Toshiba T4500 User Manual page 21

Figure 1-13 Main Battery Circuit (Nickel Metal Hydride)
The T4500/T4600 Family's main battery has three devices to prevent circuit overload. Table 1-9
shows the overload specifications.
Table 1-9 Circuit Overload Protection Devices for Main Battery
Protection Method
Thermal protector
Electrical rating
Maximum circuit breaker current
Allowable operating temperature
Thermal fuse
Current rating
Voltage rating
Temperature rating
Thermal sensor
Load resistance
Operating temperature limits
Thermal protector
When the temperature falls outside the operating range of 60° to 75° C, the thermal protec-
tor reduces the current by increasing the internal resistance.
Thermal Fuses
If the temperature exceeds 91° C, the thermal fuses may blow to protect the battery and the
system.
WARNING: Never try to use a battery unless its fuses are intact. Do not try to replace a
battery fuse or try to bypass a fuse. Using a defective battery can permanently damage the
system and can cause injury.
Thermal sensor
The thermal sensor monitors the temperature of the battery.
T line
The thermal sensor monitors the temperature of the battery and changes the voltage in the T
line accordingly. The power supply microprocessor monitors the voltage changes in the T
(Nickel Cadmium/Nickel Metal Hydride)
Rating/Function
12 VDC, 3 A
12 VDC/120 A
60° ~ 75°
10 A
250 V
91° C
(Monitors the battery's temperature)
10 kΩ ±1% (at 25° C)
-50° ~ 100° C
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