Battery charging voltage question in cold temperature?

[DWG]

There are many people on this forum that have way more technical knowledge than me. So before going to the dealer I thought I would ask the forum. Has the software update for the BCM/PCM recall gone too far or is this normal operation for the BS?

I had the recall done on Aug 6 and never noticed a problem. In fact, the transmission has been shifting a little smoother after the relearning period was initiated by the software update and my gas mileage seemed to improve. This was probably more likely due to the engine breaking in since the car only had 1500 miles on it when the recall was done.

After reading about all of the battery issues on the forum I also got the cigarette lighter plug in voltage display that Dude recommended. Everything seemed to work normally over the summer (after the recall was done). The cranking voltage dropped a little from the 12.00 volt reading before starting the BS and the charging voltage was reading about 14.74 which is normal.

We just returned from vacation where the BS had sat in the unheated garage for about 9 days and the temperature had dropped to about 22 at night and in the 30’s and 40’s during the day. Since returning I have taken the BS out for a couple of drives of 30 to 40 miles even if we had nowhere to go so not to have the BS sit for long periods and to try and keep the battery charging. The BS started normally. I have the volt meter plugged in and cranking voltage only dropped into the 11.5 range but I noticed that the charging voltage has stayed at around 15.10 and after starting the BS initially went as high as 15.26 before settling back down to 15.10.

Googling the proper charging voltage says charging voltage should be below 14.7 and that 15.10 is overcharging the battery which could lead to premature battery failure. Does this sound right or is this normal for the BS? I have the EFB battery.

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[kshaw]

There are many people on this forum that have way more technical knowledge than me. So before going to the dealer I thought I would ask the forum. Has the software update for the BCM/PCM recall gone too far or is this normal operation for the BS?

I had the recall done on Aug 6 and never noticed a problem. In fact, the transmission has been shifting a little smoother after the relearning period was initiated by the software update and my gas mileage seemed to improve. This was probably more likely due to the engine breaking in since the car only had 1500 miles on it when the recall was done.

After reading about all of the battery issues on the forum I also got the cigarette lighter plug in voltage display that Dude recommended. Everything seemed to work normally over the summer (after the recall was done). The cranking voltage dropped a little from the 12.00 volt reading before starting the BS and the charging voltage was reading about 14.74 which is normal.

We just returned from vacation where the BS had sat in the unheated garage for about 9 days and the temperature had dropped to about 22 at night and in the 30’s and 40’s during the day. Since returning I have taken the BS out for a couple of drives of 30 to 40 miles even if we had nowhere to go so not to have the BS sit for long periods and to try and keep the battery charging. The BS started normally. I have the volt meter plugged in and cranking voltage only dropped into the 11.5 range but I noticed that the charging voltage has stayed at around 15.10 and after starting the BS initially went as high as 15.26 before settling back down to 15.10.

Googling the proper charging voltage says charging voltage should be below 14.7 and that 15.10 is overcharging the battery which could lead to premature battery failure. Does this sound right or is this normal for the BS? I have the EFB battery.

I wouldn't worry about a 15.1 charging rate. I have seen that on my Porsche many times.

 

[Ecom911]

Just had a spat of very cold temps -39c (-38f) and mine sat for 4 days, started and charging just fine @ 13.9 after a high of 14.8 after start. Cranking voltage will typically drop into those ranges and should recover quickly. Mine has been much better since the upgrade.

 

[Dude]

There are many people on this forum that have way more technical knowledge than me. So before going to the dealer I thought I would ask the forum. Has the software update for the BCM/PCM recall gone too far or is this normal operation for the BS?

I had the recall done on Aug 6 and never noticed a problem. In fact, the transmission has been shifting a little smoother after the relearning period was initiated by the software update and my gas mileage seemed to improve. This was probably more likely due to the engine breaking in since the car only had 1500 miles on it when the recall was done.

After reading about all of the battery issues on the forum I also got the cigarette lighter plug in voltage display that Dude recommended. Everything seemed to work normally over the summer (after the recall was done). The cranking voltage dropped a little from the 12.00 volt reading before starting the BS and the charging voltage was reading about 14.74 which is normal.

