Maybe having electrical trouble
Fleet Owner
Joined: Jul 2004
Posts: 27,294
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From: NM
After the battery is recharged (from starting), the regulator should sense that the battery is charged and taper down the voltage into the 13.2 range. Higher voltages will just boil the battery if continuously fed. It depends where the voltage is being measured, too. under the dash will be different that at the battery, depending on how the alternator output is routed.
Post Fiend
Joined: Apr 2002
Posts: 19,311
Likes: 97
From: Waterloo, Iowa
No, battery voltage at idle will be typically 13.8 to 14.3 volts at idle, no accessories on.
Remember even the ignition draws quite a few amperes. We want to see the charging system to be able to (roughly) maintain this, even with all the accessories on, at a good high idle.
In very hot temps maybe a little lower, and in cold temps higher. But, in the truck about 1 to 1 and 1/2 volts higher than the resting or open circuit voltage of the battery is a good rule of thumb.
http://www.aa1car.com/library/charging_checks.htm
Remember even the ignition draws quite a few amperes. We want to see the charging system to be able to (roughly) maintain this, even with all the accessories on, at a good high idle.
In very hot temps maybe a little lower, and in cold temps higher. But, in the truck about 1 to 1 and 1/2 volts higher than the resting or open circuit voltage of the battery is a good rule of thumb.
http://www.aa1car.com/library/charging_checks.htm
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