HYBRID 12V Battery Mystery SOLVED

[samspritzer]

The battery is not fine. How are you determining that it is fine?

I've had the truck four years and am still on the original battery. As I said, it goes into deep sleep mostly when its cold out....30s or lower.

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[goulaigan]

I don't have a 25 or 26. So I don't have the exact steps.

But you just need to customize your trailer settings in one of the trailer menus. Set it to shortest trailer allowed.

If you can put in zero feet, do that.
If it needs a positive integer, put in 1 foot.

Then your blind spot and cross traffic alerts won't be affected by your hitch light. Some folks put on bike racks with integrated lights. Ford started to acknowledge this possibility in 2025.

The older trucks simply turn off alerts.

Thx for the reply!
Unfortunately its not that easy. In the trailer "set up/configuration" you can choose "no active trailer" that was my first choice but didn't work (cross traffic still turns off)
Next I tried to configure a trailer with all dimensions as small as possible - same result.
Guess I'll just leave the hitch light unplugged until the first service......

 

[Mavster Mechanic]

Thx for the reply!
Unfortunately its not that easy. In the trailer "set up/configuration" you can choose "no active trailer" that was my first choice but didn't work (cross traffic still turns off)
Next I tried to configure a trailer with all dimensions as small as possible - same result.
Guess I'll just leave the hitch light unplugged until the first service......

What is the shortest trailer it will accept?

You should be able to use that.
Something's fishy.

Blind spot works though, correct?

 

[goulaigan]

What is the shortest trailer it will accept?

You should be able to use that.
Something's fishy.

Blind spot works though, correct?

Thanks for your interest David.

There are several parameters. Length, width, height, weight etc. I chose the smallest number available for each of the parameters.
I assume the cross traffic alert doesn't work while the hitch light is plugged in because, a notice appears on the instrument cluster indicating cross traffic has been disabled. Also a "Cross traffic alert disabled" notice appears until acknowledged. (Same on every restart if the hitch light remains plugged in)
Also, if you attempt to scroll through the settings to turn the "cross traffic alert" on manually, the option is "greyed out" as not available.
It seems to me that the "no active trailer" option should be the answer. Maybe a glitch waiting for an update....

 

[rslilly76]

Well here's the latest numbers from today.

The dc/dc charge amps stay between 15-30 mostly all day. However, if the AC is on full blast, headlights are on, radio on it can jump to 50-60 amps. However, if only 1 of those 3 are true it stays 30 amps or under typically. I don't think the triggers are the same on the 25 the way mine is acting.

 

[Mavster Mechanic]

Well here's the latest numbers from today.

The dc/dc charge amps stay between 15-30 mostly all day. However, if the AC is on full blast, headlights are on, radio on it can jump to 50-60 amps. However, if only 1 of those 3 are true it stays 30 amps or under typically. I don't think the triggers are the same on the 25 the way mine is acting.

Is vehicle battery current ever anything other than 1?

Look for it in the first couple of minutes after a startup. See if that is anything other than a 1.

DCLVA is what your truck is using.
Not what is charging into your 12v battery.

Vehicle battery current of 1A looks like nothing but a trickle charge in your examples but I'm not familiar with your software.

 

[MakinDoForNow]

I don't drive much at night, but I did notice on one long 200 mile drive with headlamps on, that the battery charged to about 96%

I don't understand why, but when I replaced my flooded battery proactivly with an AGM H4; the normal 80% charge for the flooded batteru increased to 91% for the agm. No change other than the BCM reset and overnight relearn.

Someday I will try to increase the charge level via Forscan, but I just can seem to get "around tuit"!

The 91% is where the agm switched to float mode. Proof the battery learn procedure determined the agm and adjusted charge routine for it (ignoring the 80% setting that forescanners are changing).

 

[rslilly76]

Is vehicle battery current ever anything other than 1?

Look for it in the first couple of minutes after a startup. See if that is anything other than a 1.

DCLVA is what your truck is using.
Not what is charging into your 12v battery.

Vehicle battery current of 1A looks like nothing but a trickle charge in your examples but I'm not familiar with your software.

I'll have to watch that, there's a couple sensors that give that info, I'm learning at what to look at

 

[HeyBales]

I'll have to watch that, there's a couple sensors that give that info, I'm learning at what to look at

That other thread where you listed all the PIDs - did show a LVB Current, which may provide more figures than Vehicle Battery Current.
Or it's doing the same rounding to whole numbers the Forscan provides on 1 PID.
I found a 2nd Battery PID that gave the extra accuracy to see below 1A.

I'm wondering since you are already at 90% SOC, it's too late for this threads auto-ability to do it.
466 day old battery.
Maybe if you gave it one external charge - then tried the method.

In which case - it is operating the same as prior years.
Perhaps the limits are higher though.

