What is Digg?Warning: The Content in this Article May be Inaccurate
Readers have reported that this story contains information that may not be accurate.88 Comments
- MikeCerm, on 10/12/2007, -1/+57The CELLs used in laptop batteries are indeed AA-size lithium-ion. They carry a voltage of 3.7V, and their capacity is usually around 2200 mAH (milliamp-hours). Other than mistaking Li-Ion for NiMH, this article is essentially correct. The batteries in laptops are a collection of these cells, wired in both series (which increases the voltage) and parallel (which increases the capacity).
The laptop companies are all very forth-right in telling you the number of cells in their batteries. Most Dell models come with a 6-cell battery, with the option of a 9-cell. HP/Compaq offers 6-cell standard also, with an optional 12-cell extended battery. What do these numbers all have in common? They're all divisible that magic number, 3!
If you wire 3 cells in series, the power output is 11.1V (3.7V x 3), but the capacity at the higher voltage is still just 2200 mAH, so you start adding addition groups of three-in-series, with each in parallel to the first. That keeps the voltage constant, but adds another 2200 mAH for each group, extending your battery life. Case in point: the 12-cell extended battery that came with my Compaq, 10.8V, 8800 mAH. It's just 4 groups of 3 (and 10.8V, because even fully charged cells never put out their full voltage).
Of course, NiMH AA's are about the same size, but the voltage 1.2V instead of 3.7V. From what we know about batteries in series, 3 NiMH would yield 3.6V. Just as can use 1.2V NiMH batteries in place of 1.5V alkaline batteries, you could also get away with 3.6V in a device that expects 3.7V.
You could probably power your laptop with AA NiMH batteries. You'd need three times as many, in series, to get the 10.8V that your laptop requires. So, my already large 12-cell would need to be a 36-cell NiMH battery just to give me the same battery life I currently enjoy. That would be huge and a real pain to carry when you consider that, despite they lower voltage, NiMH cells are actually more dense (therefore, more heavy) than Li-Ion cells.
So, forgo the NiMH replacements. For about $4 a piece you can get Li-Ion cells just like what's already in your battery. For a 12-cell battery, it would cost ~$48 to freshen up the cells in your old battery. Considering the manufacturer sells replacement batteries for $100+, it sounds like a resonable proposition. You also have to consider your comfort-level with soldering things that we all know could explode.
As for the "electronics" in the battery, often it's just the charging circuitry, and the "brains" that tell your laptop how much juice is left. Sometimes, the circuitry rejects the transplant. Unfortunately, there's no way to predict that before you get started. - imicvic, on 10/12/2007, -2/+48Aren't laptop batteries lithium polymer or lithium ion, not nickel metal hydride (NiMH)? The cells are the same AA form factor inside, but Lithium Ion has a better capacity. The circuitry in the battery controls the current to the cells, which, if I understand things correctly, depends on the characteristics of the cells, so shouldn't be placed in the laptop if a change in cell/manufacturer is an option.
- mike32716, on 10/12/2007, -0/+32Misinformed!! But partly correct. The batteries used in laptops are often referred to as "Fat A's" which are slightly larger than AA batteries. The size is dictated by international agreement for use on airplanes (safety). The voltage and amperage is a function of their density and material (NiMH or Lion).
There are numerous sites which will show you how to replace these batteries. They are indeed relatively cheap (about $4 a piece) but must be soldered together VERY carefully and there is usually a circuit board that must be "reset" as it constantly optimizes the charge/discharge cycle of the battery pack and will think it has the old batteries when the new ones are installed. As for installing higher capacity batteries that would take some research as the battery circuitry is probably set for the existing battery set. - mrASSMAN, on 10/12/2007, -4/+32http://blogs.zdnet.com/Apple/?p=279&page=3
There is absolutely no mention that the cells are "AA NiMH batteries". In fact, it says they carry 3.7volts each, which just doesn't exist in NiMH form. AA batteries only carry 1.5 volts.
