Strange issues

[cprcubed]

It's been probably 2.5 years since Costco changed their battery warranty (which now blows). Too many people probably just brought their batteries back at 2 years, 11 months. I recently had to replace the two 65-series batteries in my Ford diesel. Walmart's were basically the same price and have a better warranty to boot. Plus, Walmarts are basically everywhere. Cheers!

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[sajohnson]

Nope. With the negative clamp to the fender bolt, the BMS is still in the circuit.

I just rewatched this video posted on the "Ford BMS Battery Monitoring System: How it Works, How to Properly Charge, How to Power Accessories" thread. It's queued to the relevant part.


I can see why people might be confused, because even the guy in the video -- who seems fairly knowledgeable, and is mostly advising correctly -- says, 'a body or engine ground should be used for the Neg(-) battery charger clamp so that the BMS is in the circuit and can keep track of the SOC.'

That is incorrect and contrary to the rest of what he says (about the 2021 truck) -- and what the the video shows, which is the negative charger cable attached to the side of the BMS opposite the battery terminal. That way the BMS can sense the current flow into the battery. He describes that here:


He says you don't *need* to find a body ground, when actually a body ground won't work (if the sensor is to 'see' the current). The negative clamp must be attached as shown in the video.

The older truck is different, and is perhaps the reason he misspoke. It has the Hall Effect sensor that encircles the Neg(-) battery cable. With that type, for the sensor to detect the current essentially any ground connection will do -- just not the battery negative terminal.

Both BMS sensors do the same thing -- measure current it and current out. The system in the older truck is simpler -- there is only one (1) cable connected to the battery negative.

The system the BS (and his 2021 truck) has incorporates two(2) paths to the battery negative: 1) the traditional connection to the body, and 2) through the BMS.

Your system of charging the battery *without* the BMS and then resetting it once it's at 100% SOC is fine. Either the neg(-) terminal or the fender ground will work -- they are both electrically the same. Any current flow through either connection will not be sensed by the BMS.

 

[BLUEOVALRACER]

Follow up on the battery issue. Checked the voltage this morning 18 hours after full charge and being driven yesterday.
Message again on the center screen and passenger door lock/unlock sensor not working.

DVOM read 12.1 volts, which for an AGM is approx. 50% SOC.

Hooked up my battery charger which showed 49% SOC.

Charged for 1 hour to 100% showing 12.64 volts.

Started vehicle and shut off, no message on screen and passenger door sensor worked.
Waited 15 minutes. Voltage now at 12.48 volts.

Message on center screen returned and the pass. door sensor not working again.

I don't want to reset the BMS yet because the battery is still under warranty and if the dealer hooks up Forscan the actual days of service won't show accurately from when it was installed.
Right or wrong?

I'm leaning toward a bad battery, but I guess it could be an excessive parasitic draw.

I'm going to check with my service advisor about the battery warranty.

With this being a Motorcraft( Chinese made) I don't know if the recall will come into play because it's a second battery.

Was the Hood Open when the Voltage went from 12.64 to 12.48 in 15 minutes?The Reason I Ask is the fans for the LED Headlights Stay on when the Hood is open which could have drained the Battery which makes no sense to me why those stay on when the Hood is Open?

 

[sajohnson]

Was the Hood Open when the Voltage went from 12.64 to 12.48 in 15 minutes?The Reason I Ask is the fans for the LED Headlights Stay on when the Hood is open which could have drained the Battery which makes no sense to me why those stay on when the Hood is Open?

I've wondered the same thing. The Badlands can be stone cold, not driven for days, and when the hood is unlatched and/or the driver's door is opened those headlight fans come on -- along with a lot of other stuff.

Those loads can pull a fully charged battery down to as low as ~12.1V. The drop is very fast.

 

[BLUEOVALRACER]

I've wondered the same thing. The Badlands can be stone cold, not driven for days, and when the hood id unlatched and/or the driver's door is opened those headlight fans come on -- along with a lot of other stuff.

Those loads can pull a fully charged battery down to as low as ~12.1V. The drop is very fast.

Makes no sense and i had the System Off To Save Battery come up again Today as well as many other Days.I put the little Viking Charger/Maintainer on it Today and Days in the past.I make sure the narrow flat cord from the charger is under the front of the hood so i can shut it when the charger is on it.I figure leaving the hood open with the Charger on it won't do anything to charge the battery if those fans are running for the headlights.

 

[sajohnson]

Makes no sense and i had the System Off To Save Battery come up again Today as well as many other Days.I put the little Viking Charger/Maintainer on it Today and Days in the past.I make sure the narrow flat cord from the charger is under the front of the hood so i can shut it when the charger is on it.I figure leaving the hood open with the Charger on it won't do anything to charge the battery if those fans are running for the headlights.

Our procedure is to unlatch the hood after returning home. Then I can check the battery anytime, without having anything turn on.

