Slatterz writes "Toshiba has unveiled a battery prototype that offers a 90 percent charge capacity in just 10 minutes. The Super Charge Ion Battery (SCIB) is capable of handling 5,000 to 6,000 recharge cycles, compared to the typical 500 offered by standard lithium-ion batteries. The new battery is composed of a durable material that offers a high level of thermal stability and prevents overheating."
Let's use Australian numbers (because I know them):
Available voltage from a standard wall outlet: 240v
Available amps: 10
Using Ohms law (and assuming resistance will remain roughly the same), I should be able to get nearly 100A @ 24v using a step-down transformer. Most laptops have an input of around 19v. As long as the leads can handle the amperage, it shouldn't be an issue.
It's the leads that will be an issue. IIRC, cars need 50-80A @ 12v to start. The leads that come off the battery for the starter motor are pretty big, and they only need to handle that current draw for up to 10 seconds...
Actually it's quite a bit more than that in a car. You'll see a good 3-500 amps and more depending on engine size, age, temperature and other starting conditions.
In fact, batteries are rated in cold-cranking-amps - i.e. the number of amps they can supply to start the car while cold (probably around freezing, not sure of the exact temp measured at). A hefty battery is rated somewhere around 8-900 CCA.
You're right though - the wiring only needs to support that load for ~10 seconds in a worst-case situation so the conductors don't have to be as heavy as they would otherwise.
The wire gauge needed for some application is determined by current; voltage only matters to the extent that the insulator around the wire needs to be thick enough to avoid dielectric breakdown. A power cord that carries 30A at 240V uses the same wire gauge (10 ga., IIRC) as one that carries 30A at 120V, but the thicker insulation on the 240V cord makes it a bit larger. 100A through some 24-ga. hookup wire will burn out just as fast at 1V as it will at 100V or 10kV; the higher voltages might make for bigger sparks when the wire finally melts, but the resistive heating of the wire is proportional to the square of the current.
This is basically the same technology AltairNano uses -- a traditional LiCoO2 cathode and a nanotitanate cathode replacing the traditional graphite one. In large format, you get 70-80Wh/kg. It's a little better than NiMH in that regard, but not much. It's also a lot more expensive (AltairNano's are $2/Wh; hopefully a heavy hitter like Toshiba can bring prices down). Where the chemistry shines is everything else. It's incredibly stable, rapid charges, handles a very wide range of operating temperatures, has a ridiculously high power density (~5 kW/kg), fire resistant, highly efficient, and so on down the line.
It's one of a variety of relatively new, commercially available li-ion chemistries, each with their own strengths and weaknesses. When you hear of lithium ion battery packs in electric vehicles, with the exception of Tesla, they're usually these new chemistries, not traditional LiCoO2/graphite cells. The next-gen chemistries look even more impressive, but we'll have to wait for them;)
Looks great for "micro-hybrid" cars that use only a small battery for recovering braking energy and a boost on accelerating. In these applications, you need a lot of power density. Or simply as a starter battery (good bye lead-acid).
For plug-in hybrids or electric only cars, LiPO4 is also interesting: somewhat higher energy density, and the lower power density is not a problem due to the larger battery. An example of a system that seems to be commercially available: http://www.valence.com/products/epoch_overview.html [valence.com]
SCiB batteries can endure 5,000 to 6,000 recharge cycles, compared to around 500 cycles for standard lithium-ion batteries, according to a Toshiba executive manning the company's booth at the Ceatec exhibition in Chiba, Japan.
At the show, Toshiba showed a prototype SCiB battery installed in a Dynabook laptop. The laptop was matched
only 500 cycles, really? that seems a little low. do they mean that after 500 charges the battery begins to decrease in capacity, or that the battery will start to fail completely after 500 charges? because that seems really really low to me.
i mean, most rechargeable batteries today are Li-ion batteries, right? i just wanna know how many recharges i have left on my PSP.
does it help if you make sure to plug the battery back into the charger before it's out of charge? what can you do or not do to help preserve the capacity and life-span of a li-ion battery?
