[Cyberianhusky]

Is it wise to leave a (fully charged) battery in a laptop while it is plugged into ac power plug. Will hurt or dimish the battery. Or is best use the ac plug and take the battery out while at home. I have a duo core chip.

[JohnWill]

The laptop charging circuit automatically limits the charge when the battery is fully charged, there should be no issue in leaving the battery in. Also, LiIon batteries don't like to be fully discharged, they're not like NiCad batteries, charge/discharge cycles are NOT good for lithium batteries.

[DoubleHelix]

Originally Posted by JohnWill

The laptop charging circuit automatically limits the charge when the battery is fully charged, there should be no issue in leaving the battery in. Also, LiIon batteries don't like to be fully discharged, they're not like NiCad batteries, charge/discharge cycles are NOT good for lithium batteries.

This is what I believed as well. However, I just read in Laptop magazine a few weeks ago that all laptop users should allow the batteries to discharge completely on a regular basis.

[johnpost]

it is good to exercise all rechargable batteries though not
to the point of zero, which could kill it.

nicads in order to treat well should be deeply discharged.

li-ion batteries don't do as well with frequent deep discharges
but still should be exercised. if it is kept charged and warm,
a case of a laptop run mostly on ac mains, it is bad for the
battery in terms of its lifetime. you should run the laptop
off battery power every so often to help out the battery.
bring up the battery monitor and let it discharge significantly.

[JohnWill]

The question is often asked, should the laptop be disconnected from the main when not in use? Under normal circumstances, it should not matter with lithium-ion. Once the battery is fully charged, no further charge is applied. However, there is always the concern is malfunction of the AC adapter, the laptop or the battery.

[johnpost]

Originally Posted by Cyberianhusky

Is it wise to leave a (fully charged) battery in a laptop while it is plugged into ac power plug. Will hurt or dimish the battery. Or is best use the ac plug and take the battery out while at home. I have a duo core chip.

look at your manual. some laptops say that the battery must be in while
running.

if it allows you to run without the battery in then you could leave it
out. keeping a Li battery fully charged and warm (which it is in
your plugged in running laptop) will shorten its lifetime. people
do remove their batteries to keep them cooler and hopefully
extend their lifetime. if you do so be careful with the battery,
if it came with a plastic cap on the terminals then use that, or
put in a nonconductive bag. in some fashion you need to
prevent the battery from accidentally shorting, not only
bad for the battery but you can start your house on fire.

if you run without a battery then you are loosing its
functioning as a UPS. if you run throught an external
UPS then you are still good for that.

[TRS-80 vet]

Originally Posted by Cyberianhusky

Is it wise to leave a (fully charged) battery in a laptop while it is plugged into ac power plug. Will hurt or dimish the battery. Or is best use the ac plug and take the battery out while at home. I have a duo core chip.

Depends on how long it is to remain on A/C while used. My dad's new Dell l'top suggests taking out the battery if the unit is more often used at home, on A/C power...