prescription? If you really need Tramadol to manage your pain, by all means, go see your doctor, have it prescribed in an appropriate dose, and have it filled at a reputable pharmacy. But if you’re self-prescribing it to try to last longer in bed, you’re taking a huge risk with your life, sanity, and health.

The reality, men, is that if you’re really wanting to do well with women, you need to learn how to be the man that woman is really looking for. Working on your level of physical fitness helps make you more appealing – that’s a topic for another entry later – as does improving your mental acuity and sense of humor. Most women’s needs, though, are not usually for a guy with the biggest muscles or longest schlong. That’s a myth perpetuated by the adult film industry, among others. Most are looking for the guy who knows how to meet her emotional needs. A guy who knows how to seduce a woman by appealing to those needs. And usually, those needs aren’t what the women say they are. And they aren’t what the pharmaceutical companies want you to believe they are, either.

Educate yourself to be the man of her dreams. Don’t medicate yourself into oblivion.

Because I’ve started writing my soliloquies again, I’ve changed permissions again for new users. Anonymous users are allowed to post again, as are recently-authenticated users, but all posts are moderated unless you’re part of the “Contributor”, “Barnsons”, or “Moderator” groups.

There’s only one moderator besides me. If you’re an honorary Barnson, you know who you are. There are no Contributors yet… those will be any folks who I don’t want to be able to host a blog here, but who are active enough to warrant posting without moderation.

Also going through and deleting massive numbers of spam accounts from my system. At a rate of approximately 6 to 10 new spam accounts per day since 2001, the user database has gotten huge.

Found this article in my local online rag this morning.

TALLAHASSEE, Fla. (AP) — Attorneys general from 13 states — including Utah Attorney General Mark Shurtleff — sued the federal government Tuesday, claiming the landmark health care overhaul is unconstitutional just seven minutes after President Barack Obama signed it into law.

This is the same Attorney General who claims we don’t have the resources to enforce the Utah State Constitution, yet we somehow magically have the resources now to take up a challenge to the first bill — the first few baby steps — to reform the horribly broken, incredibly expensive bureaucracy that is the US healthcare system?

I understand that, without a public option, this amounts to an unfunded mandate like No Child Left Behind. And that execrable act at a cost of around $30Bn a year, leaving $9Bn a year to be made up by the states, still never received as much criticism as this one.

“The Constitution nowhere authorizes the United States to mandate, either directly or under threat of penalty, that all citizens and legal residents have qualifying health care coverage,” the lawsuit says.

Legal experts say it has little chance of succeeding because, under the Constitution, federal laws trump state laws.

Let me get this straight. I’m in good health. My kids are in good health. My wife is in good health. As a taxpayer, I’m already funding health care coverage and retirement for America’s over-fifty majority through FICA, and capped my Social Security benefits years and years ago… I will never see a dime of the $13,500 max (EDIT: Uhh, that’s changed. It’s over $15,000 as of 2010) the federal government is allowed to take from me every year. My employer pays $700 a month for my health insurance, and I pay $810 a month for it. So the total cost of health insurance — not including dental, vision, and life insurance — is over EIGHTEEN THOUSAND DOLLARS A YEAR. Add that to FICA — which is really just a big, charitable donation at this point — and between the Feds and the insurance monopolies, I am out potentially over $30K a year.

Thirty. Thousand. Dollars. To pay for somebody else’s retirement, somebody else’s health care, and oh, by the way, a few hundred bucks of health care for me and my kids every year.

My employer refuses to give me a raise. Know why? The rising cost of health care, they tell me, IS my raise. And the amount I’m paying for health care DOUBLED over just the past nine years. We have to do SOMETHING to curb this crisis, and I’m just happy to see someone have the constituency and courage to finally get started on the process.

Then the AG for my state gets a bug in his butt to kowtow to the insurance company lobbyists, and here we are. I’m already subsidizing someone here. In my point of view, all this bloody bill does is show the average taxpayer who it is they’re paying for.

In Michigan, the Thomas More Law Center of Ann Arbor, a Christian legal advocacy group, sued on behalf of itself and four people it says don’t have private health insurance and object to being told they have to purchase it.

You know, I get this part. The Feds mandating that every American buy private health insurance is a little bit grating. We should really have a low-cost, minimal-coverage public option that everybody could pay for if they don’t have other coverage.

Oh, wait. The right wing and insurance lobby killed the Public Option. Now they are the ones grousing about not having a public option. What the heck?

But I kind of see the point now. See, without a Public Option, this bill is an absolutely enormous win for the insurance lobby. Now everybody HAS to have insurance! What a marvelous recruiting opportunity for insurance companies!

The lawsuit claims the bill violates the 10th Amendment, which says the federal government has no authority beyond the powers granted to it under the Constitution, by forcing the states to carry out its provisions but not reimbursing them for the costs.

Right. Just like NCLB did. And all these Attorneys General lined up to block that pig-headed, anti-education mandate under George Bush, Jr.