I think it's pretty close - at a rough educated guess, I'd say that after 500 cycles without disciplined use (see below), you'll be around 30% of factory capacity. (I'm assuming a cycle every 1.5 days)
Supposedly keeping the battery between 30% to 70% charge is helpful; there are utilities for this for laptops, don't know about PSP. Running it all the way down is very bad, and when I got lazy about it, my battery life did plummet (though it may have just "aged" independently, it seems connected).
hrm... well i guess it's a good thing that i've only let my battery die once or twice since i got it. with replacement batteries costing $40~50 a piece, i'll have to be more attentive about my charge state.
i seem to remember seeing several different stories on/. about "revolutionary" new battery techs, but i still haven't seen any alternatives to traditional li-ion batteries being sold at commercial retailers. IMHO lithium-titanate [wikipedia.org] batteries look promising. manufacturers are claiming that these new lithium batteries can recharge in under 10 minutes--and that's for use in electric vehicles. this New Scientist article [newscientist.com] reports that mobile devices using lithium-titanate can recharge in 6 minutes, and each battery is capable of going through 20,000 charge cycles.
i'm guessing this technology is probably still too expensive to bring to market. it'll probably only be used in electric vehicles or other such applications which require much more durability and longer life-spans than traditional Li-ion batteries currently provide.
Those are 500 FULL cycles. Use 33% of the battery one day, recharge, 33% of the battery the next day, recharge, and 33% of the battery the next day, and recharge, and you'll bascially have used one full cycle.
>>>Use 33% of the battery one day, recharge, 33% of the battery the next day, recharge, and 33% of the battery the next day, and recharge, and you'll bascially have used one full cycle.
Nope. You see, batteries are a lot like dogs. If you overfeed your dog, he won't live long. If you underfeed you dog, that too can shorten his life. If you alternate between stuffing your dog full of food, and then not feeding him for a whole week until he's skin 7b ones, that too can damage him due to the stress
The benefit of Li-Tit (SCiB) is not density, it's charge time. Li-Tit batteries reach 80+% charge in 90 seconds. Yes, some other batteries hold more charge per volume or charge per weight, but Li-Tit batteries have a MAJOR advantage in automobile use where volume is not as much of an issue as charge time.
The Li-TiT (SCiB) batteries first of all are old news, and I don;t know why this is on/. now. It;s not only old news as far as science, it's old news as in they've been sold on the open market in large
Supposedly keeping the battery between 30% to 70% charge is helpful; there are utilities for this for laptops, don't know about PSP.
Somewhat offtopic, but I've been wondering about this: my main laptop is currently also my main desktop. As such, while I run it off the battery every now and then, it's plugged in most of the time. Does this have a negative effect on the battery life? Should I use the battery more often?
It's definitely not ideal. If you keep it in your laptop, it's going to be much warmer than room temperature (because the laptop is warm) and fully charged.
To summarize the above page, it's best to store a battery a bit less than half-charged, and not above room temperature. So to preserve your battery when you really need it, take it out.
only 500 cycles, really? that seems a little low. do they mean that after 500 charges the battery begins to decrease in capacity, or that the battery will start to fail completely after 500 charges? because that seems really really low to me.
i mean, most rechargeable batteries today are Li-ion batteries, right? i just wanna know how many recharges i have left on my PSP.
does it help if you make sure to plug the battery back into the charger before it's out of charge? what can you do or not do to help preserve the capacity and life-span of a li-ion battery?
Li-ion batteries are usually limited by 'calendar' life, not charge cycles - they start losing capacity the moment they are packaged at the factory and generally last a couple of years before they become too weak to use.
However, there are some strategies to extend their life:
1. Keep them cool (but not frozen) 2. Keep them at around 40% charge
Now, this probably isn't too useful for batteries that you are actively using - however, if you have spare lithium batteries lying around that you aren't using at the moment you might want to drain the charge to about 40% and zip them up in ziplock bags and put them in the fridge until you need to use them (check it once in a while to make sure they haven't drained to zero charge because that can kill them).
