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Lately me laptop battery is charging for less than an hour at less than 10% charge. When it should be more than 3 hours to charge. How do I calibrate my laptop battery so that it goes to normal again. This laptop is less than 1 yr old.

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Read the comments below, but also since the laptop is less than one year old, you should check into having your battery replaced by the warranty. –  KCotreau Jul 10 '11 at 12:17
    
@KCotreau Batteries are typically excluded from warranties, as they are considered to be worn by use rather than having a manufacturing defect. Local laws may force a manufacturer to replace them anyway, but that is not a universal truth. –  Asterix Jul 10 '11 at 17:03
    
@Asterix That is not correct. They may have a lesser warranty, but almost every manufacturer covers their batteries for at least a year. Dell 1-year: dell.com/content/topics/global.aspx/batteries_sitelet/en/… HP 1-year: welcome.hp.com/country/us/en/privacy/limited_warranty.html Lenovo As long as your extended warranty lasts: lenovo.com/services_warranty/us/en/… Do I need to go on? –  KCotreau Jul 10 '11 at 17:16
    
@KCotreau Regional differences, I think. In Italy, some manufacturers (e.g., Asus, I did not do a brand-by-brand check) cover batteries for only six months. Interestingly enough, Dell does cover a full year of warranty even in Italy, and even offers an extended warranty specifically for the battery, but it only covers one replacement. –  Asterix Jul 11 '11 at 16:31
    
@Asterix Valid point about the regions. You pointed out something I often mention, but this time, I did not consider it. I would hope that major manufacturers would maintain their policies from country to country, but clearly they do not have to. Still, to say they are "Typically excluded" is still not really correct either. –  KCotreau Jul 11 '11 at 16:39
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2 Answers

up vote 6 down vote accepted

Modern lithium batteries are typically "smart": they have an internal controller that tracks recharge history and detects any "lost" capacity, to prevent dangerous overcharges. If they didn't, your laptop would occasionally catch on fire. You probably don't want that.

Unfortunately, sometimes the controller detects lost capacity... A little too well, so to speak.

Now, before you put your battery in the freezer, remember that chips are often more susceptible than the battery itself to low temperatures, so the usual freezing trick (which has about an even chance of working on dead NiMH batteries) is not a good idea: it may result in a broken controller, which may be a literal health hazard (see above about laptops catching on fire).

A full discharge, followed by a full charge in a very cool and well-ventilated place (you need a cool battery to improve the results, but you don't want any humidity to condense on your laptop's innards), may cause the controller to reassess the status of your battery.

Don't go overboard with the cooling: stay above 0 (or, above 32, for USians).

Unfortunately, lost capacity is usually a one-way trip, so there is no guarantee that even a good recharge cycle will cause the controller to reevaluate your battery's health status. If you get no results at all after 5 to 10 cycles, either your battery is too damaged or its controller is not designed to detect improvements.

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What makes the battery reassess the status: a full discharge, or a full charge? And is it sufficient to put the charging laptop on top of a cooling pad, to provide the cool environment? –  landroni Mar 7 at 9:24
    
See also: superuser.com/questions/72000/… . –  landroni Mar 7 at 9:31
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The battery could have lost its ability to retain a charge. It not a calibration issue so much as its a "your battery is not that good anymore" issue.

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