Not starting after a good run

[MAGS1]

Alternator could be going bad too and not properly charging up the battery when driving. If the alternator can’t keep up, the battery will drain pretty quickly when the car is running

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[RTFM]

Great insights and informative list!

But I am not getting that one. How does that help? If anything, the security systems now starts drawing more power, no?

- Lock the car when not in use, even if in the garage

 

[Paddles]

Great insights and informative list!

But I am not getting that one. How does that help? If anything, the security systems now starts drawing more power, no?

If unlocked I believe the car's wireless system stays active, looking for a fob.

 

[JTM88]

My dash cam has a low voltage shutdown so it doesn't drain the battery, and I notice that the camera will turn off if I leave my car unlocked in the garage overnight, but if I lock it the camera stays on.

I assume that if the car is unlocked some systems in the car stay on and cause battery drain.

 

[Skye]

Great insights and informative list!

But I am not getting that one. How does that help? If anything, the security systems now starts drawing more power, no?

I've not confirmed the following via testing. It's a belief from others' posts over time. Next time I'm downloading documents from Ford, I'll search for this topic and see if I can confirm some things.

Power-wise, locking the car is telling it you're not coming back for a while. It's my understanding the car then goes into what I'll call "low-power mode". It does not enter its formal sleep routine, but it does shutdown or turn down unnecessary services to preserve power. The security system becomes active, yes; that will be drawing some power for the sensors. But other, non-essential services and some internal processes, it's my belief those will be turned down.

Skye's Deep Sleep Mode, the programmed mode by Ford, starts after two continuous weeks of inactivity. From Day 0 to 14, some services are active, Deep Sleep then turning the car down to its lowest power use point possible.

 

[Skye]

In the discussion with the OP yesterday, an Electric Power-Assisted Steering (EPAS) alarm and in-car charging system voltage of 13v were noted. Below are some excerpts from documents I have. They do not explain what the problem is or where to look. But they do explain the EPAS alarm and the voltage level at when most things go wonky.

414-01 Battery, Mounting and Cables Description and Operation

"The alternator is not dimensioned to support all loads in all situations. In some situations energy has to be drawn from the battery. These are mainly during:

engine idle
cold climate with a lot of electrical heating functions active
warm conditions with the engine cooling fan running
large transient loads (i.e. EPAS )"

^ This could explain the EPAS event

Ford and the S550 have a load shedding strategy, disabling certain features to prevent large battery drains which would compromise the battery and charging system. The following is one of the triggers used to determine when certain features are turned-off.

"Ignition on/engine off for > 30 minutes and
battery voltage <= to 12.8 Volts (Gasoline
engines)"

414-00 Charging System - General Information Description and Operation

"When any vehicle module is being programmed, connect an external battery charger to make sure the module programming is completed without interruption due to the load shedding feature becoming active. The external battery charger must maintain a system voltage above 13 volts. [Or if possible, perform the update with the vehicle running.] "

^ This is a limit for any of us: 13 volts. At or below this limit, systems throughout the vehicle could already be acting odd or begin shutting down.

Note: the Ford document and my comment relate to "system voltage", what's on the in-car display. Not necessarily voltage, as measured directly at the battery.

I was not aware of two points:

- That the alternator might not always be providing power at idle, or, all needed power at idle. This does make sense. Idle and low RPM, the alternator might not be spinning fast enough. Further, other documents state that, when the vehicle is started, the Powertrain Control Module (PCM) first checks and confirms the alternator is working correctly, then directs it to provide a determined output, which changes as-needed. Before then, the car is running from the battery. Momentary as it might be, it's of greater importance batteries be in good working order

- 13V seems to be the limit for systems, the floor when several functions risk being compromised or stop working all-together

In one hypothetical, a car with an already low battery (+) one with still more energy lost due to a recent engine start (+) and city driving involving idling, any modern vehicle could be quickly compromised.

I did some initial Googling on parasitic losses, internal processes and all that this morning. While I did find several interesting posts and comments, I did not find anything specific. I also didn't want to post something that might lead people astray. In summary, the Internet is littered with owners of modern vehicles complaining, concerned or chasing down parasitic losses.

Finally, I'm attaching a link to some general purpose reference documents, information that could increase awareness for the OP and those interested.

https://www.mustang6g.com/forums/threads/s550-electronic-modules-and-their-networks-a-primer.195769/

 

[G.T.]

Also OP, when it doesnt start, you hook up the jump pack, and it starts?

 

[petronix]

If it's not 14+ volts when running then it's not charging properly. I've had this happen in previous vehicles when the diodes in the alternator are failing.

Head to your favorite auto parts store and ask them to test your charging system. They should be able to produce a graph. If it is not a smooth line it is having charging issues

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