Applies to any powerbook or iBook any version of the Mac OS.
Owning a portable computer can be a truly useful thing. Being
able to take your work everywhere is great. Of course, having a
portable computer is hardly any good if you don't have a decent
battery to power it.
Since Apple has been making portable Macs, they have used 4
types of batteries. Here is a brief run-down of each type used,
the models they are found in, and how to properly care for each
type of battery:
Sealed Lead Acid (SLA)
Used In: Macintosh Portable, PowerBook 100
By far, the oldest (and most rare) type of battery. Not used any
more, and almost impossible to find. Since they were used on
only 2 types of Macs, most people don't need to worry about this.
You should recharge a Lead Acid battery whenever it runs low
on power. Never allow the charge to become fully depleted. If
this occurs, the electrodes in the battery will break down, making
it impossible for the battery to ever hold a charge again.
Still very old, though newer and not nearly as rare as the Lead
Acid
battery. Not used any more, but you can still find replacements if
you need one, though they tend to be costly.
NiCad batteries suffer from a potentially harmful problem known as
the "memory effect". If the battery is only partially drained,
then re-
charged, the battery will think that the level to which it was
drained
was actually empty, even if it wasn't. Though this doesn't happen
after only one or two times, it can still occur rather easily;
usually
after 30 days or so of recharging from non-empty.
Example: Say that your battery normally gets 3 hours of use from a
100% (full) charge. If you use your PowerBook for only an hour and
a half a day (draining the battery to 50%), and then recharge it,
you
will find that after a month or so, you will only get an hour and
a half
of use from a fully-charged battery.
There is, however, a cure for this. By completely draining the
battery
(to the point it no longer has enough power to run the computer),
and then re-charging it, it will eliminate the effect of the
memory
effect. Apple recommends doing this once every 60-90 days, and
includes a utility on these models which will help you do so.
Nickel Metal Hydride (NiMH)
Used in: PowerBook 190, 280, 280c, 520, 520c, 540, 540c, 2300c,
5300, Duo 210, Duo 230, Duo 250, Duo 270c
For practical purposes, NiMH batteries hardly differ from NiCad
batteries. They should be charged when depleted, and also suffer
from the memory effect. Apple recommends completely draining
and recharging the battery every 30 days.
Lithium Ion (LiIon)
Used in: PowerBook 2400, 3400, all PowerBook G3 series, all
PowerBook G4 (Titanium) series, all iBooks (including both the
original Clamshell style and "Dual USB" models.)
The most recent, modern battery, still being used today. These
provide superior power and battery life, and suffer no problems,
such as the memory effect. They should be recharged when they
become depleted, but can also be charged at any point in time.
