Macintosh Portable: Lead Acid Battery Alternative

If the lead acid battery of a Macintosh Portable is removed, and the
9-volt battery is replaced with an AC-to-9-volt adapter (plugged into the
wall), can the machine still run? This would allow the user to make the
Macintosh Portable a lighter, but transportable only, computer.

This article has been archived and is no longer updated by Apple.
Apple recommends that the Macintosh Portable NOT be used without the
internal lead acid battery. The battery is always in use even when the
Apple Power Adapter is connected.

The Apple Power Adapter provides 7.5 volts DC at a nominal current of 1.5
amps, peak of 2 amps. This adapter will not adequately power the Portable
without the lead acid battery installed.

It might be possible to use an AC/DC 9-volt adapter to power the system,
thus eliminating the need for the lead acid battery, but the only gain
from this would be the 3-pound reduction in the weight of the system.

Any weight savings obtained by removing the battery would be negated by
the size and weight of a 9-volt adapter of the appropriate capacity, and
not being able to use the machine without AC power available. These size,
weight, and convenience factors seem to be the primary reasons for having
a portable machine.

Published Date: Feb 18, 2012