I think this article might literally be a joke.
The reason the li-ion battery cells are divided up like that is because they are required to by national law in the US. It is for safety reasons. - spikes, on 10/12/2007, -1/+24NiMH Cell = 1.2V
LiION Cell = 3.7V
Big difference.
To say these are AA NiMH in todays laptops is just uneducated.
Also NiMH wont blow up and spit out flames due to a lithium chemical fire if you sneeze at it. (sarcasm) - dubloe7, on 10/12/2007, -1/+23the word 'standard' should not be used in the same sentence as 'laptop battery', or 'printer ink cartridge'. it just doesnt work.
- muaddib420, on 10/12/2007, -1/+21original source:
http://blogs.zdnet.com/Apple/index.php?p=279
i doubt there are 6 AA batteries inside the new macbooks or macbook pros. that's a 3-4 year old computer in the article. - netburnr, on 10/12/2007, -2/+20Current laptops all use Lithium Ion Batterys not Nickel Metal Hydride.
- spikes, on 10/12/2007, -1/+19Ironically those are even Lithium ION's in his example picture. (The Sony ones)
"Apple uses six Sony Fukushima US18650GR cells in the iBook battery pack. Each cell has a 18mm diameter and is 64.7mm long. Each cell is rated at 3.7V, 1800 mAh." - mrASSMAN, on 10/12/2007, -4/+16Correction to my comment: Alkaline AA batteries carry 1.5 volts, but NiMH are usually 1.25 volts.
- Grayfox777, on 10/12/2007, -2/+13Whether this is true or not, I don't think the cost of a replacement laptop battery is justified.
- LaughingMan11, on 10/12/2007, -0/+11Modern batteries in modern electronic devices like phones, notebook computers, music players, etc, are lithium ion or lithium-ion polymer.
In the 90s, NiMH was widely used as a battery technology in notebook computers until lithium ion was phased in because of better performance... however, the tradeoff was that Lithium Ion batteries were more unstable, and would spontaneously combust.
Early notebooks using lithium-ion technology, specifically the PowerBook 5300, suffered spontaneous combustion just like modern Dells and Apples have lately. Back in the mid-90s, the exploding PowerBook 5300s were a massive embarrassment for Apple, and they were forced to downgrade the batteries to NiMH for safety.
Lithium Ion technology has always been fairly flaky and dangerous. - nreynolds, on 10/12/2007, -5/+16no.
- mrASSMAN, on 10/12/2007, -0/+10Lithium is a very exotic element and it's containment on a mass scale is considered a great feat on its own. Lithium-polymer is an even more complicated battery.
Wikipedia says: "Lithium in its pure form does not occur naturally on Earth. It is a soft, silver white metal that tarnishes and oxidizes very rapidly in air and water." - drinequality, on 10/12/2007, -1/+8Buried as inaccurate. Current batteries are Li-ion.
They are dangerous beasts, catching fire or
exploding if charged or discharged wrongly.
A very good case for including some charging
electronics in the battery.
I'd say that there's a serious terrorist threat
there.... - BESTenemy, on 10/12/2007, -2/+9 The reason they put AA-looking like batteries inside is mostly due to manufacturing process. It's cheaper. Like you said, they're not exactly the same as regular rechargible batteries and voltages sometimes differ a bit - 1.2-1.4V as oppose to standard 1.5.
Has anyone ever taken a 9V battery apart? If you're not ready to crush an expensive laptop battery, then take pliers and rip the metal off. It looks like it has 6 AAA batteries inside - same form factor and each cell gives 1.5V which combined in a serial circuit gives 9V.
There are no tricks. It has to do with manufacturing plants and the way they've been evolving.
From a safety perspective, having multiple blocks is even better. If one fails and leaks, the rest remains intact. - mrASSMAN, on 10/12/2007, -10/+16This article is pure *****. That's all I've got to say.
