Battery Management

[REV745DH24]

The article doesn’t mention 2024 Mustangs.

Yes but it shows lots of problems with batteries! Hope that has nothing to do with Mustang 2024!

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[DCS]

Yes but it shows lots of problems with batteries! Hope that has nothing to do with Mustang 2024!

That it does!

 

[roadpilot]

Ford will weigh in on this as fast as they did about the front wheel well issue. lol

There's nothing to weigh in on. @DCS's battery is measuring within normal resting battery voltage of 12.0V to 12.7V.

 

[DARK HP]

what size battery is in there a h6?

 

[Vapor Blue GT]

I don’t know what type of battery we have but anything under 12 volts and it’s considered dead and should be replaced. 12.6-12.8 not running and it’s fully charged with warm temps. If it’s colder like 30-40 degrees then it’ll read a little lower. Running your vehicle and the battery should be above 13.5 but no higher than 14.5 or it’s overcharging.

 

[DaddyTigggs]

I measured my battery voltage this morning with a good multimeter - 12.2 volts. I put the battery on my NOCO 5 Genius charger. 4 hours on the charger to get to "Green" - fully charged.

This afternoon I had to go on another short trip - about 8 miles round-trip. I watched the battery gauge the entire time.
Observations:
The gauge only moves in .5 volt increments - 12.5, 13.0, 13.5, etc.
I seemed to get up to 14.5 volts when DECELERATING! When accelerating or driving normally, it would flip between 12.5 & 13.0 volts.
I don't understand how this BMS (battery Management System) works.

I've had the car 9 days and just doing short trips around town. However, I put my charger on the battery as soon as I brought her home.

When you hooked up the charger, did you connect it directly to the battery or the jump points?

 

[Q6543]

Taking spot readings doesn’t work
I have a volt meter on mine built into my amplifier control and the car can be anywhere from 12.0V to 14.5V and everywhere in between at any random time.

 

[DCS]

When you hooked up the charger, did you connect it directly to the battery or the jump points?

Jump.

 

[sdsteele2]

The S650 has an AGM battery.

From what I understand, the nominal voltage for 100% charge is closer to 13v. AGM batteries can also take a slightly higher charge voltage ~14.5v with a float charge (battery tender) around 13.2-13.8v.

What I think we are seeing is the battery management system working to extend the life of the battery. On my other car, a Volvo that was designed when Ford owned them, the BMS works to keep the battery between 80-100%. By not constantly pushing for 100% the theory is it extends the life of the battery.

The BMS also adapts its charging strategy as the battery ages. That’s why it’s important to reset the battery life when you replace a battery. Also, if you manually charge the battery it’s important not to connect directly to the battery and instead connect after the BMS sensor

I’m assuming that the engineers factor in a known minimum acceptable state of charge to reliably start the car and program the BMS to work from that point.

For a daily driver that makes a reasonable amount of sense to me. I only ever use a manual charger when the car is going to sit for a while. Even though I store my car in a locked garage I also lock it to make sure it “goes to sleep” when I park it.

 

[DaddyTigggs]

Jump.

GREAT. Thank you.

 

[Skye]

@sdsteele2 ,

Good points and important distinctions.

- Ford has a plan as to how batteries will be managed

- There are chargers and there are tenders

While both can charge a battery, the tender "exercises" (my term). IMO, a charger is more blunt, something of a constant force on the unit. I understand chargers can back off once it senses its job is done.

I haven't studied the different product lines, but I'm sure with some vendors, you can both charge and tend.

 

[YamenGT650]

How come you guys are so worried about your voltage, and monitoring it?
Just drive the car every couple of days and it charges it self.
I don’t understand why the hassle of manually charging it and constantly monitoring….

 

[RLE55]

How come you guys are so worried about your voltage, and monitoring it?
Just drive the car every couple of days and it charges it self.
I don’t understand why the hassle of manually charging it and constantly monitoring….

Because not everybody drives it everyday and in some cases, weekly. Ours is a secondary vehicle-toy/fun thing if you will. Since Nov 1, it has been hibernating in my garage, so it goes on the trickle charger. Even after it comes out of hibernation, I keep it on the charger while in the garage, just to keep the battery at its peak.

 

[YamenGT650]

Because not everybody drives it everyday and in some cases, weekly. Ours is a secondary vehicle-toy/fun thing if you will. Since Nov 1, it has been hibernating in my garage, so it goes on the trickle charger. Even after it comes out of hibernation, I keep it on the charger while in the garage, just to keep the battery at its peak.

It’s my fun car as well which i use on weekends only, but are guys really that busy that you can’t drive it for once a week for half an hour or so!

A bit surprising not to drive it for 16-18 weeks, unless you’re like stuck in a snow packed neighborhood…

 

[DCS]

The S650 has an AGM battery.

From what I understand, the nominal voltage for 100% charge is closer to 13v. AGM batteries can also take a slightly higher charge voltage ~14.5v with a float charge (battery tender) around 13.2-13.8v.

What I think we are seeing is the battery management system working to extend the life of the battery. On my other car, a Volvo that was designed when Ford owned them, the BMS works to keep the battery between 80-100%. By not constantly pushing for 100% the theory is it extends the life of the battery.

The BMS also adapts its charging strategy as the battery ages. That’s why it’s important to reset the battery life when you replace a battery. Also, if you manually charge the battery it’s important not to connect directly to the battery and instead connect after the BMS sensor

I’m assuming that the engineers factor in a known minimum acceptable state of charge to reliably start the car and program the BMS to work from that point.

For a daily driver that makes a reasonable amount of sense to me. I only ever use a manual charger when the car is going to sit for a while. Even though I store my car in a locked garage I also lock it to make sure it “goes to sleep” when I park it.

What is the difference "electrically" if the car is locked vs. not locked?

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