Battery Charger

On my Buick Enclave, 2008, I notice a few things regarding the panel volt meter while driving. About half the time, after starting the engine, the panel meter goes to a position (let's say at the 2:00
o'clock position, 14.5 vdc using my DVM) then settles to the 3:00 o'clock position within 5 or so miles, and at that point measuring 13.1 vdc. I figure that's about right for a trickle charge. (I take these meter measurements when arrive in my garage.)
The other half of the time, the meter sits at 14.5 vdc for hours. As an example, on a 125 mile trip I made on Christmas, the meter sat at 14.5 vdc all the way and I would have thought it would have gone to the 3.1 vdc trickle charge after a short while. Other times when I drive 40 miles to the neighboring town, the meter never goes to the 3.1 vdc point and hangs in at the 4.5 vdc point.
My question is, would a continuous charge at 14.5 vdc cause any overcharging resulting in a shorter battery life?
The operation conditions are daytime, no headlights or any other accessories, radio and gps on and no other things running except what is required to operate the car.
My knowledge is a little thin on these matters.
I am probably over analyzing this (a little too wordy) but I thought I'd ask.
Dave C.
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Dave C. wrote:

Any difference in outside temperature on the days that the voltage is higher? The regulator on that vehicle is controlled by the ECM and it will bump up the charging voltage to compensate for colder temperatures as well as for extra current draw. I wouldn't worry about it myself.
--
Steve W.

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All electronic voltage regulators that I am aware of are temp compensated whether internal, external, or in the PCM. Chryslers have been in the SMEC/SBEC (ECM) since the days of feedback carbs.
Where his is different is that the PCM can drop the voltage to reduce the load on the engine.
Also 14.5 is fine for the stock battery assuming the Delco/Delphi batteries are still lead/calcium instead of lead/antimony for the plate grids. My '97 Lumina with added CS144 140A alternator and remote sense wire hooked to the jump start terminal runs 14.9V when cold below freezing.
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Ah, therein lies part of the answer. Most of my recent observations have been at lower temperatures. Here in New England the temperature has been in the 30s by-and-large and below freezing.
Thanks for putting my mind at rest. I'll wait until warmer weather arrives. (I consider myself somewhat of a 'worry wart.' I recall many years ago when the battery was up to charge, it went into trickle.) Everything on the car now is computer interfaced. Even the panel analog-looking volt meter is also in that I see it's movement in a digital or discrete fashion, if you know what I mean.
Regards,
Dave
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On Fri, 14 Jan 2011 20:25:32 -0800, Dave C. wrote:

Accessories are designed for 12-16vdc and should operate properly at 14.9 volts. -- pj
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One should also consider the factor that the dash volt meter is likely not accurate to more than about 10%. So that 14.5 volt display could just as easily be 13.2 or 15.9, or anywhere between. To be sure, one should use a known accurate voltmeter and measure the voltage at the point where it is critical, often at teh battery terminals.
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