Also, this means that you should avoid letting your Li-ion batteries get hot unnecessarily, like leaving them in a hot car in the summer.
I'm increasingly sceptical of EEStor. They've just signed another "worldwide exclusive" deal with a tiny company called LightEVs for all 2 and 3 wheel vehicles. The deal they did previously with Zenn covers all small to midsized cars so they've now conceeded a big chunk of their margin to a couple of nobodies. You've got to wonder - how are these companies adding value? What's their track record? Why hasn't EEStor made deals with more established manufacturers? A single working prototype which has the perfo
But they have a drawback: Only about half the energy density compared to normal Lithium Ions.
Not to mention that in order to really charge them that fast, you will need a much higher rated, and thus bigger/heavier PSU brick for the notebook...
On the other hand, this is only (to become) the first commercial version of this battery. Give it a few years and we might be seeing promising things.
Having said that, I don't think this product is directly targeting the laptop industry. For starters, as you mentioned, it requires more space. Secondly, when and if it gets commercially available for laptops, we'll be seeing fuel cell batteries as well. They offer more performance and that instant recharge factor as well.
What is the purpose of giving us the time to charge to 90%? Is there something about the final 10% that takes longer to charge than the rest of the battery?
Or are they charging while running - and perhaps not able to get all the way to 100%? The article was lousy (to be generous) and doesn't say what it would take to reach 100%.
Yes, there is: Typically, the last few % take a as long as everything before together. Its just that the nature of the chemical reactions involved: During the charge, the battery voltage increases. The charger OTOH cannot push more than 4.2V (for normal batteries) respectively 3.7V for LiFePo4, in order not to damage the cells. This means that effective voltage drops during the charge, and duringe the last bits of capacity, there are only some 0.1V left. Add internal resistance, and its clear why it cannot fill up completely fast
Other comments suggested downrating, but that doesnt really make sense: as long as you leave it in the charger, it will gain charge for a while, so the real capacity is truely higher.
It's based a long-standing rule of project cycles, known as the 90/90 rule: the first 90% of the project takes 90% of the time, and the last 10% of the project takes the other 90% of the time. Or at least that's how most software projects seem to end up...:-)
If you think of a battery as a bucket where the battery charge is indicated by the amount of water in the bucket.
Now imagine that you are trying to fill that bucket as fast as possible, which means using a firehose, and that spilling any water means damaging the bucket.
Getting the bucket close to full without making a mess is a lot easier than getting it 100% full which means you need to slow the fill down to trickle to make sure you don't over flow or splash water everywhere.
Charging the last 10% of battery capacity is difficult because the battery does not readily accept a charge as it's nearly full. This means to get the last 10% of capacity you need to slow down the charge rate, which means that in this case, it may only take 10 minutes to get to 90% full, but it may take another 30-60 minutes to charge up that last 10% without damaging the battery.
Are you implying that the this story is a dupe? It's not really, when you read TFA's. The article from the previous slashdot story is from before Toshiba has released anything. Now the battery is out (for industrial applications), and the most recent slashdot article refers to Toshiba's laptop battery prototype.
Comparing to the number of cycles for a lithium ion battery doesn't make sense as lion batteries don't primarily degrade from cycling. Unlike some other battery technology, there is a major difference between the battery life when you cycle a lithium ion battery 100 times repetitively, and cycle it 100 times keeping it at 100% for a month between cycles. While the first would have degraded some, the latter could have degraded enough to be mostly dead.
It's almost a given that any details about some new battery technology always avoids the negatives. Those hopeful or shilling simply avoid the bad stuff. other li ion batteries can be recharged quickly and either 1) cost a fortune and weigh a ton (Altair) or 2) diminish their lifespan by so doing. Regardless, it all comes down to cost.This article says nothing about practicality, weight, etc.