We just returned from vacation where the BS had sat in the unheated garage for about 9 days and the temperature had dropped to about 22 at night and in the 30’s and 40’s during the day. Since returning I have taken the BS out for a couple of drives of 30 to 40 miles even if we had nowhere to go so not to have the BS sit for long periods and to try and keep the battery charging. The BS started normally. I have the volt meter plugged in and cranking voltage only dropped into the 11.5 range but I noticed that the charging voltage has stayed at around 15.10 and after starting the BS initially went as high as 15.26 before settling back down to 15.10.

Googling the proper charging voltage says charging voltage should be below 14.7 and that 15.10 is overcharging the battery which could lead to premature battery failure. Does this sound right or is this normal for the BS? I have the EFB battery.

Although that voltage monitor claims “high accuracy” I probably would not use it exactly how you are … do you have an accurate volt meter with trusted accuracy? And there might be a voltage drop from the battery to the 12V port so I’d would connect an accurate volt meter directly to the battery termibalswith secure leads.

When interested in voltage drop while starting the vehicle, you could have an assistant start the vehicle while you use your phone to record a video of the accurate volt meter display connected directly to the battery - it’s also not perfect since I don’t know the video recording speed of your phone but you’ll get a general idea of the voltage drop when you look at the video later.

If you remain concerned about the battery voltage being too high when the alternator is charging, you would want to take the vehicle to the dealership for them to run a diagnostic on the charging system.

This says “(+-0.1Volt),” however mine stated +/-0.2V when i purchased mine…

[HIGH ACCURACY VOLTAGE MONITOR] Bright LED display monitor the voltage of the vehicle's battery with high accuracy (+-0.1Volt), easy and effective way to know the health of your car battery in real time.
https://a.co/d/0iSc8Lb

this link provides some tips and info on how I’d use the plug in voltage monitor:
https://www.broncosportforum.com/forum/threads/recall-work-failed.11628/post-198582

 

[mikeyncc]

Mine does the exact same thing, Temp dependent. Had I not installed Dude's voltmeter recommendation I would have had no idea. Last winter the high voltage was a concern but corrected itself with warmer weather.

 

[DWG]

Thanks for all the replies. Dude, thank you for the recommendations. I do not have a volt meter to attach to the battery. I am looking for some feedback before asking the dealer to check the charging system. I look at the plug in volt meter as a guide where if the numbers seem off I would need to go to the dealer and ask them to check the charging system.
mikeyncc I suspect that as you have experienced when the temperature warms up the charging voltage that is displayed will come down.

 

[sajohnson]

https://tengtoolsusa.com/blogs/news/12-volt-battery-charging-guidelines-for-cold-hot-weather

 

[Dude]

Score another win for:

 

[mikeyncc]

looks correct according to Google

“While a slight increase in voltage during cold weather is normal, if your alternator consistently reads above 15 volts even when the engine is warm, it could indicate a problem with the voltage regulator”

“During cold weather, charging voltage can increase into the 15-volt range to compensate for reduced chemical activity in the battery in sub-freezing temperatures. In any case, consult your service center”

Also low temperatures correlate with lower resistance.

 

[sajohnson]

That's why the lower the temp, the higher the charging voltage must be

 

[metalbender]

Probably not a voltage regulator anymore. Charging is controlled by the ecu.

 

[Dude]

You are right the battery charging voltage is computer controlled - PCM and or BCM since those were the subject of Recall 24S24

 

[DWG]

Looking at the chart the charging voltage of 15.10 at 30 degrees means that my Bronco Sport is operating normally. Thank you everyone for your responses.

 

[BLUEOVALRACER]

Has anyone had this recall done by a Technician at their House or at the Dealership?

 

[Dude]

Has anyone had this recall done by a Technician at their House or at the Dealership?

If you are referring to Recall 24S24, I had that done at my house by the dealerships mobile service. Took about 35 minutes with no issues. If Recall 24S24 is done per the listed steps in Recall 24S24, the transmission will enter a relearn cycle:

https://www.broncosportforum.com/forum/threads/ford-8f35-transmission-relearn-cycle.11467/

https://www.broncosportforum.com/forum/threads/resetting-the-ford-8f35-transmission.11466/

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