Auto Stop/Start Not Working

[grumpyunk]

At the dealer, the tech used a tester to determine battery condition. All A-OK number 1... 12.47V 923 CCA vs 700 rated. But start-stop doesn't think that's true, or something, so it is disabled.
Made an appt for about 1 month out( yup, theyz backed up apparently due to not having enough techs or enough bays or ???) to have it checked.
At home, connected a 'smart' battery charger. It was pumping in @8.6A, indicating, at least to me, that the battery was not fully charged.
Given the numbers in multiple charts indicating a 12V battery@12V is about 50% discharged... I have to agree with the charger.
I am getting the impression the charging system is NOT designed to fully charge, all the way to the gills, the normal 12v battery. As long as it can meet current (no pun intended) demand, the charging system will do just that, and maybe throw a bone to the battery now and again.
When I take it for a ride next, I bet a nickel that the start-stop works perfectly.
What does all the above mean? If your battery is not fully charged, the charging system will not make much of an attempt to bring it back to full charge. OR. The battery testing equipment used at my local dealer is not really testing the battery, but what the battery COULD produce should it be fully charged.
We shall see if the battery maintains voltage above the 12.1-12.3 level(max noted to date prior to yesterday's charge) with whatever the charging system produces. If it drops, and the s-s does not work, then I will not cancel the April appointment. (yeah, drop off and hope they fix it within a few days.... )
tom

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[taralon]

If it is 12.47 volts after driving a while, then that battery isn't charging right, and probably should be replaced, 12.4 resting after a drive is an indication the battery is around 60% charge which is poor. At this voltage the batteries are being charged at bulk charge rates which would push them towards 95% charge very quickly. The fact that the at home charger was pushing that high an amperage also points to a battery that won't take full charge as it was still in bulk.

Start/stop systems are programmed not to run if the battery is not close to fully charged (90+%). This is so they don't run a poorly charging battery (or a system where the alternator isn't working correctly) flat, and strand you at a stop light.

 

[NeedForSteve]

After a 30-45 minute drive, a voltmeter directly on the battery posts within a couple minutes of shutting the car off should show 12.8 volts or so, and (if healthy) the battery should settle down to 12.6 or so after about 15 minutes. If it's not doing that, or very close, something is wrong. Also, you can ask for a printout from the Rotunda battery tester the dealer should be using. If they're honestly hooking the battery up to any sort of tester for Ford Warranty purposes, it should be a Ford/Rotunda tester capable of printing results. That will show if the tech is setting the tester properly.

 

[grumpyunk]

Checked with Fluke next AM, and battery was at 12.5v. When I disconnected the charger the previous night(11PM), it indicated over 13v when I touched the terminals to the battery posts.
So the charge drooped from 13.4-ish(memory) to 12.5 overnight.
Given my limited knowledge of ECM strategy to charge the battery 'slowly' when driving rather than running it up to a full charge immediately, I have no idea how to interpret the above voltages.
I *think* the battery has a problem, and will not keep a charge... but it has started the engine every time. I do not have a clue as to how to test the battery or the charging system. One tech informed me that a fully charged 12v battery would read right around 12v... (I did not disagree as I am a know-nothing customer) No point in arguing.
My bet is the voltage will be below 12.5 this AM, ~36 hours after disconnecting the charger.
tom

 

[NeedForSteve]

Able to have someone start the truck while you hold the meter on the battery to see how low it sags under starter load?

 

[grumpyunk]

After a 30-45 minute drive, a voltmeter directly on the battery posts within a couple minutes of shutting the car off should show 12.8 volts or so, and (if healthy) the battery should settle down to 12.6 or so after about 15 minutes. If it's not doing that, or very close, something is wrong. Also, you can ask for a printout from the Rotunda battery tester the dealer should be using. If they're honestly hooking the battery up to any sort of tester for Ford Warranty purposes, it should be a Ford/Rotunda tester capable of printing results. That will show if the tech is setting the tester properly.

The battery was tested at the dealer, immediately after a 10 mile drive down the freeway. Voltage was 12.47 per the printout, CCA was 923 indicated vs the 700 entered by the tech into the test equipment. Techs indicated battery was fine, and there was another problem.
The post I was writing when yours posted has a bit more.
I am getting less sure what is happening, but think the battery does not hold nor accept a full volt charge.
tom

 

[grumpyunk]

Able to have someone start the truck while you hold the meter on the battery to see how low it sags under starter load?

