Variable Alternator Voltage

[RonAZ]

I am only on my second day of ownership, but I noticed the alternator varies in voltage. When engine is under power the voltage stays about 12.7 to 12.9 volts. When I let off and coast or step on brake the voltage rises to 14.1 volts. I am monitoring this on the small display between the tach and speedo.
Due others do this as well? Altenator was very hot when I got home this afternoon. I think I could smell it, but with all the new smells it is hard to be sure. Next drive I will take thermometer and measure the temp when I stop.
I have the tow package with higher output alternator.

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[Glamisfan]

My wife’s Cadillac does the same thing. Freaked me out. I was told it’s part of the mpg strategy. So probably the same thing?

 

[WXman]

Ford does it too. They call it the "battery management system". It's designed to maintain a minimum voltage on the battery to conserve fuel by not running the alternator at 100% all the time. The problem is, it won't keep the battery at the level that it could potentially be at, and a lot of guys were finding that they could not use vehicle accessories, radio, etc. for very long with the key off. So, most Ford owners I know would unplug the Hall Effect sensor on the battery cable to disable the system.

 

[Glamisfan]

I saw that sensor on our car. And the battery just went bad at 3 years, and was giving us some computer glitches/bugs before it finally wouldn’t start. So I’m not a fan of this new fangled technology!

 

[jeepardized]

Coincidence that batteries are now only lasting 3-4 years? I think not.

 

[mwilk012]

Coincidence that batteries are now only lasting 3-4 years? I think not.

This charging strategy will extend the life of the battery, not shorten it. Batteries don’t last as long anymore due to low quality work and materials.

 

[Wicked_JL]

My 2024 Rubicon XR with the 3.6 V6 non-e torque does the same thing since i got it last month. When driving i see 12.7 volts, as soon as i let go of the pedal it goes to 14.3 volts.

I think its normal

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