HYBRID 12V Battery Mystery SOLVED

[HeyBales]

Forscan Ez BCM 12V power outlet timeout setting can be changed from 4500seconds (75 minutes) default, to a shorter or longer interval. I once changed it to 14,400 seconds (4 hours), but seemed to cause a problem, so changed it back to 4,500 seconds. I also shortened it once to 5 minutes to prove it could, and it does. Now wondering if changing from 75 minutes to perhaps half that number, or something shorter than 75 minutes, would impact anything?

If you have a decent draw plugged into the power port - it would of course cut the length of the draw down to whatever.
That would impact battery life.
You aren't going to shorten other things though that are on timers, self-tests, ect.

I know ones changed the lights off timer via Forscan too.
But if you lock your vehicle - those are off quick anyway.
I guess if garaged and you just close door - some battery could be saved there with all the lights off quicker.

Those things could make the needed run-time with headlights or fan on spd 6 shorter to reach 100% - so might be beneficial for the short trip drivers.

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[MakinDoForNow]

Forscan Ez BCM 12V power outlet timeout setting can be changed from 4500seconds (75 minutes) default, to a shorter or longer interval. I once changed it to 14,400 seconds (4 hours), but seemed to cause a problem, so changed it back to 4,500 seconds. I also shortened it once to 5 minutes to prove it could, and it does. Now wondering if changing from 75 minutes to perhaps half that number, or something shorter than 75 minutes, would impact anything?

Someone posted years back about changing low time attempting to eliminate 12v draws, etc. as I remember they determined that setting it to 0 time kept it on permanently (until the 12v dropped to 10.6v +/- the "TRUE DEEP SLEEP REQUIRING JUMP START"). Seems like 5 or 10 seconds minimum time was required for computer to adequately start and stop the counter.

 

[Gullzway]

Some of you will laugh.
Some of you will cry.
Some of you will say "Holy Crap that's amazing!"
Some of you will say "Holy Crap that's dumb."

Here goes.

Fact: 2022 Hybrid (and others) actively drain a 12 volt battery to the computed 80% charge level.
Then do not try to add charge to the 12 volt battery until a computed 60% or lower charge is reached. God only knows why.
For 3.5 years my 12v battery has been "maintained" at about 60% charged. Always a resting voltage of 12.1 or 12.2.

Fact: running your headlamps will force the 12v battery to be 100% charged given enough time. (DRL will not do it. Parking Lamps only will do it.)

Fact: running your vents blower at speed 6 or 7 will force the 12v battery to be charged to 100% given enough time.

Fact: attaching a trailer, 4-pin or 7-pin will force charge the 12v battery to 100%.

Theory A: the truck needed to detect 12 volt demand, and above a certain wattage to trigger 12 volt charging.

Why would fan level 6 trigger battery recharging and fan level 5 would not? Why would full headlamps trigger battery recharging, but DRL would not?
Did the truck detect demand to run my camper fridge and coach battery?

I tested this last part. From Amazon I ordered a $10 LED brake light for the 2" hitch receiver with 4-pin connector.
Wow! The LED brake light pulling no power when not braking, and only 4 or 5 watts when braking DOES TRIGGER 12 volt battery recharging to 100%.
It's not the electrical demand that triggers recharging. It is simply thinking a trailer is there that triggers recharging.

Theory A shot down.

But this explains a lot.
This explains why some people have more 12v battery issues than others.

Those that drive at night a lot have more battery charging by happenstance.

Those that use fan speed 6 or 7 have more battery charging by happenstance.

Those who connect trailer wiring (and you don't even need a trailer!) have more battery charging.

Not a permanent fix. But a work around. Some of you may prefer running your headlamps more often over plugging into a home charger.

My 12v battery has been 100% for ten days in a row now. And is maintained at 12.7 or 12.8 volts. But I need to do one of the three "triggers" above or it rapidly starts to decline.

More to come...

Well I was going to try the brake light in the hitch attachment. Got it in today, but on the first drive I noticed I get the message " blind spot and cross traffic alert deactivated trailer attached."

That's not going to work for me. Is there a way to disable that? Or I guess I should say, enable that with the hitch light in.

 

[Mavster Mechanic]

Well I was going to try the brake light in the hitch attachment. Got it in today, but on the first drive I noticed I get the message " blind spot and cross traffic alert deactivated trailer attached."

That's not going to work for me. Is there a way to disable that? Or I guess I should say, enable that with the hitch light in.

In 2025+ yes.
22-24 no.

 

[Gullzway]

In 2025+ yes.
22-24 no.

Ah, guess I'll send that back to Amazon.

 

[Mavster Mechanic]

Ah, guess I'll send that back to Amazon.

