Low battery voltage?

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Braaaaptor

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Need some advice on a possible battery issue I just noticed today.

IIRC the usual voltage according to the instrument panel is 14V on the dot. This morning as I headed to work it was down around 12V with occasional spikes to 12.5/13/and 14.5.

Anyone experience this and is there any detriment to the truck if I keep running this battery?

Truck is 4 months old w/7500mi
 

adllewis42

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Mine varies all the time but I've always presumed it's due to the car charging the battery or not. I run a fridge in the bed of the truck and if I haven't started the truck in a few days, I've seen it show 14.5V before.
 

FordTechOne

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Normal.

If there is a fault with the charging system, you’ll get a warning light and warning message in the Instrument Panel Cluster.

The system is what was called “Smart Charge” in previous generations. The PCM controls the generator based on current engine and electrical load conditions. The system is designed to reduce parasitic loss and maximize generator and battery life. No need to worry unless you get a warning indication.
 
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Braaaaptor

Braaaaptor

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Awesome, thank you both for the replies! I think reading these forums has made me hypersensitive about everything on this truck :D
 

Just_in_time

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The “battery” voltage read on the display is actually “battery system” voltage - the battery at its terminals would never read 12 volts. A normal lead acid at room temperature just sitting there should be roughly 2.1 or 2.2 volts per cell. (12.6 to 13.2 volts).

you also would not see 14.5 volts across the battery unless you like to live dangerously . Hence, the battery measurement point is at some point where there is a resistance between this point and the actual battery. The battery has a series element used to measure the current thru it - this device may have a voltage drop that is being included in the “battery” measurement display.

The way I read the “battery” voltage display - the higher voltages simply mean the charger is charging - the lower voltages mean the charger is not charging. Voltage less than 12.6 means the charger is not charging but the battery “system” is outputting current - such that at the measurement point the battery “reads” less than 13.2...

bottom line - you need to get a DVM right across the battery terminals to determine the actual battery voltage and not the “battery system” voltage.
 
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