Can you overcharge a laptop?

Question

My friend says it shouldn't be plugged in for too long once it has been shut down.

Answer 1

There are a lot of myths surrounding batteries, and to make matters worse, a lot of different battery types. I suggest reading this page:

http://www.batteryuniversity.com/

In general, notebook chargers stop charging once the battery is fully loaded (only a 'trickle charge' remains) and this does not damage the notebook in any way.

Answer 2

Ya, this is what my friend do too. Look for the signal when its fully charge, discharge the battery.

My schoolmates is using a notebook every now and then, or another word is everyday. In fact, it's compulsory.

Normally notebook battery life lasts 2 years from the day you bought your new battery. From many websites, it says that laptop battery need to change every 2 years.

My friends, in fact 70% of my friend normally charge their battery at school during lesson time while they are using the laptop, after the battery is full, they would remove the battery and let the laptop run by the AC power.

To me, it might be a bit foolish but whether it's a myth or truth, althought is seems to be troublesome to lookout for the signal, but it may or may not benefit the battery and it won't take away something from you if you go the extra mile. BUT, I choose to believe, so I also do the same way as my friends do :D

Answer 3

There are some suggestions provided by a After-sales service staff of SONY corporation.

Laptop battery maintenance


1. In the use of notebook computers read carefully before using manual battery maintenance;


2. First charge, you should continuously recharging the battery to 12 hours, and completely filling cycle, the discharge three times to completely awaken new battery;


3. If prolonged use external power supplies, the best remove the battery. Many of my friends not aware of this issue, when using an external power supply not only remove the battery does not affect battery life, but also the heat for laptops become even heavier burden, shortening the life span of notebook computers;


4. Regular charge and discharge. Even without the memory effect of lithium-ion batteries There is a certain inertia effect, a long time not to use lithium-ion lost activity will need to re-activate. Therefore, if a long time (three weeks or longer) that do not use computers or battery charge and discharge time shorter, should enable the battery fully discharged before recharging, generally at least a month to complete charge-discharge 1.


5. Charging switch off the best laptop, the battery can be completely filled with electricity, not to unplug the power in the middle of charge. Shutdown boot charging rechargeable than shortening more than 30 percent of the charge time, but can extend battery life.


6. Prevent exposure to prevent damp to prevent erosion chemical liquids, avoid contact with the metal of the battery contacts in case of short circuit occurred.


Lithium battery charge and discharge frequency is generally not more than 800 times - once for each charge, it would shorten the life span of time. Propose that we make full use of external power, if used repeatedly inserted halfway power needs, and built-in laptop computer battery did not pull out, will make the lifespan of battery shorter, because every time access to external power equivalent to a battery charge

Answer 4

The battery will only accept a charge until it is fully charged.
The best way to maintain battery life is to completely discharge the battery now and again and let it trickle charge (charging while you are using your computer connected to the power supply). This prolongs the battery life and makes it work better (something I read somewhere but have no proof that it actually works or is beneficial in any way).

Answer 5

to answer you to the point,
the 'charge monitoring and charging circuit' in you laptop operates on the dc voltage from the power adapter
hence it does not matter if your laptop is running or shut down

if batteries are fully charged, no charge is allowed into batteries

in short, your friend is mis-informed

EDIT:
straying from the point, i also would advice against deep discharge > as suggested in one answer
this was in vogue when ni-mh batteries were used, NOT present day li-ion

Answer 6

No. WHen the batterys is full the charger will turn off the charging but still power the laptop.

GL

Answer 7

The battery will only accept a charge until it is fully charged