Toshiba T4900CT Manual page 17

Trickle Battery Charge
When the main battery is fully charged and the AC adapter is attached, the micropro-
cessor automatically changes quick charge 1 or 2 to trickle charge.
Detection of full charge
A full charge is detected only when the battery is charging at quick charge. A full
charge is detected under any of the following conditions:
1. A battery voltage fall is detected.
2. The charging time exceeds the fixed limit.
3. The thermal rise (+DT) exceeds the fixed limit.
4. The battery's temperature is over 60°C.
1.8.3 Backup Battery
The backup battery maintains data for AutoResume. The power source used to back-up the
AutoResume data is determined according to the following priority:
AC adapter > Main battery > Backup battery
The backup battery is charged by the main battery or AC adapter when the system power is
turned on and off. Table 1-8 shows the charging time and data preservation period of the
backup battery.
Table 1-8 Backup battery charging/data preservation time
Charging Time
Data preservation period (full charge)
1.8.4 RTC battery
The RTC battery provides power to keep the current date, time, and other setup information
in memory while the computer is turned off. Table 1-9 shows the charging time and data
preservation period of the RTC battery.
Table 1-9 RTC battery charging/data preservation time
Charging Time
Data preservation period (full charge)
T4900CT
Power On
Power Off
Power On
Power Off
1 month
Time
3 H
3 H
3 H
Time
24 H
24 H
1-17