Could use it "occasionally".

 

[KenE]

Run your headlamps every drive.

No one has yet confirmed if Forscan can set your headlamps to be on every drive automatically or not. I'll bet yes. I bet fleet / police vehicles want this set.

Yes you can with Forscan. You change it from the default "Auto" setting to "Last Known" position. I did this on my 25MY Hybrid. So if you turn Mav off with headlights in Headlight position, the switch will be in that position when you turn truck on. It's Fortran setting Ez BCM Autolock Initial Value, or 726-27-03 XXXX-XX3X-XXXX (7th hex # set to 3).

You need to stop basing things on voltage.

Voltage is not telling you anything once the key / truck is "on".

Only the "off" voltage is valid from the cigar lighter port, or the OBDII port.

Anytime the truck is "on" you are reading the DC/DC converter voltage.
Which masks the health of the 12v battery while driving.

I fully realize I'm reading the DC-DC converter voltage. I'm just submitting my Mav behavior vs some where this running voltage drops while ON, obviously indicating . And hopefully we all realize the charging mechanism is active when the truck is ON, Rotary Dial even in Park, Drive models optional. Thanks for your hard work on all our behalf. Very educational.

 

[KenE]

If you have a decent draw plugged into the power port - it would of course cut the length of the draw down to whatever.
That would impact battery life.
You aren't going to shorten other things though that are on timers, self-tests, ect.

I know ones changed the lights off timer via Forscan too.
But if you lock your vehicle - those are off quick anyway.
I guess if garaged and you just close door - some battery could be saved there with all the lights off quicker.

Those things could make the needed run-time with headlights or fan on spd 6 shorter to reach 100% - so might be beneficial for the short trip drivers.

Good point. My Mav gets parked in the pole barn, seldom, almost never locked. So if locking doors effectively shuts systems down quickly, does this short interval interfere with module updates, communicating with Ford Servers, etc?

 

[MakinDoForNow]

Good point. My Mav gets parked in the pole barn, seldom, almost never locked. So if locking doors effectively shuts systems down quickly, does this short interval interfere with module updates, communicating with Ford Servers, etc?

Also if you double lock (fob or key pad) the courtesy lights, dash delay, info screen, plus other things are turned off in 1 -2 seconds.

 

[KenE]

Also if you double lock (fob or key pad) the courtesy lights, dash delay, info screen, plus other things are turned off in 1 -2 seconds.

Manual states after neutral towing your Mav behind d a motorhome, DO NOT attempt to move or start it for 15 minutes. Just shift into Park, which exits Neutral Tow mode, exit vehicle. One time I needed to move it quickly, attempted to start quickly, had a screen full of errors. It started but was stuck in Park, unmovable to shift out of Park for several minutes. So there must be a need to give our babies a little time to settle in after turning off? They're a constant puzzle, mystery compared to all my previous vehicles.

 

[HeyBales]

Good point. My Mav gets parked in the pole barn, seldom, almost never locked. So if locking doors effectively shuts systems down quickly, does this short interval interfere with module updates, communicating with Ford Servers, etc?

No. For those that did it in the past - doesn't even shorten the lights on time.
Hence others do that setting.

 

[HeyBales]

Ah, guess I'll send that back to Amazon.

Just posted below - don't have to be driving.
May or may not be easier to use this method, once a week in the driveway while washing the truck, or cleaning it out.
Start it with trailer light in - do your thing for an hour - knowing it's charging high for that time.

Then again - an actual charger may be more effect at those times.

 

[MakinDoForNow]

Manual states after neutral towing your Mav behind d a motorhome, DO NOT attempt to move or start it for 15 minutes. Just shift into Park, which exits Neutral Tow mode, exit vehicle. One time I needed to move it quickly, attempted to start quickly, had a screen full of errors. It started but was stuck in Park, unmovable to shift out of Park for several minutes. So there must be a need to give our babies a little time to settle in after turning off? They're a constant puzzle, mystery compared to all my previous vehicles.

Double lock notifies computer you are through with truck for awhile and to advance shutdown of possible delay items. If you are in neutral tow and put in park then do not do anything else for 15 minutes. Double lock may or may not be ok during that time depending on how good the program was written. Be safe do not due anything for 15 minutes while computer restores non neutral tow status of all modules.

 

[dldjtad]

Watch this video.

12.x volts and discharging to 14.x volts and charging. All I did was manually turn on my headlamps.

Watch this video.

12.x volts and discharging to 14.x volts and charging. All I did was manually turn on my headlamps.

where did you get this from?

 

[Mavster Mechanic]

where did you get this from?

I own it. It's mine.

Plug in data reader.
ScanGauge III

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