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APPENDIX IV
BATTERY STORAGE AND USE
A battery will lose a portion of it’s charge when not in use. Some of
these losses can be reduced and some can not. The chart on page 26
shows the effect of the losses on the charge retained by the battery.
A. Self Discharge- Nickel Metal Hydride batteries lose about 20%
of their charge in the first two weeks of storage due to internal self
discharge. After which they loose approximately 10% per month. This
rate of loss increases with an increase in storage temperature. We do
not recommend storing batteries in a refrigerator because of potential
moisture problems. Avoid storage in automobiles and other places
where sunlight can elevate the temperature.
B. Intelligent Battery Circuit Power- The microprocessor based
monitoring circuit of the Intelligent Battery uses a small amount of
power as it periodically updates the memory. This power is used at all
times, even in storage. It can not be turned OFF.
C. Computer Standby Power- The PowerBook drains a small
amount of power from the internal batteries when it is in the sleep and
OFF modes. Removing the battery from the computer when it is not in
use will eliminate this power loss.
D. Other Power Use- The PowerCenter and most other external
chargers will use a small amount of power from the battery when there
is no input power source connected . The power used by the
PowerCenter is about half that used by the PowerBook in sleep mode.
It is recommended that batteries be removed from the PowerBook and
any other equipment if the batteries will not be used for over a week.
Note that Batteries can be left in the PowerCenter if input power is
applied to the charger. The PowerCenter applies periodic charge
maintenance pulses to compensate for losses in storage and keep the
battery charge near it’s maximum.