- mrASSMAN, on 10/12/2007, -0/+5They do it because the law requires them to. Lithium packs split up into separate cells are safer.
- bob645, on 10/12/2007, -0/+5After reading this article I decided to tear open an old Sony Li-ion for an laptop I bought in 2001. Interestingly enough I found 8 cells and a small circuit board. Although the cells are round like AA they are actually much bigger. Searching for replacement cells on the Internet I can replace all 8 of them for about $16.
So in part the article is right, cheaper replacements may be found, but he failed to mention that these things are _welded_ together and not _soldered_ And the part about NiMH i just don't think he knows what the difference is.
I know my local Batteries Plus has the welding equipment available to do the job, but something tells me they are not going to charge me $15.00 to do it when they can rip me off for $130 for a new pack.
All in all, it does raise the question as to why it cost $130 to replace $16 worth of dead batteries?
Dugg for this reason, and for the excuse to take something apart. - Phil246, on 10/12/2007, -1/+6as others have said, laptop batteries nowadays are Lithium ion based, not Nickel MetalHydroxide.
really really old laptops might, say 4-5 year old ones but certainly none within the last 3 years.
Buried as inaccurate. - LaughingMan11, on 10/12/2007, -0/+5Buried as inaccurate. Those batteries in the picture in the original zdnet article are clearly sony lithium ion batteries, even if they are in the same AA form factor as you'd find in your supermarket.
$20 maybe for 6 NiMH cells, but lithium ion is more expensive, holds more charge, and is more flammable.
The article goes on to characterize NiMH as a dangerous and explosive battery technology, while compared to other types, NiMH is probably the most safe, having a tendency to put itself out when caught on fire instead of exploding. - gcauthon, on 10/12/2007, -0/+4Surprise! Your expensive laptop is expensive!
- dtfinch, on 10/12/2007, -0/+4If you break open a little 9 volt battery, you'll find six tiny 1.5 volt alkaline batteries inside. It's very common to build a high voltage battery out of a bunch of low voltage batteries, but what you find in a laptop battery is much better than a bunch of AA's.
- fhsjr, on 10/12/2007, -0/+4Does anybody else find it ironic, if not just moronic, that this guy makes fun of people who accidentally reverse batteries in poorly marked devices, then displays to all of us that:
1) He has absolutely no clue what the difference is between a Li-Ion and a NiMH battery. I'm lucky to get more than an hour out of a set of NiMH batteries in my digital camera. I'd probably get 20 minutes in my notebook, and 3 minutes if I used alkalines, which will probably be next week's suggestion. (Why don't we just go all out and pop in a dozen of the dollar store's "heavy duty" batteries? Those are really cheap...)
2) He would feel okay about taking an enclosure designed for Li-Ion batteries and filling it with NiMH batteries, then plugging it into a charger designed for Li-Ion batteries. Hopefully the charge controller would catch the problem before it blew. That is, if he didn't just throw away that useless little circuit board that was sitting in there.
What really kills me is that there has been a lot of talk in the tech sector about Li-Ion batteries for the past few months, since before Dell noticed a problem with their notebooks. Many people have been talking about them. Right off the top of my head, I know that both Patrick Norton and Leo Laporte have discussed recently the design of notebook batteries, particularly how they can be broken apart into cells not much larger than AAs due to FAA reqs. Digg has even had articles recently explaining why those reqs exist.
On top of all of this, it's obvious that Mr. Knight didn't even read his own "Further Readings." Not one of the articles he linked to gave even the slightest suggestion that the cells he was looking at were NiMH. For the record, 3 out of the 4 articles correctly identified the cells as being Li-Ion, and the fourth did not identify them as anything beyond "batteries."