That would depend some on the application, if a 90% charge in your battery bank in a electric car will get you 50 miles, then "50 miles charge in 10 minutes" would sell just fine. But if they also want to be able to boast about the total battery life and charge capacity, they can't be under rating them "This flashlight charges in to full in 15 mins and can be recharged 5000 times". If the charge rate drops significantly for the last 10% of charge, then it would behoove engineers making products that use these batteries to design around a 90% ten minute charge.
How about, "This flashlight charges to full in 10 minutes. If you leave it plugged in for another two hours, you get an extra 10% 'superboost' charge!"
This is marketing language we're talking about, after all.
Probably because then you would then ultimately charge the battery to 111% of its rated capacity, which would make people frightened.
Also, when measuring charge/discharge cycles, the rated capacity would be used, not the 111% rated capacity. I think that being straightforward is better, so I have very little problem with Toshiba's description.
oh i dunno, maybe honesty has something to do with it? not everyone is obsessed with advertising/marketing double-speak.
besides, why intentionally take 10% off of your advertised battery capacity? i think most consumers would be able to do the math and see that the competitor's 10 min. 90% charge is exactly the same as your 10 min. 100% charge--except the competitor's battery has 111% the capacity of your battery. that could be an extra 2 hrs. of music or games.
on a somewhat related note, a came across an interesting article while researching Li-ion batteries on wikipedia. apparently some Li-ion batteries [businesswire.com] are capable of being _fully_ charged in 10 minutes. so maybe this isn't as big of a breakthrough as it initially seemed?
The reason 90% is a target for batteries has to do with the input energy required to achive the charge. The higher the existing charge, the more resistance created trying to increase it further. Some of you math nuts out there can help me out and give me the exact equasion, which I have not had enough coffee yet to recall, but there is a scientific reason why we do not simply charge directly to 100%.
1st, charging to 100% vs 90% takes more than 10% more energy. Quite a bit more actually, and is wasteful.
but W and the neo-cons KILLED the majority of our long term research and throw most of it towards coming up with hi-tech close term solutions for the DOD. In essence, they shutdown a lot of long-term multi-discipline research in our universities and various companies like GE, IBM, Lucent, etc and channeled it into a number of companies (GM, L-MART, Rathyeon, Halliburton, etc).
First, that's 500 *full* cycles. Most people don't completely drain Lithium Ion batteries before recharging them.
Second, that's not 500 cycles until the battery dies, it's 500 cycles before the battery only holds a certain percentage — usually 80% — of it's initial charge.
What also kills Lithium Ion batteries is internal oxidation, which occurs whether the battery is cycled or not. Storing a battery at 100% charge actually causes the battery to lose life as much as five times faster than if the battery was at 50% charge. In other words, if your devices spend most of their time at less than full charge, your batteries will last longer than if you let them sit on the charger for years on end.
Speaking of which, I wish all notebooks, MP3 players, and other gadgets gave you the ability to set a charging limit. I've only seen the feature on some Sony notebooks (they call it a "battery care" utility). If you could limit your devices to, say, a 40% charge when they're just going to be sitting around the house all day, and only charge them up to full when you really need the battery life, you'd probably never need to replace a Lithium Ion battery again.
a better link (Score:5, Informative)
Is the InfoWorld article this seems to have come from:
Right here [infoworld.com]
This is being shown in a laptop, and will be in a Schwinn bicycle next year.
This sounds good, certainly, but I'm *really* hoping eeStor's superduperultracapacitor technology works out as advertised. That will change the world.
Re:a better link (Score:5, Informative)
Even better, this article [marketwatch.com]. More tech specs.
Parent
Re:Of interest... (Score:5, Informative)
Let's use Australian numbers (because I know them):
Available voltage from a standard wall outlet: 240v
Available amps: 10
Using Ohms law (and assuming resistance will remain roughly the same), I should be able to get nearly 100A @ 24v using a step-down transformer. Most laptops have an input of around 19v. As long as the leads can handle the amperage, it shouldn't be an issue.
It's the leads that will be an issue. IIRC, cars need 50-80A @ 12v to start. The leads that come off the battery for the starter motor are pretty big, and they only need to handle that current draw for up to 10 seconds...
