Highest Volts your ScanGauge at start up/ under operation? (1 Viewer)

[desmocruiser]

I have recently thought my alternator may be charging at too high a rate

After sitting for a week my ScanGauge peaked at 15.3 Volts, highest reading I have seen. It quickly (minute or so) settled to 13.9-14.3.

For the members with a ScanGauge or similar meter. What is the highest voltage reading?

After start up after a sitting for several days?

After start up when driven daily?


While operating for several hours?

Also if you have any modifications/changes to the charging/electrical system; dual batteries, different alternator, etc.

I have the stock alternator for a 97', dual Odyssey batteries, with a National Luna isolator.

Thanks!!!

 

[mingles]

14.6-14.8 on my old alternator as it was failing. New alternator has been rock solid 13.7-13.8 on scanguage for the last year. My scanguage typically reads a 1/10th of a volt lower that a secondary voltmeter I have directly tied to the battery.

There are too many variables to nail down as set voltage (temp of alternator, ambient temp, changing electrical load) but extended voltages above 15.0 are not healthy for your battery. Won't kill it immediately, but will over time.

 

[desmocruiser]

14.6-14.8 on my old alternator as it was failing. New alternator has been rock solid 13.7-13.8 on scanguage for the last year. My scanguage typically reads a 1/10th of a volt lower that a secondary voltmeter I have directly tied to the battery.

There are too many variables to nail down as set voltage (temp of alternator, ambient temp, changing electrical load) but extended voltages above 15.0 are not healthy for your battery. Won't kill it immediately, but will over time.

Thanks!

Yeah over 15 volts got my attention! To help narrow the variables it was warm I think the garage 75*+, it had been over a week since it had been started. I also noticed I had the lights in the parking light mode which will should trigger the alternator to max charge.

Thanks for sharing your readings as the alt was failing, I see mid 14’s pretty often. Typically runs 13.8-14.6.

I think I remember your thread, it has me keeping a closer eye on mine!

 

[TYM4FUN]

I have recently thought my alternator may be charging at too high a rate

After sitting for a week my ScanGauge peaked at 15.3 Volts, highest reading I had seen before. It quickly (minute or so) settled to 13.9-14.3.

For the members with a ScanGauge or similar meter. What is the highest voltage reading?

After start up after a sitting for several days?

After start up when driven daily?


While operating for several hours?

Also if you have any modifications/changes to the charging/electrical system; dual batteries, different alternator, etc.

I have the stock alternator for a 97', dual Odyssey batteries, with a National Luna isolator.

Thanks!!!

Same here. Over the last 6 months it had started creeping higher and higher. I am upgrading to Sequoia alternator, and I am guessing just in time. I am on my original 97 alternator...

 

[flintknapper]

Thanks!

Yeah over 15 volts got my attention! To help narrow the variables it was warm I think the garage 75*+, it had been over a week since it had been started. I also noticed I had the lights in the parking light mode which will should trigger the alternator to max charge.

Thanks for sharing your readings as the alt was failing, I see mid 14’s pretty often. Typically runs 13.8-14.6.

I think I remember your thread, it has me keeping a closer eye on mine!

^^^^

This consistent with I see. Stock 80 amp alternator (original). I've been running a ScanGauge for better than 6 yrs on it.

Never seen 15 volts. That would be kinda spooky.

 

[jonheld]

Alternator voltage output will vary based on state of charge of the battery and load. A healthy alternator should put out 14.4 VDC while charging and gradually decrease as the battery charges and/or as load decreases. If you are constantly seeing higher voltage, then the voltage regulator is failing.