However, even if the hood is not unlatched when you go to check the battery and/or put a charger on it -- so the driver's door must be opened to unlatch and raise the hood -- the fans and everything else will turn off after a few minutes. You can leave the hood open if you want to.

WRT the 'System Off To Save Battery', two possibilities are:

1) If the Viking is connected directly to the battery terminals -- instead of the negative being clipped to the side of the BMS that's away from the neg(-) battery terminal (the metal on top of the BMS) -- the BMS won't sense the current flowing into the battery. The battery could be fully charged but because the BMS could not 'see' the charging current it doesn't realize that it's at 100% SOC.

It's a good idea to reset the BMS when the battery is at/near 100% SOC. Dude posted the procedure. It's in the owner's manual too (at least it's in ours).

That said, the system can eventually learn the battery's condition but IIRC the BS must be parked with the ignition off for ~8+ hours.

2) The battery is on it's way out.

Do you have a way to measure voltage?

I've been using a Battery Tender (BT) on ours and it has held up fine -- and it's the Chinese battery that is the primary subject of the recall. It's about 3 years old. I was going to see how long I could get it to last, but I'm more interested in getting a free AGM battery.

 

[BLUEOVALRACER]

Our procedure is to unlatch the hood after returning home. Then I can check the battery anytime, without having anything turn on.

However, even if the hood is not unlatched when you go to check the battery and/or put a charger on it -- so the driver's door must be opened to unlatch and raise the hood -- the fans and everything else will turn off after a few minutes. You can leave the hood open if you want to.

WRT the 'System Off To Save Battery', two possibilities are:

1) If the Viking is connected directly to the battery terminals -- instead of the negative being clipped to the side of the BMS that's away from the neg(-) battery terminal (the metal on top of the BMS) -- the BMS won't sense the current flowing into the battery. The battery could be fully charged but because the BMS could not 'see' the charging current it doesn't realize that it's at 100% SOC.

It's a good idea to reset the BMS when the battery is at/near 100% SOC. Dude posted the procedure. It's in the owner's manual too (at least it's in ours).

That said, the system can eventually learn the battery's condition but IIRC the BS must be parked with the ignition off for ~8+ hours.

2) The battery is on it's way out.

Do you have a way to measure voltage?

I've been using a Battery Tender (BT) on ours and it has held up fine -- and it's the Chinese battery that is the primary subject of the recall. It's about 3 years old. I was going to see how long I could get it to last, but I'm more interested in getting a free AGM battery.

To be Clear the times the System Off To Save Battery has come up on the screen the Battery Maintainer wasn't connected.

 

[sajohnson]

To be Clear the times the System Off To Save Battery has come up on the screen the Battery Maintainer wasn't connected.

That's what I was thinking you meant -- battery charged but Viking disconnected -- but you could see the 'System Off To Save Battery' message either way.

There are two situations:

1) The actual status of the battery -- voltage, SOC, etc.
2) What the BMS *thinks* the status is.

The Viking could have the battery fully charged, but the BMS might think it's low -- particularly if the charger had been connected to the battery terminals, not the other side of the BMS. The battery could be fully charged, 100% SOC, and floated at ~13.2V+ and the BMS would have no idea, and could generate the 'System Off To Save Battery' message.

 

[wireman]

Was the Hood Open when the Voltage went from 12.64 to 12.48 in 15 minutes?The Reason I Ask is the fans for the LED Headlights Stay on when the Hood is open which could have drained the Battery which makes no sense to me why those stay on when the Hood is Open?

I had the hood and doors closed because I waited overnight to take voltage readings, about 16-18 hours after the battery was fully charged.

 

[wireman]

FYI, the battery is made in South Korea and on Walmart's website the warranty is provided by Clarios.

 

[Dude]

And your reserve capacity is 140 minutes
(vs just 120 minutes on the Motorcraft EFB and Motorcraft AGM Batteries)

 

[Mark S.]

'a body or engine ground should be used for the Neg(-) battery charger clamp so that the BMS is in the circuit and can keep track of the SOC.'

I think you are misunderstanding what he's saying in the video. He's describing two different methods for two different types of sensors. The older style sensors are inline with the ground return cable. The newer style sensors are attached the battery's negative post. Look very carefully at the way he has the cable connected (photo below) and you'll see it's not connected directly to the battery's negative post. It's connected to the ground wire attached to the top of the sensor. Current from the charger will still go past the sensor before it gets to the battery.

Below is a photo of the connector on my car. The large wire going out the bottom of the photo goes to the body ground post on the fender. You can clearly see that it's connected to a tab on the side of the BMS sensor. If you clamped your charger's negative lead to the end of that wire where it connects to tab--which is essentially the same way as he does in the video--then all current going to the battery will go past the sensor.

That's what the presenter in the video is saying. You don't necessarily have to find a body ground point or connect to the engine block when recharging if you have a newer style sensor. You just have to be careful that you don't connect directly to the battery terminal to ensure charging current goes past the sensor.