I'm almost sorry to be posting such a long rant here, but it's crazy ideas like this, followed by people who can't figure out how to put battereies into their flashlight let alone their computer, that end up getting people seriously hurt and costing them thousands of dollars in property damage. People should do some research and try to understand their sources before they publish an article. We're on the Internet here, you know. Wikipedia might not be foolproof, but at least it will help you understand the technical differences between different types of batteries. - LaughingMan11, on 10/12/2007, -1/+5Apple has used Lithium Ion batteries in their notebooks for well over a decade, and if you've been paying attention, Apple recalled 1.8 million Sony based iBook and PowerBook batteries just a few weeks back.
The author's mention of NiMH is a mistake. - rebblescum, on 10/12/2007, -0/+4User _MikeCerm_ is spot on. In addition, due to the relatively high energy per density available in Lithium cells, their use, etc., is regulated, and hence rechargeable batteries are made from individual cells.
- LucasVB, on 10/12/2007, -2/+6Apparently this guy thinks just because they look like AA batteries they are AA batteries. Marked as innacurate.
- Jozer99, on 10/12/2007, -0/+3Has ANYONE noticed that he says laptops have NiMH batteries, while every laptop made in the last 10 years or so uses Lithium Ion? Mixing up the two will quite likely result in an explosion when you try and charge it.
- deadbaby, on 10/12/2007, -0/+3Nice theory but it's not true. Laptops haven't used NiMH batteries for a very long time. The inside of modern lithium ion cells do still look like AA batteries but they're far more dangerous. It's not practical or safe to have users handling the individual cells.
- rubikfreak, on 10/12/2007, -3/+6I can't say whether this is true but sometimes it feels like my school laptop runs on a few rechargeable AA batteries.
- LaughingMan11, on 10/12/2007, -0/+3Well... now it's labeled inaccurate . I'd say digg works.
- mingistech, on 10/12/2007, -0/+2yes.... this whole article is B.S.
- LaughingMan11, on 10/12/2007, -1/+3From the article:
"Can you imagine Apple trimming $100 or more from the price of every MacBook because they no longer need an expensive, over-engineered battery holder full of AA cells?
I think everyone would benefit from a move away from proprietary enclosures for industry standard batteries. How about it, Apple? "
... except that the MacBook and the MacBook Pro no longer use AA cells in their batteries like previous generations. The MacBook and MacBook Pro use Lithium-ion polymer technology that can be molded into different shapes. In the case of those notebooks, the packages are flat. Break open a MacBook battery and you'll find slabs, not AA cells.
Apple uses Li-polys instead of Li-ion in order to make their notebooks thinner, but there's also the added benefit that li-polys are less flammable. - PoserOfAllTrade, on 10/12/2007, -1/+3Go ahead and bury this comment if you want...
It's ***** like the author of this article that make me want to hunt them (people like him) down and shove a bag of batteries down their throats.
You know, KNOW he just saw a PICTURE from the original source and shat that story out without actually thinking or doing the research. Probably thinking he would be revered as cool for releasing such an important PSA.
If I could find his email address, I would send him a note just to tell him what a ***** he is. - Al3x, on 10/12/2007, -0/+2Favorite quote:
"Nobody EVERY went broke underestimating the stupidity of some people..."
The stupidity of some people who don't even read their own article for spelling mistakes... - grumpyrain, on 10/12/2007, -0/+2Li-Ion is used by pretty much all manufacturers because they have a much higher charge density than NiMH (150 Wh/kg vs 60 Wh/kg) . In simple terms, batteries can be smaller, lighter and can power your laptop for longer. Unlike NiMH batteries, Li-Ion batteries don't suffer memory effect (or at least nowhere near the same amount). They can be charged at a higher speed. NiMH batteries discharge themselves 5 times faster than Li-Ion when not used. It is not all in favour of Li-Ion though. They lose capacity regardless of the number of charge cycles. They also significantly lose capacity if in high temperatures. Of course, hardware manufacturers don't mind if batteries are dead after 5 years, as long as they can print 5 hours battery life on the package, people are happy.
Some actual facts would be useful from time to time. Honestly, if the author wishes to try and do his own AA battery substitution, knock yourself out, but a modern laptop battery is much more than a group of simple AA NiMH cells. - Bamborzled, on 10/12/2007, -0/+2You're reading the wrong article, then. Everyone was talking about the article the story gave.
