Charge Voltage ??

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May 8, 2007 | 05:00 PM

scranage

Thread Starter

Burning Brakes

Joined: Nov 2005

Posts: 908

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From: Colorado Springs Colorado

Charge Voltage ??

Was driving into town when I noticed the voltmeter (both analog & digital) were low, at one point it dropped to 11.2. I was turning around to head home when it started to rise all the way up to 14.5. This was a 6 month old NAPA alternator, so I took it back and upgraded to the 140 amp one with the lifetime warrenty. This one is running between 13.7 and 14.5 Volts. WTF? aren't they supposed to hold right at 13.8 volts? Did I get another lemon, or does the voltage wander a bit above 13.8 normally?

May 8, 2007 | 05:14 PM

Vetterin

Drifting

Joined: Apr 2000

Posts: 1,879

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From: Lockport, IL Let's get em ALL home soon!

Alternators are supposed to charge between 13.5 & 14.5 volts ONLY.
Yours is working as it's supposed to.

May 8, 2007 | 05:18 PM

scranage

Thread Starter

Burning Brakes

Joined: Nov 2005

Posts: 908

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From: Colorado Springs Colorado

Really?? 14.5 seems too high...

May 8, 2007 | 05:28 PM

capevettes

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Quote:

Originally Posted by scranage

Really?? 14.5 seems too high...

I agree with the earlier poster. It appears to be within normal range. It depends on the state of charge of your battery whether it will be on the high or low side of normal.

May 8, 2007 | 07:03 PM

jfb

Team Owner

Joined: Mar 2001

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From: Cincinnati, Oh USA

GM says anywhere from 13 to 16 volts is ok. Cold, C4 alternators put out 14.7 volts and because of the 0.3 volts drop across the ignition switch contacts, your dash voltmeter will read 14.3 volts. As the alternator warms up, its voltage drops to 13.3 volts so that continued driving does not, "outgas" the battery which occurs when the charging voltage is 14.2 volts or higher on a near or fully charged battery.