Parent
Re:Of interest... (Score:5, Informative)
Actually it's quite a bit more than that in a car. You'll see a good 3-500 amps and more depending on engine size, age, temperature and other starting conditions.
In fact, batteries are rated in cold-cranking-amps - i.e. the number of amps they can supply to start the car while cold (probably around freezing, not sure of the exact temp measured at). A hefty battery is rated somewhere around 8-900 CCA.
You're right though - the wiring only needs to support that load for ~10 seconds in a worst-case situation so the conductors don't have to be as heavy as they would otherwise.
Parent
Re: (Score:3, Interesting)
Re:Of interest... (Score:5, Informative)
Parent
Re:a better link (Score:5, Informative)
This is basically the same technology AltairNano uses -- a traditional LiCoO2 cathode and a nanotitanate cathode replacing the traditional graphite one. In large format, you get 70-80Wh/kg. It's a little better than NiMH in that regard, but not much. It's also a lot more expensive (AltairNano's are $2/Wh; hopefully a heavy hitter like Toshiba can bring prices down). Where the chemistry shines is everything else. It's incredibly stable, rapid charges, handles a very wide range of operating temperatures, has a ridiculously high power density (~5 kW/kg), fire resistant, highly efficient, and so on down the line.
It's one of a variety of relatively new, commercially available li-ion chemistries, each with their own strengths and weaknesses. When you hear of lithium ion battery packs in electric vehicles, with the exception of Tesla, they're usually these new chemistries, not traditional LiCoO2/graphite cells. The next-gen chemistries look even more impressive, but we'll have to wait for them ;)
Parent
Re:a better link (Score:4, Interesting)
Looks great for "micro-hybrid" cars that use only a small battery for recovering braking energy and a boost on accelerating. In these applications, you need a lot of power density. Or simply as a starter battery (good bye lead-acid).
For plug-in hybrids or electric only cars, LiPO4 is also interesting:
somewhat higher energy density, and the lower power density is not a problem due to the larger battery. An example of a system that seems to be commercially available:
http://www.valence.com/products/epoch_overview.html [valence.com]
Parent
Re:a better link (Score:5, Interesting)
only 500 cycles, really? that seems a little low. do they mean that after 500 charges the battery begins to decrease in capacity, or that the battery will start to fail completely after 500 charges? because that seems really really low to me.
i mean, most rechargeable batteries today are Li-ion batteries, right? i just wanna know how many recharges i have left on my PSP.
does it help if you make sure to plug the battery back into the charger before it's out of charge? what can you do or not do to help preserve the capacity and life-span of a li-ion battery?
Parent
Re: (Score:3, Interesting)
I think it's pretty close - at a rough educated guess, I'd say that after 500 cycles without disciplined use (see below), you'll be around 30% of factory capacity. (I'm assuming a cycle every 1.5 days)
Supposedly keeping the battery between 30% to 70% charge is helpful; there are utilities for this for laptops, don't know about PSP. Running it all the way down is very bad, and when I got lazy about it, my battery life did plummet (though it may have just "aged" independently, it seems connected).
High tempera
Re:a better link (Score:4, Interesting)
hrm... well i guess it's a good thing that i've only let my battery die once or twice since i got it. with replacement batteries costing $40~50 a piece, i'll have to be more attentive about my charge state.
i seem to remember seeing several different stories on /. about "revolutionary" new battery techs, but i still haven't seen any alternatives to traditional li-ion batteries being sold at commercial retailers. IMHO lithium-titanate [wikipedia.org] batteries look promising. manufacturers are claiming that these new lithium batteries can recharge in under 10 minutes--and that's for use in electric vehicles. this New Scientist article [newscientist.com] reports that mobile devices using lithium-titanate can recharge in 6 minutes, and each battery is capable of going through 20,000 charge cycles.
i'm guessing this technology is probably still too expensive to bring to market. it'll probably only be used in electric vehicles or other such applications which require much more durability and longer life-spans than traditional Li-ion batteries currently provide.