 

[rslilly76]

That other thread where you listed all the PIDs - did show a LVB Current, which may provide more figures than Vehicle Battery Current.
Or it's doing the same rounding to whole numbers the Forscan provides on 1 PID.
I found a 2nd Battery PID that gave the extra accuracy to see below 1A.

I'm wondering since you are already at 90% SOC, it's too late for this threads auto-ability to do it.
466 day old battery.
Maybe if you gave it one external charge - then tried the method.

In which case - it is operating the same as prior years.
Perhaps the limits are higher though.

Those are all good questions! And thanks for the advice as I need it!

Just trying to put in extra data for 25 to see if it's different or if Ford actually fixed anything

 

[Darryl]

The 91% is where the agm switched to float mode. Proof the battery learn procedure determined the agm and adjusted charge routine for it (ignoring the 80% setting that forescanners are changing).

90% as measured by the vehicle is perfectly fine for battery longevity

 

[Mavster Mechanic]

90% as measured by the vehicle is perfectly fine for battery longevity

I'm wondering if Ford programmers are more clever than people give them credit for.

If the "set point" was either 80% or 90%, but they also knew headlamp use would top off above this; then batteries would get occasional top offs as people naturally occasionally drive with headlamps on.

Maybe all / most battery issues happen to people who rarely drive at night. And MAYBE Ford has learned not to assume all people do?

 

[HeyBales]

I'm wondering if Ford programmers are more clever than people give them credit for.

If the "set point" was either 80% or 90%, but they also knew headlamp use would top off above this; then batteries would get occasional top offs as people naturally occasionally drive with headlamps on.

Maybe all / most battery issues happen to people who rarely drive at night. And MAYBE Ford has learned not to assume all people do?

I'm convinced that the truck data readings from me and other geographical places like mine - are the reason why the 25/26 allow up to 15% in EV mode, instead of 10%.

Would have been nice if prior hybrid models had already given this info. Since I saw that tidbit on the 25's - I've noticed just how often I would benefit in my daily drives. Wouldn't be eeking out 40 mpg with lots of effort.

Or average drive times/frequency - gotta be known.

Even the driving in dark though.
Like a whole season's worth of more likely headlamp use.
Sadly - the battery is colder then too, so charging is backed down (from my logs).
And - did the battery reach the season in decent enough shape to be above whatever the lower limit is to allow higher charging?

Also the safety aspect of 12VB being in the cab basically - just in case a vent hose wasn't reattached on new battery.
Or wrong size battery put in - cheapest/smallest as some will do. Overcharging now?

I get the programming difficulty.
But your discovery shows they still have some fail safes in there that work just fine (if 100% SOC is decently accurate) that should prevent problems. So it seems the normal charging strategy could and has had some improvement.

 

[HeyBales]

The 91% is where the agm switched to float mode. Proof the battery learn procedure determined the agm and adjusted charge routine for it (ignoring the 80% setting that forescanners are changing).

Considering the Forscan sheets detailing things even say that 80% is a setting for EB's, which have 12VB specifics entered for them - that is a good example of the Relearn working right.

So maybe the differences David has seen as to the lower/upper limits of higher charging is based more on what it logged during Relearn, and no software update that effected the BCM/BMS system.
And my new warranty SLA back then was merely given 85% tops before discharge.

I still feel cheated!

3hr drive yesterday - got it from the 45% it had been hanging out at, up to 59%.
And it held at 57% this morning! 11.9 actually.
I'm sure the next Relearn is going to knock the SOC down though.

 

[MakinDoForNow]

I'm convinced that the truck data readings from me and other geographical places like mine - are the reason why the 25/26 allow up to 15% in EV mode, instead of 10%.

Would have been nice if prior hybrid models had already given this info. Since I saw that tidbit on the 25's - I've noticed just how often I would benefit in my daily drives. Wouldn't be eeking out 40 mpg with lots of effort.

Or average drive times/frequency - gotta be known.

Even the driving in dark though.
Like a whole season's worth of more likely headlamp use.
Sadly - the battery is colder then too, so charging is backed down (from my logs).
And - did the battery reach the season in decent enough shape to be above whatever the lower limit is to allow higher charging?

Also the safety aspect of 12VB being in the cab basically - just in case a vent hose wasn't reattached on new battery.
Or wrong size battery put in - cheapest/smallest as some will do. Overcharging now?

I get the programming difficulty.
But your discovery shows they still have some fail safes in there that work just fine (if 100% SOC is decently accurate) that should prevent problems. So it seems the normal charging strategy could and has had some improvement.

The reason for the 15% instead of the 10% lies in the improvements to the trans. Larger electric motors + , if I remember correctly, an additional tooth in gear set with a change in the final ratio. Programming will be adjusted when updates reference vin #'s.

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