- inobla, on 10/12/2007, -2/+4Buried.
The guy who wrote this has no idea what he's talking about.
Wait.. No.. Idiot. I like using NiCd and NiMH batteries for my own project circuits, but they have far less charge density than Lithium Ions... That's why they stopped using them in laptops years ago. It's the Lithium Ions that are known to explode because more care must be taken when charging them...and the batteries have to be made correctly to prevent otherwise good chargers from getting them too hot.
Takes a lot more abuse (or carelessness) on the NiCd and NiMH batteries to make them burst, but it can be done..*ahem* - randall814, on 10/12/2007, -0/+2All of you people who marked this story as innacurate are obviously uneducated in this respect. Read my whole argument, and you SHOULD see why this theory would work (assuming you have the ability to multiply numbers). To quote MikeCerm for all of you idiots that say this is inaccurate with no REAL justifications:
"The CELLs used in laptop batteries are indeed AA-size lithium-ion. They carry a voltage of 3.7V, and their capacity is usually around 2200 mAH (milliamp-hours). Other than mistaking Li-Ion for NiMH, this article is essentially correct. The batteries in laptops are a collection of these cells, wired in both series (which increases the voltage) and parallel (which increases the capacity).
The laptop companies are all very forth-right in telling you the number of cells in their batteries. Most Dell models come with a 6-cell battery, with the option of a 9-cell. HP/Compaq offers 6-cell standard also, with an optional 12-cell extended battery. What do these numbers all have in common? They're all divisible that magic number, 3!
If you wire 3 cells in series, the power output is 11.1V (3.7V x 3), but the capacity at the higher voltage is still just 2200 mAH, so you start adding addition groups of three-in-series, with each in parallel to the first. That keeps the voltage constant, but adds another 2200 mAH for each group, extending your battery life. Case in point: the 12-cell extended battery that came with my Compaq, 10.8V, 8800 mAH. It's just 4 groups of 3 (and 10.8V, because even fully charged cells never put out their full voltage).
Of course, NiMH AA's are about the same size, but the voltage 1.2V instead of 3.7V. From what we know about batteries in series, 3 NiMH would yield 3.6V. Just as can use 1.2V NiMH batteries in place of 1.5V alkaline batteries, you could also get away with 3.6V in a device that expects 3.7V.
You could probably power your laptop with AA NiMH batteries. You'd need three times as many, in series, to get the 10.8V that your laptop requires. So, my already large 12-cell would need to be a 36-cell NiMH battery just to give me the same battery life I currently enjoy. That would be huge and a real pain to carry when you consider that, despite they lower voltage, NiMH cells are actually more dense (therefore, more heavy) than Li-Ion cells.
So, forgo the NiMH replacements. For about $4 a piece you can get Li-Ion cells just like what's already in your battery. For a 12-cell battery, it would cost ~$48 to freshen up the cells in your old battery. Considering the manufacturer sells replacement batteries for $100+, it sounds like a resonable proposition. You also have to consider your comfort-level with soldering things that we all know could explode.
As for the "electronics" in the battery, often it's just the charging circuitry, and the "brains" that tell your laptop how much juice is left. Sometimes, the circuitry rejects the transplant. Unfortunately, there's no way to predict that before you get started."
Also, pay close attention to this portion of the article...in the beginning:
"Other than mistaking Li-Ion for NiMH, this article is essentially correct."
Upon revisiting the article, you will see that this mistake has been corrected. Between the information presented by the author and MikeCerm, the idea is spot on.
Also, as MikeCerm says, they are wired in series and in parallel. This is because of the manufacturing process which is DUE TO REGULATION, not cost. If this was not the case, they would throw a big chunk of lithium-ion into a battery casing, form fitted to the computer for which it is being manufactured. They know this to be unsafe, which is why it is regulated...but it would certainly be cheaper to manufacture a chunk, instead of going through a completely seperate process dividing one big chunk of lithium up into 6 or more seperated, cased, rolled, and coiled batteries.
