
THS II (TOYOTA HYBRID SYSTEM II)
02HTH41Y
HV Battery
DC / DC
Converter
Battery Temperature Sensor
THS ECU
Auxiliary Battery
288EG61C
(k
Ω
)
Resistance
0
Battery Temperature
(
C (
F))
TH-46
Auxiliary Battery Charging Control
1) General
The THS ECU controls the DC / DC converter in accordance with the signals from the battery
temperature sensor of the auxiliary battery, in order to control the charging voltage to the auxiliary
battery.
System Diagram
2) Battery Temperature Sensor
The battery temperaturesensor is installed on the battery.
The battery characteristic (battery internal resistance) of taking in current for charging varies according
to battery electrolyte temperature. If the electrolyte temperature is too low, the battery internal resistance
will increase, resulting in early deterioration. To prevent this, the battery temperature sensor changes its
resistance as shown below to detect the temperature.
Characteristic of Battery Temperature Sensor