Parent
Re: (Score:3, Interesting)
Those are 500 FULL cycles. Use 33% of the battery one day, recharge, 33% of the battery the next day, recharge, and 33% of the battery the next day, and recharge, and you'll bascially have used one full cycle.
Re: (Score:3, Interesting)
>>>Use 33% of the battery one day, recharge, 33% of the battery the next day, recharge, and 33% of the battery the next day, and recharge, and you'll bascially have used one full cycle.
Nope. You see, batteries are a lot like dogs. If you overfeed your dog, he won't live long. If you underfeed you dog, that too can shorten his life. If you alternate between stuffing your dog full of food, and then not feeding him for a whole week until he's skin 7b ones, that too can damage him due to the stress
Re: (Score:3, Informative)
The benefit of Li-Tit (SCiB) is not density, it's charge time. Li-Tit batteries reach 80+% charge in 90 seconds. Yes, some other batteries hold more charge per volume or charge per weight, but Li-Tit batteries have a MAJOR advantage in automobile use where volume is not as much of an issue as charge time.
The Li-TiT (SCiB) batteries first of all are old news, and I don;t know why this is on /. now. It;s not only old news as far as science, it's old news as in they've been sold on the open market in large
Re: (Score:3, Interesting)
Supposedly keeping the battery between 30% to 70% charge is helpful; there are utilities for this for laptops, don't know about PSP.
Somewhat offtopic, but I've been wondering about this: my main laptop is currently also my main desktop. As such, while I run it off the battery every now and then, it's plugged in most of the time. Does this have a negative effect on the battery life? Should I use the battery more often?
Re: (Score:3, Interesting)
It's definitely not ideal. If you keep it in your laptop, it's going to be much warmer than room temperature (because the laptop is warm) and fully charged.
Basically that's really bad storage. See here:
Wikipedia on Li-ion battery life [wikipedia.org]
To summarize the above page, it's best to store a battery a bit less than half-charged, and not above room temperature. So to preserve your battery when you really need it, take it out.
Re:a better link (Score:5, Informative)
only 500 cycles, really? that seems a little low. do they mean that after 500 charges the battery begins to decrease in capacity, or that the battery will start to fail completely after 500 charges? because that seems really really low to me.
i mean, most rechargeable batteries today are Li-ion batteries, right? i just wanna know how many recharges i have left on my PSP.
does it help if you make sure to plug the battery back into the charger before it's out of charge? what can you do or not do to help preserve the capacity and life-span of a li-ion battery?
Li-ion batteries are usually limited by 'calendar' life, not charge cycles - they start losing capacity the moment they are packaged at the factory and generally last a couple of years before they become too weak to use.
However, there are some strategies to extend their life:
1. Keep them cool (but not frozen)
2. Keep them at around 40% charge
Now, this probably isn't too useful for batteries that you are actively using - however, if you have spare lithium batteries lying around that you aren't using at the moment you might want to drain the charge to about 40% and zip them up in ziplock bags and put them in the fridge until you need to use them (check it once in a while to make sure they haven't drained to zero charge because that can kill them).
Also, this means that you should avoid letting your Li-ion batteries get hot unnecessarily, like leaving them in a hot car in the summer.
This is a good reference http://www.batteryuniversity.com/parttwo-34.htm [batteryuniversity.com]
Parent
Re:a better link (Score:5, Funny)
Parent
Re: (Score:3, Insightful)
Re: (Score:3, Interesting)
I'm increasingly sceptical of EEStor. They've just signed another "worldwide exclusive" deal with a tiny company called LightEVs for all 2 and 3 wheel vehicles. The deal they did previously with Zenn covers all small to midsized cars so they've now conceeded a big chunk of their margin to a couple of nobodies. You've got to wonder - how are these companies adding value? What's their track record? Why hasn't EEStor made deals with more established manufacturers? A single working prototype which has the perfo
Oh Cool! (Score:5, Funny)
Will this battery explode or just burst into flames?
