Charging System: Description and Operation

CHARGING SYSTEM


System Description


DESCRIPTION
The alternator provides DC voltage to operate the vehicle's electrical system and to keep the battery charged.
The voltage output is controlled by the IC voltage regulator.
Power is supplied at all times
- through 10A fuse [No. 36, located in the fuse, fusible link and relay block (J/B)]
- to alternator terminal 4 ("S" terminal).
"B" terminal supplies power to charge the battery and operate the vehicle's electrical system. Output voltage is controlled by the IC voltage regulator at terminal 4 ("S" terminal) detecting the input voltage.
The alternator is grounded to the engine block.
With the ignition switch in the ON or START position, power is supplied
- through 10A fuse [No. 14, located in the fuse block (J/B)]
- to combination meter terminal 12 for the charge warning lamp.
Ground is supplied at signal
- to combination meter terminal 22
- through alternator terminal 3 ("L" terminal).
Then power and ground are supplied, the charge warning lamp will illuminate.
When the alternator is providing sufficient voltage with the engine running, the ground is opened and the charge warning lamp will go off.
If the charge warning lamp illuminates with the engine running, a malfunction is indicated.
Ground is supplied

MALFUNCTION INDICATOR
The IC voltage regulator warning function activates to illuminate the charge warning lamp, if any of the following symptoms occur while alternator is operating:
- Excessive voltage is produced.
- No voltage is produced.

POWER GENERATION VOLTAGE VARIABLE CONTROL SYSTEM
Power generation voltage variable control system that controls the power generation voltage of the alternator has been adopted. By performing the power generation voltage variable control, the engine load due to the power generation of the alternator is reduced and fuel consumption is decreased.






Operation Description
- The battery current sensor detects the charging/discharging current of the battery. ECM judges the battery condition based on this signal.
- ECM judges whether to perform the power generation voltage variable control according to the battery condition.
- When performing the power generation voltage variable control, ECM calculates the target power generation voltage according to the battery condition and sends the calculated value as the power generation command value to IPDM E/R.
- IPDM E/R converts the received power generation command value into the power generation command signal (PWM signal) and sends it to the IC voltage regulator.
- The IC voltage regulator controls the power generation voltage by the target power generation voltage based on the received power generation command signal.
- When there is no power generation command signal, the alternator performs the normal power generation according to the characteristic of the IC voltage regulator.

NOTE:
When any malfunction is detected in the power generation voltage variable control system, the power generation is performed according to the characteristic of the IC voltage regulator of the alternator.

Main Component Part

BATTERY CURRENT SENSOR





- Battery current sensor (1) is installed to the battery cable at the negative terminal, and it detects the charging/discharging current of the battery and sends the voltage signal to ECM according to the current value.