 

[sajohnson]

I thought I'd try to summarize what I've posted so far:

In #47 I was commenting on the video when I said:

"I can see why people might be confused, because even the guy in the video -- who seems fairly knowledgeable, and is mostly advising correctly -- says, 'a body or engine ground should be used for the Neg(-) battery charger clamp so that the BMS is in the circuit and can keep track of the SOC.'

That is incorrect and contrary to the rest of what he says (about the 2021 truck) -- and what the the video shows, which is the negative charger cable attached to the side of the BMS opposite the battery terminal. That way the BMS can sense the current flow into the battery."

My guess is he was thinking about the older truck with the single negative connection (body > battery) and Hall effect sensor. What he said is correct for that setup.

1) It's fine to charge the battery the way it's been done for 100+ years -- connected directly to the battery terminals. The negative terminal or the fender grounding point can be used. It is electrically the same as the battery neg(-) and preferred for safety. After charging, the BMS can be reset via the factory procedure, posted by Duke, or allowing the BS to sit for at least 8 hours, posted by Dave.

2) Alternatively, you can follow the procedure shown the video. Positive to pos(+) battery terminal, negative to the metal on top of the BMS (demonstrated in the video). If it works as indicated, the BMS should know the correct SOC -- assuming it was synced correctly to begin with.

 

[BLUEOVALRACER]

I thought I'd try to summarize what I've posted so far:

In #47 I was commenting on the video when I said:

"I can see why people might be confused, because even the guy in the video -- who seems fairly knowledgeable, and is mostly advising correctly -- says, 'a body or engine ground should be used for the Neg(-) battery charger clamp so that the BMS is in the circuit and can keep track of the SOC.'

That is incorrect and contrary to the rest of what he says (about the 2021 truck) -- and what the the video shows, which is the negative charger cable attached to the side of the BMS opposite the battery terminal. That way the BMS can sense the current flow into the battery."

My guess is he was thinking about the older truck with the single negative connection (body > battery) and Hall effect sensor. What he said is correct for that setup.

1) It's fine to charge the battery the way it's been done for 100+ years -- connected directly to the battery terminals. The negative terminal or the fender grounding point can be used. It is electrically the same as the battery neg(-) and preferred for safety. After charging, the BMS can be reset via the factory procedure, posted by Duke, or allowing the BS to sit for at least 8 hours, posted by Dave.

2) Alternatively, you can follow the procedure shown the video. Positive to pos(+) battery terminal, negative to the metal on top of the BMS (demonstrated in the video). If it works as indicated, the BMS should know the correct SOC -- assuming it was synced correctly to begin with.

Yesterday i hooked the charger maintainer up for almost 5 hours before i went to work and this time i hooked the negative up to the body ground over towards the fender and the positive to the battery. When i hooked the charger up it was showing 12.1 volts on the charger and when i took it off almost 5 hours later it was showing 11.7 volts. FWIW the System Off To Save Battery came up when i started it before and after i put the charger on it .When i drove to work and shut it off and restarted it no More System Off To Save Battery after 15 minutes of driving. FWIW the other times i put the maintainer/charger on it i hooked the cables up to the Negative and Positive posts on the battery.

 

[sajohnson]

Yesterday i hooked the charger maintainer up for almost 5 hours before i went to work and this time i hooked the negative up to the body ground over towards the fender and the positive to the battery. When i hooked the charger up it was showing 12.1 volts on the charger and when i took it off almost 5 hours later it was showing 11.7 volts. FWIW the System Off To Save Battery came up when i started it before and after i put the charger on it .When i drove to work and shut it off and restarted it no More System Off To Save Battery after 15 minutes of driving. FWIW the other times i put the maintainer/charger on it i hooked the cables up to the Negative and Positive posts on the battery.

Offhand, I'm not sure what to say about that.

How much current does the charger maintainer put out in bulk charge mode? If it's more of a maintainer (like the Battery Tenders I use) and the battery has a low SOC, 5 hours might not be enough.

WRT the charging using the fender grounding point and the voltage dropping from 12.1V to 11.7 -- perhaps there was not a good connection at the fender ground? Is it bare metal?

FWIW, I use the battery neg(-) terminal, because it's easier and a clean connection. I'm typically just maintaining/floating an already charged battery, and the BT (Battery Tender) doesn't arc -- so there's no need to use the fender connection (it should be used for jump starts though). Our Badlands sits for days at a time so the system learns the SOC without doing a BMS reset.

No problems in 3 years.

Other possibilities are:

1) Faulty battery
2) Defective charger (not charging, meter incorrect)
3) Significant parasitic load

As for the "System Off To Save Battery", the battery really could be low, OR the BMS 'thinks' it's low (but it's not) and needs to be synchronized.

You might consider having the battery tested.

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