Amiga.org
Coffee House => Coffee House Boards => CH / Science and Technology => Topic started by: motorollin on May 07, 2008, 06:02:25 PM
-
Link (http://www.newertech.com/products/charger_cond.php)
Apparently this device not only charges batteries but also reconditions them. The manufacturers even claim it will "bring back additional life to a battery that's started to show its age". Anyone know if this is really possible? I've got a MacBook battery which now only lasts 1 to 1.5 hours on a full charge compared to 4 hours when I first got the machine. Could this machine really "repair" the battery?!
--
moto
-
I've heard that putting the battery in the freezer will also do some good to batteries.
-
Hmm, Googled that and found this (http://www.batteryuniversity.com/parttwo-34.htm):
There are no remedies to restore lithium-ion once worn out. A momentary improvement in performance is noticeable when heating up the battery. This lowers the internal resistance momentarily but the condition reverts back to its former state when the temperature drops. Cold temperature will increase the internal resistance.
Also:
Do not freeze the battery
Sorry, no prize this time Speel :-)
--
moto
-
motorollin wrote:
Sorry, no prize this time Speel :-)
--
moto
Hm I didn't have a lithium-ion I think.
Tis an old laptop I tried it with, in my case I had no succes, it made no difference.
-
This battery is behaving very strangely. The machine often powers off when there is supposedly some charge left, and the machine won't power on again until the power is connected. Other times it will run right down to 0%. Tonight I'm trying to run it down to 0% so I can fully charge it up to 100% again. However, every time I let the machine power off, when I plug the power cable in and boot it up again then remove the power cable, I have another 10 minutes or so of battery life :-?
Is it safe to keep doing this until the battery is *really* empty, or will that fsck the battery up?
--
moto
-
AFAIK it's SUPPOSED to become completely empty, and the very reason laptop batteries often get bad is because of recharging when not empty.
-
Hmm so I guess that device I linked to above forces the battery to totally discharge before charging it? I wonder if there is a way to make the computer do this, maybe a boot disc which will run the battery right down.
--
moto
-
Could be, but personally I always prefer hardware doing these kinds of jobs.
-
Ok, thanks!
--
moto
-
Li-ion batteries have a very limited life span. No more than 1.5 years really, and probably not more than around 150 to 200 charge cycles before capacity degridation sets in.
Once the battery starts to lose capacity there is no way to restore it, the battery has physically degraded.
Try to avoid deep cycles with lithium batteries they work best when kept nearly full at all times.
-
bloodline wrote:
Li-ion batteries have a very limited life span. No more than 1.5 years really, and probably not more than around 150 to 200 charge cycles before capacity degridation sets in.
Once the battery starts to lose capacity there is no way to restore it, the battery has physically degraded.
Try to avoid deep cycles with lithium batteries they work best when kept nearly full at all times.
ditto. That's my understanding too.
I believe heat will also degrade a Li ion battery. Don't heat them, and don't leave them in a car, direct sunlight, etc.
motorollin wrote:
This battery is behaving very strangely...
Battery management ICs generally use an analogue sense circuit to judge the battery's state. The sensory elements are often not very precise, and may not really indicate the true state of the battery. I worked on a battery management design a while back, and all the ICs required individual external trimming, and most would not perform reliably on batteries of all different conditions. Unfortunately, cheap analogue IC elements are subject to this kind of variation.
-
bloodline wrote:
Li-ion batteries have a very limited life span. No more than 1.5 years really, and probably not more than around 150 to 200 charge cycles before capacity degridation sets in.
Hmm, my MacBook battery is 2 years old and has had way more than 200 charge cycles...
bloodline wrote:
Once the battery starts to lose capacity there is no way to restore it, the battery has physically degraded.
What if I put in some more lithium? ;-)
bloodline wrote:
Try to avoid deep cycles with lithium batteries they work best when kept nearly full at all times.
That's what I was told about iPod batteries, yet all three of mine refused to keep their charge. The first one (bought brand new) stopped holding charge after a few weeks. Replaced by Virgin, and the next one lasted just under a year. After much arguing with Apple they replaced it, and that one lasted 3 months. Apple refused outright to replace it. After that I vowed never to buy another Apple product which didn't have a removable battery, but then the iPhone came along... :roll:
--
moto
-
Oliver wrote:
Battery management ICs generally use an analogue sense circuit to judge the battery's state. The sensory elements are often not very precise, and may not really indicate the true state of the battery. I worked on a battery management design a while back, and all the ICs required individual external trimming, and most would not perform reliably on batteries of all different conditions. Unfortunately, cheap analogue IC elements are subject to this kind of variation.
Are you saying that the battery might not actually be as bad as the computer thinks? Or that it's not actually fully charging it? Or both? Or neither? :-)
--
moto
-
motorollin wrote:
Oliver wrote:
Battery management ICs generally use an analogue sense circuit to judge the battery's state. The sensory elements are often not very precise, and may not really indicate the true state of the battery. I worked on a battery management design a while back, and all the ICs required individual external trimming, and most would not perform reliably on batteries of all different conditions. Unfortunately, cheap analogue IC elements are subject to this kind of variation.
Are you saying that the battery might not actually be as bad as the computer thinks? Or that it's not actually fully charging it? Or both? Or neither? :-)
--
moto
More often than not I guess... analog to digital (or vice versa) is very fragile stuff.
-
Apple refused outright to replace it. After that I vowed never to buy another Apple product which didn't have a removable battery, but then the iPhone came along... :roll:
Eh? The IPhone's battery can't be replaced?!
-
odin wrote:
Eh? The IPhone's battery can't be replaced?!
Nope. Not officially anyway. Like the iPod, the battery is sealed inside the housing. The only way to get it out is to use specialist tools to get the case open.
--
moto
-
motorollin wrote:
Are you saying that the battery might not actually be as bad as the computer thinks? Or that it's not actually fully charging it? Or both? Or neither? :-)
--
moto
The battery management IC may not be reporting an accurate assessment of the battery's state to the computer. The OS may then not indicate the accurate state to you, and may not make the appropriate power management decision at the appropriate time.
That is the most general way I can decribe it, without going into specific scenarios. Hope it makes sense.
Oliver
-
That makes perfect sense - thanks :-)
--
moto
-
fwiw, it's not all LiIon batteries that have a limited life from the date of manufacture - it's specific kinds of LiIons, and newer ones seem a bit more fragile than older ones.
Posting from a G3 powerbook that last night ticked a bit over six hours web/irc/writing/wireless 'net use on a pair of batteries - one built in 1998, the other in 2001 - both LiIon (I have another spare here somewhere that still gets about 2 hours, too)
Dana
-
the controller ics for lithium ion batteries have to deduce charge from last charge time and length and amount of usage. some use temp also. this is because lithiums output voltage varies so little from full charge to no charge.
lead acid are pretty easy, 13.5 or so is full less than 11 or so is empty and go to low and yiu can fry them unless they are deep charge.
the degrade of lithium storage with age is unpredictable, or is only if you can keep track of charge history, temperature and usage over the entire history of the individual cells- kindoff tough. the tesla lithium ion powered car has an individual cpu for each of its thousands of cells.
nicad batteries build stalagtites of electrolyte meterial between the poles with use that eventually short the cell out. they can be burned off with a couple microseconds of high (110v or so) zap. that returns power to original for a short time but they usually grow back quickly.
-
motorollin wrote:
What if I put in some more lithium? ;-)
I think you'll find these are your weak link:
(http://www.germes-online.com/direct/dbimage/50279947/Electric_Iron.jpg)
:-D