Re:Oh Cool! (Score:5, Funny)
Depends on how charged it is... less than 90% it bursts into flames, greater than 90% it explodes.
Parent
Re: (Score:3, Interesting)
Sounds like LiFePo4 (Score:5, Informative)
Well, the stats itself sound pretty much like A123 or similar cells: Lithium with an ironphosphate instead of cobalt anode material.
They have higher cycle times, and they can be charged at up to 5C without much problems (which would agree with the 10 min stated).
But they have a drawback: Only about half the energy density compared to normal Lithium Ions.
Not to mention that in order to really charge them that fast, you will need a much higher rated, and thus bigger/heavier PSU brick for the notebook...
Re: (Score:3, Insightful)
But they have a drawback: Only about half the energy density compared to normal Lithium Ions. Not to mention that in order to really charge them that fast, you will need a much higher rated, and thus bigger/heavier PSU brick for the notebook...
On the other hand, this is only (to become) the first commercial version of this battery. Give it a few years and we might be seeing promising things.
Having said that, I don't think this product is directly targeting the laptop industry. For starters, as you mentioned, it requires more space. Secondly, when and if it gets commercially available for laptops, we'll be seeing fuel cell batteries as well. They offer more performance and that instant recharge factor as well.
I think this is an excellent pro
Re: (Score:3, Funny)
So you are saying that this may charge 90% in 10 minutes, but in my new quad core dual SLI 20" laptop it will be fully discharged in 10 minutes?
Why 90% (Score:4, Interesting)
Or are they charging while running - and perhaps not able to get all the way to 100%? The article was lousy (to be generous) and doesn't say what it would take to reach 100%.
Re:Why 90% (Score:5, Informative)
Yes, there is:
Typically, the last few % take a as long as everything before together. Its just that the nature of the chemical reactions involved: During the charge, the battery voltage increases. The charger OTOH cannot push more than 4.2V (for normal batteries) respectively 3.7V for LiFePo4, in order not to damage the cells. This means that effective voltage drops during the charge, and duringe the last bits of capacity, there are only some 0.1V left. Add internal resistance, and its clear why it cannot fill up completely fast
Other comments suggested downrating, but that doesnt really make sense: as long as you leave it in the charger, it will gain charge for a while, so the real capacity is truely higher.
Parent
Re:Why 90% (Score:5, Funny)
Parent
Re:Why 90% (Score:5, Funny)
I just spat Newcastle all over my keyboard reading this post. Luckily it still appears to be work
Keyboard, shmeboard...won't somebody think of the Newcastle!?! Let's all have a moment of silence for a nice brown ale gone to waste.
Parent
Re:Why 90% (Score:5, Interesting)
If you think of a battery as a bucket where the battery charge is indicated by the amount of water in the bucket.
Now imagine that you are trying to fill that bucket as fast as possible, which means using a firehose, and that spilling any water means damaging the bucket.
Getting the bucket close to full without making a mess is a lot easier than getting it 100% full which means you need to slow the fill down to trickle to make sure you don't over flow or splash water everywhere.
Charging the last 10% of battery capacity is difficult because the battery does not readily accept a charge as it's nearly full. This means to get the last 10% of capacity you need to slow down the charge rate, which means that in this case, it may only take 10 minutes to get to 90% full, but it may take another 30-60 minutes to charge up that last 10% without damaging the battery.
Parent
Previously on Slashdot: (Score:4, Informative)
http://hardware.slashdot.org/hardware/07/12/13/1714258.shtml [slashdot.org]
Re: (Score:3, Insightful)
Are you implying that the this story is a dupe? It's not really, when you read TFA's. The article from the previous slashdot story is from before Toshiba has released anything. Now the battery is out (for industrial applications), and the most recent slashdot article refers to Toshiba's laptop battery prototype.
Bullshit Meter (Score:5, Funny)
Story about battery tech + 7 ... compared to standard ..." + 4
InfoWorld + 5
"prototype" + 10
" in just " + 15
"Super" + 3
A new acronym + 6
"capable of
Total - 50.
