maintaining laptop battery life (1 Viewer)

[santaslayer]

Is it generally better to leave the laptop in the power supply if you are using your laptop at home, or would you recommend unplugging it out of the power supply everytime I turn my computer off?

 

[MedNez]

Well, a few tips to keep your battery life long:

• \edit\ Approximately 40% battery level is a nice level to keep the battery stored at.
• If you're not using it for a while, leave the battery fully discharged.

In your case, if you're using an AC adaptor for a while, unplug the battery. Why? Because if you leave it plugged in while the AC is on, the battery will continue to trickle charge, keeping it topped up, but can ultimately reduce the life of your battery.

And if you're using the AC power without the battery, then when you turn the computer off, as long as the battery isn't in the computer, whether the AC is plugged in or not won't affect it. If the battery is plugged back in (assuming it's fully charged), then unplug the AC power.

 

[Templar]

It shouldn't matter as most laptop batteries are lithium ion and it should automatically stop recharging. Plus fully discharging a lithium battery is unnecessary and may shorten its life.

 

[velox]

Yeah i think what MedNez is talking about is only applicable for NIMH batteries.

 

[sunny]

It shouldn't matter as most laptop batteries are lithium ion and it should automatically stop recharging.

This is not a feature of the chemistry of the battery. They fall into a category called "smart batteries". Most batteries of this type can predict the charge level with much higher accuracy and prevent charging when already charged to prevent overcharging. So unless the lithium ion battery is a smart battery, it can still overcharge.

 

[AntiHyper]

I have this thing called UnInterruptable Power Supply (UPS) under the power settings for my computer
Is it a kind of those lithium battery?

 

[sunny]

I have this thing called UnInterruptable Power Supply (UPS) under the power settings for my computer
Is it a kind of those lithium battery?

If you have a UPS you should know it. A UPS is a kind of backup power supply for a computer if there is a black out or some other power outage. They might use different types of chemistry called sealed lead acid, much like a car battery.

 

[MedNez]

Yeah i think what MedNez is talking about is only applicable for NIMH batteries.

Negative.. I just finished a modules worth of chemistry notes yesterday.. unfortunately I now retain useless knowledge about Li-ion batteries. Trickle charge occurs in these (not NiMH rechargeable batteries), as you might notice with mobile phone batteries too.

Plus fully discharging a lithium battery is unnecessary and may shorten its life.

Overcharging is about the only thing you can do routinely to shorten the life of your battery. Li-ion batteries degrade with time, that's it. Not the number of charge cycles, not the amount of charge left when you use it. The life of the battery is determined more or less by it's manufacturing date

 

[golfstick]

if you're talking hsc chem then you wouldn't know the li-ion battery well enough to understand that the cells in it require charge to keep the cells 'alive', as such

that's exactly why apple stress that it's important not to fully discharge the iPods li-ion battery, and that charging when half-full has no greater impact on the overall life of the battery compared to doing a complete charge. they reccommend fully discharging the battery only once every 30 charge cycles or so, and only to re-calibrate the battery meter. laptop batteries are similar

the 2nd or 3rd hit on google returned this

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

and
http://www.apple.com/batteries/notebooks.html

 

[MedNez]

and that charging when half-full has no greater impact on the overall life of the battery compared to doing a complete charge

Yes, thanks for a re-hash. As I said, Li-ion batteries have a somewhat limited lifetime, although you're more likely to buy a new device than to get a new battery, these days. Once the battery is produced in a factory, the electrolyte slowly eats away at the positive plate and the electrolyte decays. Thefore, resistance inside the battery increases. Over time, this resisitance builds up to a stage where the battery is no longer providing energy to the device.

Charge cycles for an average user will do little to affect the life of their battery. Unless it's damaged somehow.

 

[santaslayer]

OK, so the conclusion to the original question is?

 

[MedNez]

Unplug the AC when you turn the computer off