HYBRID 12V Battery Mystery SOLVED

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I've never had an issue with interior lights or sleep mode, etc.
I was adamant about updating everything last year because I read on everything these trucks were doing. People gave me hell me wanting everything updated, but It's seemed to have helped.

Interesting. I noticed you have a '25, and OTA stands for over the air which yours has and mine does not. So not sure that will work for me, but I'll give it a try.

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[rslilly76]

Interesting. I noticed you have a '25, and OTA stands for over the air which yours has and mine does not. So not sure that will work for me, but I'll give it a try.

there's an OTA setting in your truck it just can't take all the OTA mine can. However, they should be able to tell you what your build requires updated to.

 

[HeyBales]

Depending on where you live, there are lemon laws. The dealer is on the hook if yours falls within the critiera.

Yes - but very unlikely to work on a "bad battery" wear item, due to undercharging, and the owner always drove in.
If Ford has buy backs associated with my comment - it's likely the intermittent drain issue, dead the next morning. Which probably solved the issue after days of keeping it looking for it - for then. Until it struck again - towed in again.

 

[MakinDoForNow]

Yes - but very unlikely to work on a "bad battery" wear item, due to undercharging, and the owner always drove in.
If Ford has buy backs associated with my comment - it's likely the intermittent drain issue, dead the next morning. Which probably solved the issue after days of keeping it looking for it - for then. Until it struck again - towed in again.

Takes fewer "tow-it-ins" than "drive-it-ins" to get serious "lets-fix-it" attention..

 

[Paulsr]

Same here. As high as 15.3 or 15.4 volts with a really undercharged battery. But 14's only with a charged or mostly charged one.

My headlight come on automatic still have problem

 

[samspritzer]

Yes - but very unlikely to work on a "bad battery" wear item, due to undercharging, and the owner always drove in.
If Ford has buy backs associated with my comment - it's likely the intermittent drain issue, dead the next morning. Which probably solved the issue after days of keeping it looking for it - for then. Until it struck again - towed in again.

NYS lemon law says four or more attempts to repair the car and problem continues to exist. And, car is out of service because its in the garage for an accumulated 30 days. I am not familiar with the other state's lemon laws.

 

[MakinDoForNow]

My headlight come on automatic still have problem

Automatic doesn't come on during daylight hours.

 

[HeyBales]

NYS lemon law says four or more attempts to repair the car and problem continues to exist. And, car is out of service because its in the garage for an accumulated 30 days. I am not familiar with the other state's lemon laws.

So to my point.
Bad batteries being replaced doesn't count. Car is maybe held overnight for a test - then a new battery if deemed good enough.
Getting a new battery every year under warranty isn't going to fall under that.

I think you missed the fact I had 2 paragraphs talking about different things in my post you initially quoted.

 

[HeyBales]

Takes fewer "tow-it-ins" than "drive-it-ins" to get serious "lets-fix-it" attention..

Especially when you use the free Ford assistance service for it each time.

 

[MakinDoForNow]

Especially when you use the free Ford assistance service for it each time.

Definitely when ford assistance service used whether for towing to dealer, or jump start, 3(?) or more will result in dealer being approved for overnight checking.

 

[Mavster Mechanic]

Pulled my trailer 4 hours yesterday.
Truck topped off the 12v battery and the trailer battery in about 1 hour.
Kept it at 14.0v and 100% charged for the remaining 3 hours.

This morning came out and SOC reading 96%. Normal (well, typical) 4% drop overnight. Bright sunny day. Left all lamps off.

Nice thing about ScanGaugeIII is you can set audible Hi/Low alarms for any parameter.

About 30 minutes into my normal commute (freeway speeds) ALARM! ALARM!

WTF???

12v battery had dropped to 11.5v and set off my audio alarm. Good thing I had it too. After so much towing and charging I was not paying much attention to the meter this morning.

Turned my parking lamps on.
Instantly 14.0v and 23 amps positive charging. With only 15 minutes left in my commute, charging tapered to 6 amps and voltage was 14.3v at the moment I turned the key off.

Theory:
I think the DC/DC converter is turning off completely in these cases.

Why else a fully charged (new 1 month old battery) would drop to 11.5v in 30 minutes? The (faulty?) SOC meter was still saying 92% so no attempt to charge was being made.

 

[johnDeere]

Yup, that’s the over 90% SOC charging voltage change over.
Fords setting for floating charge is programmed too low.

 

[Mavster Mechanic]

Dear Jim Farley,

 

[Mavster Mechanic]

Correct me if I'm wrong,

With a constant voltage (say 13.5, 14.0, 14.5 your pick) no "brains" are necessary.

The battery will take what it needs, reach homeostasis, and current will stop flowing into it.

I don't understand the need for all the voodoo witchcraft here.

 

[samspritzer]

Dear Jim Farley,

Dear Mr. Mavster,

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