Query regarding Laptop Battery Charging

KrazzyDJ

Junior Member
Sep 28, 2012
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Hi,

I was trying to figure this out over the internet but managed to find two contradicting viewpoints regarding this issue which is why I decided to clarify it here. Does it cause any harm to the battery if say the laptop charger is plugged in despite the battery being full ??? One opinion goes that this shortens the battery's life due to overcharging. Hence, you should let your laptop battery discharge to a low level (say till 20% of it is left) and then recharge it. The other opinion goes that when the laptop's battery is full and the laptop charger is plugged in, the laptop tends to use power available from the charger as the main power source instead of using the battery.

So which opinion is right ??? Or none are completely right and I've got it all wrong ??? Some help is appreciated.
 

corkyg

Elite Member | Peripherals
Super Moderator
Mar 4, 2000
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Surprised you only found two opinions. The answer depends on several factors. How the laptop is used. What kind of battery it has. The laptop's own charging and control system. This question recently came up in the Lenovo forum, and there are several valid responses supported by technical data.

http://forums.lenovo.com/t5/T400-T5...ging-battery-life-of-a-new-laptop/td-p/875211

My laptop is basically for travel. It is connected sans battery at home on a routine basis, and is frequently turned on to keep things up to date. The Li-Ion battery is removed and stored in a cool, dry place at about a 40-50% charge. It is only installed when prepping for a trip - about 3-4 times a year.
 
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cl-scott

ASUS Support
Jul 5, 2012
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On older laptops then yes, on any laptop made within probably the last 10 years, no.

Once laptop makers started using "intelligent" charging circuits, this largely became a non-issue. The long and short of it is that laptops now shut off the charging circuit when the battery hits 100%, and doesn't turn it back on until it gets down below about 95%. Which is kind of a balance between prolonging the service life of the battery and making sure that at any given moment you want to unplug the laptop from AC power, you have a "full" charge still.
 

KrazzyDJ

Junior Member
Sep 28, 2012
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0
So since my laptop is new (purchased about 4 months ago) I don't stand a chance of risking my battery life if I keep the charger on and plugged in even when the battery is full because this would shut down the charging circuit and avoid overcharging. That's how I've been using my laptop almost all the time - I plug in whenever I find an outlet.
 

MarkLuvsCS

Senior member
Jun 13, 2004
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So since my laptop is new (purchased about 4 months ago) I don't stand a chance of risking my battery life if I keep the charger on and plugged in even when the battery is full because this would shut down the charging circuit and avoid overcharging. That's how I've been using my laptop almost all the time - I plug in whenever I find an outlet.

Have all laptop manufactures implemented that yet? I know the T530 i have actually shuts off the battery LED light once it gets full and no longer says charging. I can see a lot of companies cutting out on the low end having it if nothing else to shave a buck off cost. I'm curious because I'm really not sure.