HYBRID 12V Battery Mystery SOLVED

[Falcon first]

Now we will be buying new headlights once a year instead of batteries.

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[okgaz]

Ok.
Do you have this light?
If you do, you have BLIS Blind Lane information system. That will be disabled if you plug in the trailer hitch brake light and you will get the dashboard warnings as shown in the above photos.

I believe I do.

A shame because that is a “good” solution but likely not worth disable safety features.

So OP is saying this truly forces the truck into charging appropriately? Any other downside other than the unintended safety features being disabled?

 

[Glen Baker LLC]

I believe I do.

A shame because that is a “good” solution but likely not worth disable safety features.

So OP is saying this truly forces the truck into charging appropriately? Any other downside other than the unintended safety features being disabled?

I have no idea.
@Mavster Mechanic has covered most of the pros and cons so far in this thread.

 

[Matso]

Very interesting insights and a logical explanation. I'll have to play around with it myself as my resting voltage is rarely above 11.8 v. But I would have to add, there is no free lunch. The energy to power that extra draw comes from the HVB. That in turn has to reduce efficiency. The reduction in mpg may be small but it's definitely not zero. Just spit-balling here but it may very well be the system was designed this way (as flawed as it is to us owners) to maximize efficiency and meet some goal at the expense of a suboptimal 12v SOC. Thoughts? from folks on here a lot smarter than me.

 

[Mavster Mechanic]

I believe I do.

A shame because that is a “good” solution but likely not worth disable safety features.

So OP is saying this truly forces the truck into charging appropriately? Any other downside other than the unintended safety features being disabled?

You can just run your headlights.
If you forget to turn them off in the daylight once in a while, I think you will be OK. They should turn off after a time limit. 10 min or maybe 15 minutes.

Or, look into if running headlamps with ignition is an option with Forscan. I bet it is. I bet some fleets and maybe some countries force headlamp on all the time which would make them turn off automatically too.

I just used the red lamp for a test to see if the camper was making the battery charge. Nope. Camper was not the reason. Same effect from a simple light.

 

[okgaz]

You can just run your headlights.
If you forget to turn them off in the daylight once in a while, I think you will be OK. They should turn off after a time limit. 10 min or maybe 15 minutes.

Or, look into if running headlamps with ignition is an option with Forscan. I bet it is. I bet some fleets and maybe some countries force headlamp on all the time which would make them turn off automatically too.

I just used the red lamp for a test to see if the camper was making the battery charge. Nope. Camper was not the reason. Same effect from a simple light.

Sorry. Not sure I understand.

I have automatic (day-time running) lights on all the time. Is that what you mean?

Or literally turn them “on” and leave that way? And they will stay on upon exit but shut off after a set time (10 - 15 minutes)?

And this does the same thing as the tailgate light “trick”?

 

[TheRealEman]

So the easiest thing for those of us who don’t tow would be turn the headlights on often?

 

[AVC]

Regarding LED life- that's an often cited false narrative.

LED may last 30,000 hours if you turn them on one time, and leave them on, at consistent voltage; in a stationary climate controlled laboratory.

One third of theoretical hours are realistic in real life. But still longer life than anything else. So 10,000 hours is still pretty good.

Yep, published LED lamp assembly life is usually a farce; given the cumulative derating of the LED's in harsh environments and high current designs, and the likelihood of individual LED or driver failure, I'd run these VERY spendy, basically unserviceable headlamps as little as possible, especially avoiding cooking them in daylight hours in the Summer, and hot climates. I've disabled DRL for this reason.

Would be interesting if some other accessory load (switched off when car is off) would trigger higher SOC.

 

[Glen Baker LLC]

Sorry. Not sure I understand.

I have automatic (day-time running) lights on all the time. Is that what you mean?

Or literally turn them “on” and leave that way? And they will stay on upon exit but shut off after a set time (10 - 15 minutes)?

And this does the same thing as the tailgate light “trick”?

Literally in @Mavster Mechanic First post of this thread it was was covered.
There was a question mark after his sentence so I'm guessing he does not know why the differences.

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

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...

 

[johnDeere]

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...

Nice write up, that is the same thing I found out last year when I was doing 12v battery testing.

But I can add to the info.
When the 12V battery SOC reaches 91% that is when it switches to 12.8 volts.
When you force the system to charge to 15.X volts:,
the voltage will stay at that voltage no matter how low the charging current goes to.
Very bad for a AGM battery.
If you battery is going bad, the SOC will be below the 91% so the charging system will still charge at 15.X volts.
Very bad for AGM battery.
My factory battery is going bad, after charging at 15.X volts for 4 hours, with a charging current down to .5 amps, my resting voltage was 12.6 volts. (bad).
My screen on my truck with car scanner shows 60% SOC so its reading close to the battery.
I can never get the SOC above 60% no matter how long I leave it charging, and reset and relearn.

