Battery Voltage is questionable - What is yours?

[AverageWhiteGuy]

Agreed. I mentioned this in another thread. When a battery is burdened with a load, it reads low. When you turn off your car, and only a few things are burdening the battery, the voltage will read high.

The only reason the voltage is alot higher when your car is on, is because the alternator is charging the battery, and providing some power as well. Here's some example alternators from earlier Ford Rangers;
https://www.therangerstation.com/tech_library/alternator.shtml

It's important to note, as the wattage of the alternator goes up, the load on your engine will also increase. I'd say leave it alone, till you run into problems. I own a NOCO GB70 (2,000 Amp) Car Battery Jump Starter. Bought it for $160, two years ago during black friday from autozone. (20% off coupon)

I just keep it in my car, once in awhile I usb charge the GB70, to make sure it's good to go. Already helped out 3 neighbors who had dead batteries. When my car battery goes out in my ford, and it's past the 3 yr warranty. I'll probably buy the motorcraft AGM, assuming they continue with a 3 year warranty. Seems ok to me

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[charwest]

Came home after 3 week vacation and the Ranger battery barely able to start engine. Used truck for two days , but battery did not recharge. Dealer replaced it under warranty.
So, if I leave the Ranger parked at the airport for a two week trip, do I have to disconnect the battery to avoid a dead battery when I get back ??

one data point: we just picked up our truck after shipping it across the pacific. battery 16k miles old, and then it sat in a shipping container for 9 weeks. started right up today. maybe we got lucky.

 

[t4thfavor]

The Ranger has a battery management system which is pretty smart. It is not your father's charging system on his 1974 Plymouth Valiant. In an effort to improve mileage manufacturers are finding ways to lighten their vehicles. Smaller, lighter AGM (soon Lithium Ion) batteries are part of this. They aren't charged in the same fashion as that big old lead acid battery in dad's car. So don't get wierded out if you see voltages other than dad's. My truck can set for a week and starts up fine. I run a 50-watt ham radio in it and it handles the load fine.

Does your radio turn off and back on every time the auto start/stop triggers? Mine does and it’s ungodly annoying. The battery voltage drops to 9v during starts which has literally never happened on any of my previous cars with radios installed. I even had a diesel jeep which started with no radio problem, and the battery in that was 10 years old.

 

[JKocot]

Does your radio turn off and back on every time the auto start/stop triggers? Mine does and it’s ungodly annoying. The battery voltage drops to 9v during starts which has literally never happened on any of my previous cars with radios installed. I even had a diesel jeep which started with no radio problem, and the battery in that was 10 years old.

I normally hit the button to turn the ASS off every time I drive, but on the occasions I forget and it does go off, my radio has never turned off.

 

[t4thfavor]

I normally hit the button to turn the ASS off every time I drive, but on the occasions I forget and it does go off, my radio has never turned off.

I have a Kenwood D710GA, I'm told they are sensitive, but the voltage should not drop below 10V on a start for any car with a good battery.

 

[JonB]

Does your radio turn off and back on every time the auto start/stop triggers? Mine does and it’s ungodly annoying. The battery voltage drops to 9v during starts which has literally never happened on any of my previous cars with radios installed. I even had a diesel jeep which started with no radio problem, and the battery in that was 10 years old.

Sorry for the delayed response to your question. I turn my radio off before shutting down the truck. Voltage does drop when starting the truck, though dropping to 9 volts seems low. Voltage that is beyond the range acceptable to the radio can damage it, so I always turn it off before shutting the truck down and don't turn it back on until the truck has started.

 

[HarryD]

It might have something to do with the Battery Management System.
I had the connector at the back of the battery unplugged, which disabled the ASS. I just plugged a voltmeter adapter into one of the DC outlets on the dash and while driving around it measured around 14.2V. I then plugged the BMS connector in and it read around 14.5V for a day or so and then dropped to around 12.8V. while still driving around with a sporadic 14.+V reading.
After unplugging the connector the gauge bumped up to around 14.5V and has been holding steady for a week now.

 

[RoadBoss]

It might have something to do with the Battery Management System.
I had the connector at the back of the battery unplugged, which disabled the ASS. I just plugged a voltmeter adapter into one of the DC outlets on the dash and while driving around it measured around 14.2V. I then plugged the BMS connector in and it read around 14.5V for a day or so and then dropped to around 12.8V. while still driving around with a sporadic 14.+V reading.
After unplugging the connector the gauge bumped up to around 14.5V and has been holding steady for a week now.

If that connector has something to do with the voltage regulation, you could end up destroying your battery if it's getting constantly over charged. IMO, I wouldn't mess with Ford's very advanced charging system just because it doesn't operate the same as a 1995 F150.

 

[Markjr]

Using the volt meeting in Torque/OBD2AA its ~12V not running and ~14+ running. Pretty typical values in my experience.

Was wondering how did you get torque to show you the truck radio thanks

 

[micl9]

Was wondering how did you get torque to show you the truck radio thanks

OBD2AA
Thread HERE

 

[WOADKIL]

SemperVee,

Very informative, thanks!

 

[micl9]

OBD2AA
Thread HERE

just noticed the link didn't work - Now fixed

 

[charwest]

one data point: we just picked up our truck after shipping it across the pacific. battery 16k miles old, and then it sat in a shipping container for 9 weeks. started right up today. maybe we got lucky.

Second data point. We shipped our car back- about seven weeks without a start and again started right up.

I suspect the system knew it was running lower battery than usual as the auto stop didn’t turn the car off at stops for the first day or so of driving afterwards.

 

[fjwlobo]

Has anyone noticed if the ASS is disabled with the meter installed in place of the 12V power outlet?

 

[charwest]

Has anyone noticed if the ASS is disabled with the meter installed in place of the 12V power outlet?

not sure what you mean, but I removed a 12v cig socket from the dash and replaced with a voltmeter and my auto start/stop works normally as far as I can tell.

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