Oh, wait. They didn’t.

Other changes would not kick in until 2014.

That’s when most Americans will for the first time be required to carry health insurance — either through an employer or government program or by buying it themselves. Those who refuse will face tax penalties.

“This is the first time in American history where American citizens will be forced to buy a particular good or service,” said Nebraska Attorney General Jon Bruning, explaining why his state joined the lawsuit.

Actually, untrue. We are required to purchase auto insurance if we drive an automobile. We are currently required to purchase health insurance if we don’t have the cash to pay for huge medical bills out-of-pocket, bills that are so huge because we’ve already been forced to fund emergency-room visits for uninsured individuals and fund huge lawsuits which are the legal community’s equivalent of winning the lottery.

Why not insurance-industry reform instead? Let’s have some oversight over the out-of-control insurance industry that charges extortionate sums and refuses to cover many of the claims. We know now that the past forty years of incredible rise in medical costs can be laid at the foot of the insurance companies, not technology or litigation.

Oh, that’s right. We can’t reform the insurance industry. They are making unheard-of profits, and own most of our politicians. That’s the only reason the current health-care bill saw the light of day: because despite the hugely-divisive nature of health care reform, this one is just enough of a sweetheart deal for the insurance industry to buy key politicians who might have considered voting against it… or voting in some other reforms.

Can you tell I’m ambivalent about this bill? I’m optimistic, but given that the public option was excised from the bill in order for it to pass, I look at it now as more charity for the bloated, unproductive insurance industry… and we need to fix that as soon as possible.

Until today, I have largely ignored the Tea Party. Decided to read some of their own literature today. After careful study, I’ve come to the conclusion that it’s a mostly-male thinly-veiled white-supremacist organization hell-bent on eliminating religious freedom from the USA. Apparently some 11% of the USA sympathizes with them. Yuck.

Here are a few specifics I’ve discovered in my half-hour of skimming their stuff. Note that I’ve had practically no exposure to their party up until now… I heard about a few poorly-attended rallies and people buying tea to throw into local harbors, but just kind of brushed it off. However, they made one of the front-page links of CNN because they are considering the creation of a third major political party in the US. Facts I learned:

• 6 out of 10 members of the Tea Party are male.
• After extensive Googling, I have never seen a photo of a black member of the Tea Party.
• Around 40% of Tea Party members are retirees.

I found a few more interesting things reading their “Declaration of Redependence”, a re-write of the Declaration of Independence with modern-day Christian sensibilities rather than the Founding Father’s Enlightenment principles:

Free-market Solutions for Healthcare Reforms, Entitlement Program Reforms, Education Reforms Are Needed – Failure of our leaders to find free market and spiritual based solutions for these human needs cause citizens to flirt with compromising God’s 5th through 10th behavioral mandates. Attempts to leverage human needs and suffering and the redistribution of wealth for political power or personal enrichment has its roots in the breach of Gods first three Commandments.

Wow, do I have a number of concerns with this statement. First, they are saying that by not finding a “free market and spiritual-based solution”, political leaders are violating commandments 5 through 10. Assuming we’re talking about the Commandments in Deuteronomy 5:6-21, those commandments are:

17 You shall not murder.
18 Neither shall you commit adultery.
19 Neither shall you steal.
20 Neither shall you bear false witness against your neighbor.
21 Neither shall you covet your neighbor’s wife. Neither shall you desire your neighbor’s house, or field, or male or female slave, or ox, or donkey, or anything that belongs to your neighbor.

So a public option for health care, according to the Tea Party, will cause you to flirt with murder, adultery, theft, perjury, and covetousness. OK, that sounds fairly whacky to me, but now I know where they stand.

This document gets weirder.

Judicial Reforms Are Needed – The unconstitutional legislating from the judicial bench, establishing immoral precedents and ignoring the original intent of the US Constitution. Judicial arrogances prove a complete contempt for Gods first three Commandments and selective disregard for our Creators 5th, 7th, and 10th directives, while facilitating their erosion.

So, apparently, it’s time for “out with the old, in with the new”. Let’s throw out the checks and balances and go with, I don’t know, say, the Divine Right of Kings instead? Apparently, to the Tea Party, this is the new ideal: No judiciary!

What a grand idea! No check on legislative powers! Why didn’t the Founding Fathers think of this? We should ensure there are no powers to review a new law — however poorly imagined or implemented — other than how the Chief Executive chooses to implement it. Genius!

Seriously, though, I think the Tea Party folks are sore about Roe V. Wade. Apparently the Tea Party is unaware of the Constitutional Amendment process. I believe that is supposed to be the ultimate balance against judicial impropriety, and in fact we as a country have used it a number of times.

