batteries

My friend's iBook is always plugged into the mains - it's his office machine, if he needs to take files home he uses his iPod. Should he remove the batteries?
Stewy wrote on :

I forgot to post this query in my previous post.

My friend's iBook is always plugged into the mains - it's his office machine, if he needs to take files home he uses his iPod. Should he remove the batteries?

John Johnson replied on :

In article anyone4tennis-ABD459.10260622022006@redacted.invalid, Stewy anyone4tennis@redacted.invalid wrote:

I forgot to post this query in my previous post.

My friend's iBook is always plugged into the mains - it's his office machine, if he needs to take files home he uses his iPod. Should he remove the batteries?

And do what, sell it (or does he have more than one iBook)? If the time that your friend spends worrying about whether or not to remove his battery is a large percentage of the probably time spent on battery power, don't mess with it.

Ok, that's a bit flip, but really: why bother? Sure, I know about optimizing storage ("batteries don't like heat!") and such, but if the battery wears itself out on the shelf, instead of inside the computer, what have you gained? Furthermore, if you remove the battery, you don't get to spontaneously decide to take the iBook to another desk or conference room or something.

There are situations where a benefit might be obtained by removing the battery for storage. Unless you give us some more details, I don't see any benefits for the user in this situation.

fwiw, here's Apple's documents on batteries: http://www.apple.com/batteries/notebooks.html http://www.apple.com/batteries/

Lars Goldschlager replied on :

On Tue, 21 Feb 2006 21:26:06 -0400, Stewy anyone4tennis@redacted.invalid
wrote:

I forgot to post this query in my previous post.

My friend's iBook is always plugged into the mains - it's his office machine, if he needs to take files home he uses his iPod. Should he remove the batteries?

Btw he should unplug the iBook once a month or about that, and let the
battery discharge completely or until it asks to be plugged on or turned
off. That way the battery should last a little longer.

Gnarlodious replied on :

Entity Lars Goldschlager uttered this profundity:

Btw he should unplug the iBook once a month or about that, and let the battery discharge completely or until it asks to be plugged on or turned off. That way the battery should last a little longer.

I don't believe it.

-- Gnarlie

John Johnson replied on :

In article C02A5C24.145A9%gnarlodious@redacted.invalid, Gnarlodious gnarlodious@redacted.invalid wrote:

Entity Lars Goldschlager uttered this profundity:

Btw he should unplug the iBook once a month or about that, and let the battery discharge completely or until it asks to be plugged on or turned off. That way the battery should last a little longer.

I don't believe it.

-- Gnarlie

It's in Apple's official recommendations. Note that this procedure does two things:

  1. It does help prevent the formation of unwanted Lithium compounds in the battery (such formation can lower capacity).
  2. It provides the computer with an update of its charge calibration (since total capacity and other characteristics change as the battery ages, whether you use it or not, whether you charge it or not), which allows both accurate "time remaining" calculations and accurate charging (and preventing over-charging and under-charging is important). I don't know whether #1 is more important than #2, but I know that consistent over- or under-charging of a Li-chemistry battery will trash it pretty quickly.

It's also true that some battery chemistries deal with being constantly topped off than others. Even within the same chemistry (e.g. among lead-acid batteries), if you're building one for use in a situation where it will be on the charger all the time, you design it differently than if it gets discharged fairly deeply often.