Car: 2010 Mazda 3 GT 2.5L Manual 160,000KMs
I purchased the car 3 months ago not knowing the history of the battery, I wanted to test it.
I measured the voltage across my battery using a voltmeter directly connected to the battery terminals. The following are the readings under different conditions:
- Engine is not running = 12.6V
- Engine is running (idle ~800RPM) = 13.6V
- Engine RPM is kept at ~4000RPM = 13.6V
I do not have easy access to measure the voltage directly coming out of the alternator. From lot of articles I read from the internet, my voltage should be 14.0V when the engine is running.
Is this normal or does this indicate some issue with either the alternator or the voltage regulator? Do I also need to load test the battery?
Note: The car starts with no issues and there are no other indicators of a bad battery or charging system.