In fact, at least once in modern history we squeaked through an amendment banning alcohol from coast to coast. It took over a decade, but eventually we the people realized what a stupid idea that was, how much crime it created, what a dramatic reduction in quality of life it created, and we repealed that very bad, poorly-thought-out amendment. Since that time, we’ve been extremely cautious about passing amendments. So cautious, in fact, that despite the very loud outcry from Pro Life activists, an anti-abortion provision in the Constitution has never seen the light of day.

It’s not a conspiracy. It’s that you need overwhelming support to pass a law overturning the judgment of the Supreme Court. And apparently Americans aren’t yet willing to throw their rights under a bus driven by the whims of their state representatives. The day they are, rather than the Tea Party trying to eliminate the power of the Judicial branch of the American Government, why not have a big rally and start the kick-off party for your Constitutional Amendment banning abortions in the USA?

Heck, make it a celebration larger than any the world has ever seen. Maybe you’ll drive those leftist, commie-pinko Liberals to emigrate to Mexico or Canada where they’ll get their monthly abortions in the mail alongside their latest episode of “The Nation”.

America’s Judeo-Christian Spiritual Foundation and Responsibilities of American Citizens Recognized – Disrespect for our God and Creator, His Words in the Holy Bible and the Ten Commandments, His imprint upon our founding documents plus the assault on the traditional family and life issues moral decline in our society, contributes to the loss of our principles, values and Common Sense. Our current government leaders and judiciary revel in the violation of Gods first three Commandments and cause our citizens to be in frequent conflict with His other behavioral dictums.

Which God? Zeus? Thor? Allah? JHVH? The Great Mother?

Here’s where the Tea Party totally lost me. This nation was founded by many religions and by Enlightenment thinkers who understood that the “Divine Right of Kings” was absolutely a wrong approach to government. The power of government, to our Founding Fathers, derived not from God, not from the Bible, not from the Commandments, but from the PEOPLE. The Founders understood that to fairly govern, the government must first and foremost look after the people, not any specific religion. They wanted most of all to depart from state-sanctioned religion as experienced under the oppressive hand of England.

The Founders got their wish. Now the Tea party wants to force the US government to bow its knee to their God. We, the people, are the government; its officials are only our representatives. I would no more force my Muslim neighbor, my Hindu neighbor, or my Jewish neighbor to kneel before the Christian god than I would force a Christian to bow to an idol of Shiva.

So there you have it. Ultimately, these kinds of statements cast no doubt that the Tea Party is nothing but America’s Taliban: religious extremists hell-bent on seeing their interpretation of Christianity shoved down the throat of every American.

Whether we want it or not.

Updated Drupal today to version 6.15 from 5.X. No issues at all, it went perfectly. Not entirely sure I want to re-enable all the old modules. But I am sure I want to start writing in this dang thing again. It’s been months since I’ve posted due to some personal reasons. Yet the compulsion to write is hitting me again!

Got a question from a relative the other day: “Why are SSDs so much smaller than hard drives?” Here’s my layman’s response:

A hard disk has several spinning platters. It is one of the most common failure points in a computer because it is a moving part. It’s the thing that gets replaced the most in my data center, followed closely by fans. If you eliminate those two failure points, you eliminate a lot of problems. Spinning hard disks also get quite hot due to friction and the motors involved in spinning the platters, and if you drop your laptop while the hard drive is spinning madly at 4500-10,000 RPM, it’s likely to get damaged. Hard drives are also noisy, between the noise of the spinning itself and the motors moving the heads.

Solid-State Disks, on the other hand, are perfectly quiet and have no moving parts. However, they are “memory”, and not a hard disk. The manufacturing process is completely different and much more expensive per gigabyte at the moment than hard disks, but they also have much, much faster “seek times” since a head doesn’t have to be moved by a motor to read or write to a sector. A typical USB flash drive is around $2 per gigabyte today, while a hard drive is around $0.10 (10 cents) per gigabyte (late 2009 prices).

So what are the advantages to having a SSD in your notebook instead of a hard drive? * Totally quiet * Creates less heat * Usually takes less power, resulting in longer battery life * Less likely to lose data during rough handling * Higher reliability across the board * Extremely fast “seek times” looking up data (no heads to move into position first). * Will get faster/larger in the future for the same dollar due to market demand

Disadvantages vs. a hard drive * Smaller capacity per dollar * Despite faster seek times, often no faster on sustained reads than a hard drive * Limited read/write cycles (typically a few hundred thousand before parts of the SSD are dead, though manufacturers work around this in various ways) * Cheap SSDs often have far worse performance and power requirements than comparable hard drives (varies by manufacturer)

Eventually, I see a day when virtually all portable computers will ship with SSDs instead of hard drives due to their rapid improvements and dropping prices. And, in truth, a single 20GB drive holds all the “stuff” I use day-to-day. Extra capacity beyond that is music, movies, and other storage-hogging material like my home studio recordings. Basically, at this point whether you go with SSD or a hard drive boils down to “how much storage do I need in my notebook?” which is typically dictated by whether you’re big into movies and music on your computer or not.

Good luck in your search!

Regards, Matt