Battery Charging Control - Toshiba T4500 User Manual

line.
S line
The power supply microprocessor determines the type of battery by whether the S line is
connected to the battery circuit. If the S line is connected to the negative line, the power
supply microprocessor determines that a Nickel Metal Hydride Battery is installed in the
computer. If the S line is not connected, the power supply microprocessor determines that a
Nickel Cadmium Battery is installed in the computer.
1.9.2

Battery Charging Control

Battery charging is controlled by a power supply microprocessor that is mounted on the power
supply. The microprocessor controls whether the charge is on or off and detects a full charge when
the AC adapter and battery are attached to the computer. The system charges the battery using
quick charge or trickle charge.
Quick Battery Charge
When the AC adapter is attached, there are two types of quick charge: quick charge 1 when the
system is powered off, and quick charge 2 when the system is powered on.
Quick charge 1
(power off)
Quick charge 2
(power on)
NOTES 1: The time required for quick charge 2 is affected by the amount of power the
system is consuming. Use of the fluorescent lamp and frequent disk access
diverts power and lengthens the charge time.
2: Using quick charge 1, the system CPU automatically stops the charge after
two hours regardless of the condition of the battery.
If one of the following occurs, the battery quick-charge process stops.
1. The battery becomes fully charged
2. The AC adapter or battery is removed.
1-22
Table 1-10 Quick Charge Times
Kind of battery
Nickel Cadmium
Nickel Metal Hydride
Nickel Cadmium
Nickel Metal Hydride
Charging time
About 1 hour, 10 minutes
About 1 hour, 30 minutes
1.5 to 4 hours (typical: 2 hours)
1.5 to 5 hours (typical: 3 hours)