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tefaz

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Why is my Laptop Battery stuck at 29% ?

Hi, my laptop (XPS 1530) battery is stuck at 29%, its not charging beyond that. The status of the battery is ("Plugged in, not charging") :S .....

why is that ?!!! will i have to buy a new one ?!! or is it a Bios problem ?!!! note that 29% stays 50 min (its working probably) .....

I hope to hear good news other than buying a new one :) .....
Thanks in Advance .....
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Callandor
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Try draining it down to almost zero and then recharge it fully.  Your battery may be suffering from "memory effect".
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JohnBPrice

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tefaz

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@Callandor : i tried ur suggestion, unfortunately it didn't work ... my battery now is stuck at 24% .... i think "JohnBPrice" is right cuz i take my laptop to the university everyday and leave it in the car if i don't need it + it has an overheating problem :( ... so i think i really need to buy a new one as the warranty is expired from one month ONLY :S ...

Thanks for ur help ^^ ....
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if anyone have a theory and would like to try it, i don't mind :D since i will replace it anyway ...
Everything you wanted to know about Lithium batteries.  

http://www.batteryuniversity.com/parttwo-34.htm

In short, don't freeze them, don't let them get hot.  Don't drain them completely.  Don't keep them fully charged.  Don't cycle them except rarely.

Note the chart that at 25F/77F a battery will have 80%-96% of its capacity after one year, at 40C/104F, it will be 65% to 85% after one year and at 60C/140F (car sitting in sun) it can be as low as 60% after only 3 months.
"if anyone have a theory and would like to try it"

Well, secretly I always did want to know if they will REALLY catch fire if you open them....
Well, since it can be toast already, you can try finding the battery terminals proper and completely discharge it using a lightbulb or a resistor. Then put it back in the computer and try to recharge it. If you're lucky, the metering circuitry will reset and re-sync with the battery. I tried it once and it worked; the metering circuitry sometimes just seem to get out of whack and fail to register correct battery capacity.

If your BIOS has a battery calibrate option, try that.

/RID
"completely discharge it using a lightbulb or a resistor"

Lithium Ion batteries should never be completely discharged in this way.   Completely discharging them will cause the recharge circuitry to no longer attempt to charge the battery and it will damage the battery further.  It is also very dangerous.
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ASKER

"Completely discharge it using a lightbulb or a resistor"

"Completely discharging them will cause the recharge circuitry to no longer attempt to charge"

wow, i was just going to discharge it completely :S ....
can someone confirm please ?!! discharge or NOT ?!!

NOTE: I dont wana lose the battery now before buying a new one ...
Read the article at the link I sent you, or the abbreviated wikipedia version at http://en.wikipedia.org/wiki/Lithium_ion
Well, since the battery is verging on useless anyway, you wouldn't lose much if the thing went dead. As for dangerous, well, possibly. Depends on the discharge current. A short-circuit is always dangerous, discharge with a smallish lightbulb, probably not. The problem is if one or more of the cells go "in reverse", but that should be indicated by the output voltage. If the nominal voltage is say 12 V and the voltage during discharge is 8 or something like that, you have a reversed cell and that is potentially hazardous. Put a screen in front of the experiment and don't leave it unattended for long.

I'm also not convinced that a flat battery will not charge. Such batteries can go flat from time alone and I'd expect them to re-charge anyway unless they're damaged internally. Possibly it's a feature built into the controlling circuits, to make you buy new batteries more often.
/RID
"battery is verging on useless anyway"

True.  

One might pick up a new battery, then have fun with the old one.  In addition to a screen, I'd do it outdoors (and wear safety glasses).  Maybe do some research on safe discharge rate , measure the voltage, and pickup a resistor at Radio Shack to get below the safe discharge rate.  A flashlight light bulb for say 3V will not do because the cells are in series to get about 11V (at least on my Dell Latitudes) you will blow the bulb or get a too high discharge rate.  If you get too high a discharge rate, the batteries will self-destruct, there is a device in them that will permanently disable them to prevent them from exploding.  Don't use an LED, they have very little resistance.  Note the battery pack itself  will stop the discharge at about 3V per cell (this is NOT the 11V voltage you see at the battery pack terminals).

I AM NOT RECOMMENDING OPENING THE BATTERY PACK. IT IS DANGEROUS.  DON'T SUE ME.
 
"I'm also not convinced that a flat battery will not charge"

Perhaps.  I've read it and I have had that experience with one Dell battery.  It was uncharged and unused for a while, and now will not charge at all.  The computer refuses to try and says the battery is not functional (or something like that)