Toshiba Portege 2000 Maintenance Manual page 28

1 Hardware Overview
1.6.2 Battery Charging Control
Battery charging is controlled by a power supply microprocessor. The power supply
microprocessor controls power supply and detects a full charge when the AC adaptor and
battery are connected to the computer. The system charges the battery using quick charge or
trickle charge.
Quick Battery Charge
When the AC adapter is connected, normal charging is used while the system is
turned on and quick charge is used while the system is turned off or in suspend mode.
(See Table 1-7)
Table 1-7 Time required for charges of main battery
Quick battery charge is stopped in the following cases.
1. The main battery is fully charged
2. The main battery is removed
3. Main battery or AC adapter voltage is abnormal
4. Charging current is abnormal
Trickle charge
When the main battery is fully charged and the AC adapter is plugged in, the power
supply microcontroller automatically switches from quick charge to trickle charge.
1.6.3 RTC Battery
The RTC battery provides the power supply to maintain the date, time, and other system
information in memory. Table 1-8 lists the battery charging time and data preservation times.
Table 1-8 RTC battery charging/data preservation time
Charging AC adapter or main battery in use
Data preservation time (when fully charged)
1-16
Normal charge
Quick charge
Charging Time
About 2 to 4 hours
About 2 hours
8 hours (approx )
Portege 2000 Maintenance Manual (960-333)
1.6 Batteries
Time
1 month