Some cars have a temperature sensor underneath the battery (Chrysler products)... I am not sure that Subaru does.Does my car have a battery temperature sensor, or is it another temp-related sensor somewhere else, that gives me this high cold-start charge?
I do know that some newer Subaru has a CURRENT sensor on the battery-negative terminal. The computer will boost alternator output based on electrical load.
Some common electrical loads which will increase alternator output:
- Starting engine.
- Obviously, starting engine drains battery hence there is high electrical load for several minutes after starting.
- Cold ambient temperatures demands more battery power hence increases this temporary alternator boost
- Headlights ON
- Blower on HIGH
- A/C ON
- do not forget that turning on AC also turns on both radiator fans.
- Rear window defrost ON
- windshield defrost ON
- remember that windshield defrost also turns ON A/C (ref. A/C above)