Question: Alternator Issues?

[jwawhite]

Noticed on my DIC under the Voltage, the alternator is putting out 14.2 volts.

If my memory is correct, I believe it used to read over 13. volts, is there an issue coming up?

 

[Huskerman]

I think they will run from 13.7 to 14.7 depending on the load. Battery health can affect this I have read.......

 

[Hib Halverson]

If your alternator is generating 14.2v it is unlikely you have alternator problems.

 

[LLC5]

Noticed on my DIC under the Voltage, the alternator is putting out 14.2 volts.

If my memory is correct, I believe it used to read over 13. volts, is there an issue coming up?

Your reading are normal. When 14.2V is shown the battery is usually need of charging and it will charge up faster at that voltage, when the battery is full the computer will lower voltage to reduce battery gassing and improve mileage a fraction.

 

[jwawhite]

Thanks

For responding, I installed a new battery not too long ago, the correct large one, and let the Wife take it for the weekend to AZ.

She got caught in a 3 hour plus traffic jam on the 10 Frwy just outside Palm Springs. Cal Trans opened up the concrete roadway on Sat.

For some reason their supply of conrete was not available due to a breakdown so three lanes were taken away until late Sunday.

I am thinking there was a battery drain during that time and perhaps the Alt. is now trying to charge the battery.

Today I will check the levels of the battery (why don't they make sealed one?) and check the connections.

I don't believe since I've owned the car from late '03, I've seen such a high charge!

Thanks again...

 

[Curious George]

Alternator output / battery charging is also temperature dependent. For example, in the morning, the alternator output is high, especially in the winter time (region dependent, but in general, an accurate statement). As the vehicle / under the hood warms up, the alternator charge voltage will drop slightly.

Various factors will affect the final output voltage, but nominally, if the vehicle is up to operating temperature, the output voltage should read 13.5 ~ 13.8 typically while driving.

CG

 

[BigJimZ16]

Alternator output / battery charging is also temperature dependent. For example, in the morning, the alternator output is high, especially in the winter time (region dependent, but in general, an accurate statement). As the vehicle / under the hood warms up, the alternator charge voltage will drop slightly.

Various factors will affect the final output voltage, but nominally, if the vehicle is up to operating temperature, the output voltage should read 13.5 ~ 13.8 typically while driving.

CG

It's not that the battery/alternator act differently because they are cold, it's because the starter requires more current to turn over a cold engine and thus the battery is drained more during the start cycle and therefore charges at a higher rate, thus the alternator voltage output goes up to generate higher charge currents.

 

[Curious George]

It's not that the battery/alternator act differently because they are cold, it's because the starter requires more current to turn over a cold engine and thus the battery is drained more during the start cycle and therefore charges at a higher rate, thus the alternator voltage output goes up to generate higher charge currents.

Most (if not all) modern alternators (with internal voltage regulators) are temperature compensated. It is a known fact that a battery's charging needs will change depending on the ambient temperature range.

As an experiment, if you had two batteries in a vehicle and they were electrically isolated from each other, let's say Batt 1 and Batt 2.

Condition:
Both batteries fully charged and ready to go. Outside Temperature: 45*F

Batt 1 starts the vehicle, charging voltage after starting is 14.7VDC, Batt 2 is switched into the system the same time Batt 1 is switched out. You will notice hardly any change, if any, in the alternator voltage. Batt 1 will charge back up almost immediately (within a few minutes), if the vehicle started within a few seconds of cranking.

I suspect letting a sealed lead acid battery sit on bare concrete will somehow mysteriously drain all of the charge out of it, which is why you see people put 2x4 under a battery in the garage. :L

I am guessing this post will unleash a firestorm of rants, but maybe we will all learn something.

CG