Verdict: It would be cheaper...but would require some lithium ion AA's, a steady hand for soldering, a reset circuitry (so the computer can check the levels), a slight understanding of the mathematics and electric information presented by MikeCerm, and a bit of elbow grease. - InsaneWookie, on 10/12/2007, -0/+2I thought the reason for the 9 volt batteries being made of a number of smaller cells was because the maximum voltage from the chemical reaction was 1.5 volts so they need to connect them in series. I could be wrong though.
- redfox2600, on 10/12/2007, -0/+2Something about this reminds me of a pass digg
http://digg.com/hardware/Rebuild_your_laptop_battery_and_save_$$$_
except that was with lit-ion batteries. - inactive, on 10/12/2007, -0/+2A Lithium Ion AA sized battery is called an 18650. 3.6V.
- BigBrother87, on 10/12/2007, -0/+2The only reason they look like AA's (in a new laptop, not that old POS) is anything larger is unstable, so they are regulated in the industry. That's the biggest size that can be used safely, although they should be shielded from each other like in the Tesla just to be safe.
- jonesin, on 10/12/2007, -0/+2OK I get that the article's inaccurate, but it would be pretty cool to have a laptop that could take standard batteries.
- rspeed, on 10/12/2007, -1/+3iBook G3s used Li-Ion batteries, not NiMH.
- NATOuk, on 10/12/2007, -0/+2He does seem to spend some time making fun of people putting AA Batteries in the wrong way round and indeed suggests improvements in the shape of AA batteries to stop this being a problem.
Only thing is, it's not a problem. Any properly designed device which uses AA batteries will have protection diodes to stop the flow of current if a battery is accidentally inserted the wrong way. Such diodes costs a fraction of a penny and indeed this solution has been in place for decades - This is why your TV remote doesn't self destruct when you put the batteries in the wrong way round :p - HappyScrappy, on 10/12/2007, -0/+1randall814:
They are cells because buying cells is cheaper. Not because of regulations. Li-Poly batteries are indeed just big dallops of battery goo in a bag. Regular cells come in certain shapes because commodity devices can be sourced cheaper (see interchangable parts, Eli Whitney).
For example, the 4G iPod and Game Boy Advance SP use the same battery, in different outer packaging. The PSP uses a battery that has the same X and Y, but is thicker.
Anyway, the original summary says that the cells in your battery pack are just ordinary AAs and points out how much you're getting ripped off by them charging you so much more.
Exept they aren't ordinary AAs. Often they aren't AAs at all. So of course they aren't priced like AAs.
The article is inaccurate in the area of the point it is trying to make.
And you have shown you don't understand battery packs too. - ismith, on 10/12/2007, -7/+8Once in a while you might get a hold of NiMH batteries. I think this was a G3 iBook, so it's from around 2001... (not positive though). My iBook G4 battery is NOT the same as this though, otherwise there's no way I could have smashed it in the way I did (Sorry no pics). So really, the title should probably be "Surprise! Your five-year-old consumer grade laptop battery is just 6 AAs and some circuitry". Also I was unable to find the original source from ZDNet.
- netburnr, on 10/12/2007, -0/+1I'd say thats a pretty good rundown...
Move along, nothing to see here //mackey voice - HappyScrappy, on 10/12/2007, -1/+2Naw, they're LIons. AAs are 1.2V and thus cannot be LIons.
Laptop batteries may be lithium polymer, but then again they might be Lithium-ion in AAs, As, 5/4As (25% oversized As) and in the old days, sub-Cs (which are Cs that don't have buttons on each end and instead are welded directly to).
And the circuitry is very important in preventing problems during charging, as LIons and LIpolys are very sensitive to conditions when being charged, much more so than NiMHs.
Marking as inaccurate. -
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