You are correct where some owner were not seeing sleep mode because they were running the fan higher than 6 or had there head lights on.
But that will keep it in charging mode, but if you have a AGM battery, now you over charging the battery.
That's bad.
From what I have found,: there is charging voltage, (14.X to 15 .X).
And holding voltage of 12.8 volts. OK it starts off at discharging until the battery drops to 12.8V.

I have NOT seen a floating voltage of 13.X volts to maintain low charging current when the system thinks the battery is full.
If you have a good AGM battery, and the system thinks the SOC is above 91% it will change to 12.8 volts, and will not over charge the battery. (Good thing).
But its not floating voltage of 13.X volts, so now you may start to sulfate the battery.

From what I have found, (my truck does not have current draw after 30 minutes), so it good.
But after a 15 drive to work, with a EFB it can not recover fast enough to bring the SOC back up to where it started.
Maybe a AGM battery will recover faster, but since the faulty charging system, I do not want to test out a AGM battery.

Faulty charging system:
When the SOC reaches 91% it changes to 12.8 volts
You can force charging if you have the head light on or cabin fan above 6.
Forced charging will be 14.X to 15.X volts and will not change unless you intervene.
Forced charging can be up to 15.X volts and charging to below .5 amps.
There is no floating voltage to maintain the battery to full.
The system will not stop charging if SOC is below 91%, (even if its a false reading), no matter how low the charging current goes down too.

 

[okgaz]

Literally in @Mavster Mechanic First post of this thread it was was covered.

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

No need for all that.

I did go back through the thread and either missed it or it didn’t hit me.

You can also ignore a let someone else respond. Thought the point here was to help and discuss.

But okay. Thanks.

 

[johnDeere]

Literally in @Mavster Mechanic First post of this thread it was was covered.

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

From what I have found on my 23 mav hybrid, the only thing to trigger charging was to turn cabin fan above 5.
No other 12 battery loads would trigger charging.
lights, heated seat, heated steering wheel, wipers, windows would not trigger charging.

 

[Glen Baker LLC]

What was your beginning voltage?
What did the voltage go up to or down to when you MANUALLY TURN YOUR HEADLIGHTS ON?

 

[Mavster Mechanic]

So the easiest thing for those of us who don’t tow would be turn the headlights on often?

Yes.

This is the simplest solution.
If you drive at night more than an hour it's automatic for you.

If you only drive in the day, run headlamps in the day for an hour or as much as you can.

 

[Mavster Mechanic]

Nice write up, that is the same thing I found out last year when I was doing 12v battery testing.

But I can add to the info.
When the 12V battery SOC reaches 91% that is when it switches to 12.8 volts.
When you force the system to charge to 15.X volts:,
the voltage will stay at that voltage no matter how low the charging current goes to.
Very bad for a AGM battery.
If you battery is going bad, the SOC will be below the 91% so the charging system will still charge at 15.X volts.
Very bad for AGM battery.
My factory battery is going bad, after charging at 15.X volts for 4 hours, with a charging current down to .5 amps, my resting voltage was 12.6 volts. (bad).
My screen on my truck with car scanner shows 60% SOC so its reading close to the battery.
I can never get the SOC above 60% no matter how long I leave it charging, and reset and relearn.

You are correct where some owner were not seeing sleep mode because they were running the fan higher than 6 or had there head lights on.
But that will keep it in charging mode, but if you have a AGM battery, now you over charging the battery.
That's bad.
From what I have found,: there is charging voltage, (14.X to 15 .X).
And holding voltage of 12.8 volts. OK it starts off at discharging until the battery drops to 12.8V.

I have NOT seen a floating voltage of 13.X volts to maintain low charging current when the system thinks the battery is full.
If you have a good AGM battery, and the system thinks the SOC is above 91% it will change to 12.8 volts, and will not over charge the battery. (Good thing).
But its not floating voltage of 13.X volts, so now you may start to sulfate the battery.

From what I have found, (my truck does not have current draw after 30 minutes), so it good.
But after a 15 drive to work, with a EFB it can not recover fast enough to bring the SOC back up to where it started.
Maybe a AGM battery will recover faster, but since the faulty charging system, I do not want to test out a AGM battery.

Faulty charging system:
When the SOC reaches 91% it changes to 12.8 volts
You can force charging if you have the head light on or cabin fan above 6.
Forced charging will be 14.X to 15.X volts and will not change unless you intervene.
Forced charging can be up to 15.X volts and charging to below .5 amps.
There is no floating voltage to maintain the battery to full.
The system will not stop charging if SOC is below 91%, (even if its a false reading), no matter how low the charging current goes down too.

So far, running headlamps (or trailer lamps) 10 days in a row mine has never gone above 14.8 volts which should be safe for any battery.

In the past with a deeply discharged battery (lower than 60%) I did see 15.3 and 15.4 volts. But never in the past 10 days.

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