Alternator output? - Toyota Yaris Forums

tommyssa10 · 06-17-2016, 04:46 PM

I work for AAA and shits and giggles I decided to test the battery on my yaris(it's an original on a 2010 yaris with 27k miles) the battery came up bad(not surprised but it still holds enough cca to start the vehicle not a concern) the alternator test came back with the alternator charging at 13.3 unloaded and 13.4 under load. Is this normal for this car? Just curious I've noticed no problems starting or dim lights
just curious about the voltage. Thanks!

Tapokata · 06-17-2016, 06:49 PM

That's typical of the voltage that I see reported back through a ScanGauge on my 09.

dj92 · 06-18-2016, 08:10 AM

At least mine changes the output voltage according to several factors (engine load, battery temperature, headlight status).
It ranges from slightly above 12V to 14V, but the battery is 7 years old now and still fine.

tommyssa10 · 06-18-2016, 08:17 AM

Thanks for the input guys! yeah the stock batteries hold up surprisingly well!

Bluevitz-rs · 06-18-2016, 10:03 AM

It's strange with batteries in newer cars. There can be enough power to start the engine but as it cranks can drop low enough to mess up other electronics.

I know on my '05, when the key is turned to the ON pos, and the doors are closed, the door lock. When the car is turned off, the doors unlock. When my battery started getting really low a few years ago in the crazy cold weather we had, my door would lock, but not unlock when turned off.

I've also heard of other with stage behaviour all caused by low batteries.

And you should be testing the charging system at 2000rpm as least. Idle voltage can vary too much depending on battery status and load.

06-17-2016, 04:46 PM	#1
tommyssa10 Drives: 2010 Yaris S Join Date: Jun 2016 Location: Philadelphia Posts: 16	Alternator output? I work for AAA and shits and giggles I decided to test the battery on my yaris(it's an original on a 2010 yaris with 27k miles) the battery came up bad(not surprised but it still holds enough cca to start the vehicle not a concern) the alternator test came back with the alternator charging at 13.3 unloaded and 13.4 under load. Is this normal for this car? Just curious I've noticed no problems starting or dim lights just curious about the voltage. Thanks!

06-18-2016, 08:10 AM	#3
dj92 Embracing Curves View User's Garage Drives: '14 Prius Executive Join Date: Aug 2013 Location: mid-western Germany Posts: 256	At least mine changes the output voltage according to several factors (engine load, battery temperature, headlight status). It ranges from slightly above 12V to 14V, but the battery is 7 years old now and still fine. __________________ I drive, therefore I am.

06-17-2016, 06:49 PM	#2
Tapokata Drives: 2009 Yaris Join Date: Dec 2008 Location: Sacramento, CA Posts: 39	That's typical of the voltage that I see reported back through a ScanGauge on my 09.

06-18-2016, 08:17 AM	#4
tommyssa10 Drives: 2010 Yaris S Join Date: Jun 2016 Location: Philadelphia Posts: 16	Thanks for the input guys! yeah the stock batteries hold up surprisingly well!

06-18-2016, 10:03 AM	#5
Bluevitz-rs 1NZ-6spd View User's Garage Drives: '05 6-Spd Vitz RS Join Date: Oct 2008 Location: Oshawa, Ontario, Canada Posts: 2,967	It's strange with batteries in newer cars. There can be enough power to start the engine but as it cranks can drop low enough to mess up other electronics. I know on my '05, when the key is turned to the ON pos, and the doors are closed, the door lock. When the car is turned off, the doors unlock. When my battery started getting really low a few years ago in the crazy cold weather we had, my door would lock, but not unlock when turned off. I've also heard of other with stage behaviour all caused by low batteries. And you should be testing the charging system at 2000rpm as least. Idle voltage can vary too much depending on battery status and load.