Maybe get spouse to do that. Should rem,ain above 10v as I understand if the battery capacity is not less than normal.
tom

 

[NeedForSteve]

Gotcha. That voltage seems low fresh off the road, and the entered vs. actual CCA reading makes me question the setup of the tester. 10V is just about right for starter draw. I'd like to see 10.5 on a battery this new but that's just me.

Did they mention whether or not they scanned for any codes while they had it in? I'd wonder about possible BCM/BMS codes. I can't look up current TSB's anymore as my FMCDealer stuff has finally been turned off.

 

[Johnkn]

If I had an ongoing issue like this and the dealer did not install a new battery, I would go and purchase a quality replacement battery and install it in order to take that out of the equation. Good luck.....


.

 

[grumpyunk]

Just checked resting voltage - 12.6 and climbed slowly to 12.69. That about 36 hours after full charge to 13.4.

 

[grumpyunk]

Gotcha. That voltage seems low fresh off the road, and the entered vs. actual CCA reading makes me question the setup of the tester. 10V is just about right for starter draw. I'd like to see 10.5 on a battery this new but that's just me.

Did they mention whether or not they scanned for any codes while they had it in? I'd wonder about possible BCM/BMS codes. I can't look up current TSB's anymore as my FMCDealer stuff has finally been turned off.

I think the voltage was low after the short drive as it had been reading just above 12v when parked for a few days. I thought a 12.1v battery was about 50% charged given charts on the net. Tech did not agree, but said bring it in.(fastlane). They checked as above, batt up to 12.47 per test after 10 minute-ish drive.
I looked for CCA on tags, and did not find. Techs were talking, and I stayed back to allow them freedom from helicopter-man. Dunno if 700 is correct, but the tester indicated good & 923CCA capacity.
Getting 12.69 now, day and a half after fully charging, and I am becoming more and more confused. The charging system indicates 14.1-14.2 when at idle (cheap meter stuck in power port), and I cannot/won't look when driving as it's down low. But batt voltage has always stayed low since(until not) I noted the start-stop was dysfunctional.
I will monitor and do the voltage while starting test.
tom

 

[NeedForSteve]

You're generally correct about the 12.1v/50% state of charge. As others have said, you've done as much as you should be expected to with a new car.

If the issue persists, when you take it back insist it be diagnosed since the issue is recurring. If you have a charging issue, it should be easy to find but it's going to be over a lube tech's head.

 

[Ford Motor Company]

Checked with Fluke next AM, and battery was at 12.5v. When I disconnected the charger the previous night(11PM), it indicated over 13v when I touched the terminals to the battery posts.
So the charge drooped from 13.4-ish(memory) to 12.5 overnight.
Given my limited knowledge of ECM strategy to charge the battery 'slowly' when driving rather than running it up to a full charge immediately, I have no idea how to interpret the above voltages.
I *think* the battery has a problem, and will not keep a charge... but it has started the engine every time. I do not have a clue as to how to test the battery or the charging system. One tech informed me that a fully charged 12v battery would read right around 12v... (I did not disagree as I am a know-nothing customer) No point in arguing.
My bet is the voltage will be below 12.5 this AM, ~36 hours after disconnecting the charger.
tom

Hi there! Can you send us a PM with your VIN and Ford dealership information? I’d be happy to look into this Maverick concern on my end.

 

[LIL’ Buddy]

Well… I always shut this off now when I get in first thing… but today on the way home from work… scared the crap out of me! Loud alert and red warning screen! 12v charging system service now type message. It would go off finally and then battery light would go off, then come on again. It did this over five or six different times while driving home on 80/94 from work speeds of 65-80mph. Whether nothing on or all systems on. Scary! I think it has a lot to do with this: truck built and Sat from 10/15/21 until it was delivered 12/15/21 then I bought it 12/21/21… is it because the batteries might not be that great and being new and not driven or turned on it caused them to fail? Maybe the charging system sucks and affects the battery? Maybe their is parasitic drains? Anyways…. Hope a system check and battery maybe is all in order?

 

[LeersMav]

Auto stop/start must meet a few different conditions to operate.

• engine at operating temperature
• battery voltage low/ electrical load under 10w
• ambient temperature
• cabin temperature
• rear defrost not selected
• high heat not requested
• max cool not requested
• no trailer connector attached

@oreomuffin Checking the Owner's Manual pages 168-170 provides information (like that above) on Auto Start/Stop and why it will not operate with some threads confirming what is said. Just passing along info.

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