It stinks, but who knows - it may just be a fine cheese or chocolate.
On the other hand, the Vaporware Meter is off the charts, and the "durable material" and it's claims broke the poor Economic Feasibility Meter.
Re:Bullshit Meter (Score:5, Informative)
These batteries are already available, for example see:
http://www.toshiba.co.jp/about/press/2008_09/pr2401.htm [toshiba.co.jp]
This is a prototype of a *laptop version* of the battery.
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Cycling of lithium ion batteries? (Score:4, Informative)
In other news (Score:3, Funny)
so whats new ? (Score:4, Informative)
A123 LiFePO4 batteries have been charged [horizonhobby.com] at 10-15 minute rates by RC crowd for a couple years by now.
More importantly, (Score:4, Insightful)
How long does it take to discharge?
More details - this tells me nothing (Score:3, Insightful)
Re:90% = Bad Marketing? (Score:4, Informative)
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Re:90% = Bad Marketing? (Score:5, Funny)
How about, "This flashlight charges to full in 10 minutes. If you leave it plugged in for another two hours, you get an extra 10% 'superboost' charge!"
This is marketing language we're talking about, after all.
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Re:90% = Bad Marketing? (Score:4, Funny)
The signature is a forgery.
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Re: (Score:3, Interesting)
Probably because then you would then ultimately charge the battery to 111% of its rated capacity, which would make people frightened.
Also, when measuring charge/discharge cycles, the rated capacity would be used, not the 111% rated capacity. I think that being straightforward is better, so I have very little problem with Toshiba's description.
Yeah, but then your battery really could go to 11 (Score:5, Funny)
How could any geek not want a battery like that?
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It doesn't blow up though! (Score:3, Funny)
What use is a new technology if it can't explode..
bad geek!
bad geek!
*slap*
Re:90% = Bad Marketing? (Score:4, Interesting)
oh i dunno, maybe honesty has something to do with it? not everyone is obsessed with advertising/marketing double-speak.
besides, why intentionally take 10% off of your advertised battery capacity? i think most consumers would be able to do the math and see that the competitor's 10 min. 90% charge is exactly the same as your 10 min. 100% charge--except the competitor's battery has 111% the capacity of your battery. that could be an extra 2 hrs. of music or games.
on a somewhat related note, a came across an interesting article while researching Li-ion batteries on wikipedia. apparently some Li-ion batteries [businesswire.com] are capable of being _fully_ charged in 10 minutes. so maybe this isn't as big of a breakthrough as it initially seemed?
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Re: (Score:3, Interesting)
The reason 90% is a target for batteries has to do with the input energy required to achive the charge. The higher the existing charge, the more resistance created trying to increase it further. Some of you math nuts out there can help me out and give me the exact equasion, which I have not had enough coffee yet to recall, but there is a scientific reason why we do not simply charge directly to 100%.
1st, charging to 100% vs 90% takes more than 10% more energy. Quite a bit more actually, and is wasteful.
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We do (Score:3, Interesting)
Re:Only 500 cycles? (Score:5, Informative)
First, that's 500 *full* cycles. Most people don't completely drain Lithium Ion batteries before recharging them.
Second, that's not 500 cycles until the battery dies, it's 500 cycles before the battery only holds a certain percentage — usually 80% — of it's initial charge.
What also kills Lithium Ion batteries is internal oxidation, which occurs whether the battery is cycled or not. Storing a battery at 100% charge actually causes the battery to lose life as much as five times faster than if the battery was at 50% charge. In other words, if your devices spend most of their time at less than full charge, your batteries will last longer than if you let them sit on the charger for years on end.
Speaking of which, I wish all notebooks, MP3 players, and other gadgets gave you the ability to set a charging limit. I've only seen the feature on some Sony notebooks (they call it a "battery care" utility). If you could limit your devices to, say, a 40% charge when they're just going to be sitting around the house all day, and only charge them up to full when you really need the battery life, you'd probably never need to replace a Lithium Ion battery again.
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