stock battery 3.5 eco boost

[Jersey Jim]

It looks like an "equalize charge" that occurs every so many weeks on flooded batteries. What battery chemistry are they using? Forgive my ignorance, but I know nothing about the other trucks.

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[Gros Ventre]

In submerged cell batteries, a healthy battery will gas freely when fully charged (gassing begins 5-15% below full charge is reached, increasing slowly as full charge is reached). Better to do this at a lower rate charge since excessive gassing will slowly push off some active material from the plates. One way their life is extended is by designing in extra space below the plates for this material to accumulate (eg when enough of this stuff accumulates in the bottom it will short plates together kiling the battery). In an AGM type battery the plates are placed much closer together and have lesser capacity because of this spacing. This means they are capable of high bursts of power but have lesser overall capacity than submerged cell batteries. As I have learned about and thought about these batteries, I have concluded that the reason Ford sets the charging system up as it does (eg 12.6VDC & 80% charge) is to minimize, nearly to zero, the amount of gassing that occurs. This minimizes the amount of active material spalled off by charging. Why is that important? Since the plates are so much closer together and setup against the Glass Mats, this spalling off of material can harm the battery in a way, and sooner, that wouldn't occur in a submerged cell battery.

 

[Jersey Jim]

Good to know of the possible reason the "Target SOC" is set to 80% in my 2.7 eco. It DOES have an AGM battery, and that might explain why they set this so low.

Today I used an (external) inverter to charge one of my Pro series Stihl chainsaw batteries (largest capacity they make) with the ENGINE OFF. The alternator alone more than keeps up with this 26 amps draw nicely if idling. It brought my battery SOC from 80% down to 42% in the hour that it fully charged the saw battery. This 38% soc drop is why I am trying to take full advantage of the 70 Ah my truck battery "should" hold. I carry 3 saw batteries into the woods, but on a very rare occasion I need to charge one. After starting the truck, 135 amps was forced into that 70-Ah agm for several minutes, before it tapered off to under 100 amps, then slowly lowered to single digit amps. The battery fully recovered in 20 or so minutes. This seemed like an extremely high charge rate for an AGM battery.

Prior to this deeper than typical discharge today, my SOC never climbed above 81%. After this recharge, it climbed up to 88% before charge current tapered off to an amp or two. This got my hopes up, as 2 days prior I changed the BCM "target SOC" from 80 to 95%, but charging SOC still tapered off the charging current to 1 amp into the battery after reaching 80%. No change in charging at all.

Now here is an interesting part. I then reset the BCM, (as if installing a new battery) and the 88% SOC "IMMEDIATELY" changed to 80%! It's not like the battery was allowed time to discharge back down to 80%, but rather it seemed to have been "re-spanned/calibrated" to that 80%.

Am slowly trying to figure out the charging algorithm and how to change it, if even possible.

 

[Gros Ventre]

There are two ways to charge a lead acid battery: Constant voltage or constant current. In a submarine we use both. The first part of charging is constant current until a specified level of charge is reached (eg temperature-voltage-gassing) then shift to constant voltage. This is done to limit the gassing of the battery and thus the spalling off of active material from the plates. Under constant voltage the charging rate is an exponentially decreasing current. So it is continually dropping off in a curve. Initially that charge rate can be quite high but is high only for a short time and then drops to progressively lower rates. This is what you saw above. In other words the battery chemistry has a "voltage" that reflects its state of charge. The charging current is then proportional to the difference between the applied terminal voltage and this "state of charge voltage." The state of charge voltage rises quickly with high currents driving down that charging current. In other posts I've spoken of a wetting down charge. I'm thinking that a missing link in Ford's application of these AGM batteries is that their software, in limiting charge to 80% (12.6VDC), never applies this kind of initial, in service charge. As I've mentioned, when I put in that NAPA AGM Battery I did that wetting down charge without going through the F-150's electrical system. Took some 10 hours to get it charged up. Just a one time initial, in service charge. Then I hooked up the F-150's battery cables and off to the races. Haven't had a peep out of the truck's electrical system since. My take: Ensure you have an AGM specific charger; When you get a new battery (you'll probably swap it out where purchased) take the truck home; disconnect that battery from the truck's system; put it on a low rate charge (eg 1 or 2 amps); and let it go to completion. May take some 10 or so hours. Hook it back up in your truck and let the electrical system then run it. The Ford programming will run that battery back down from a no load terminal voltage of about 13.2vdc to their design point of about 12.6VDC. But my thinking says that with that wetting down charge applied, all of the battery's active material has now been properly activated and it will perform better.

 

[Jersey Jim]

Bill, Thanks for the insight to the effects of overcharging, spalling, etc. I've witnessed nothing "BUT" constant voltage mode on this vehicle. The charge current ALWAYS tapers off constantly. I believe the smart charging system could be configured to perform 3-stage charging, but Ford's priority seems to be getting their mpg computer to read as high as it can. Don't get me wrong, I love the fact that my daily reset of trip-2 shows a fuel economy of 24 or 25 mpg in economy mode, every day I commute 54 miles round trip. But I hate the fact that I'm carrying around a 3/4 full battery. Actually more like 25% because I don't consider the lowest 50% depth of discharge to be usable without the risk of sulphation. That why that last 15% or so is important to me.

My amazement is 2-fold..... 1, that I've seen as high as 15.00 VDC on the battery teminals while driving (Forscan Light) on a couple of occasions, and 2, that 135 amps and initially higher is allowed to be crammed down an AGM's throat! On my 2.5KW off-grid system using 8-D series AGM's, I'm using 8 valve regulated lead-acid (VRLA) batteries with valves that pop off at 2 psi if their charger profile is not configured correctly. That's one reason those agm's prohibit an "equalize-charge", which is usually on the order of 16 volts. But 15 in the truck is getting pretty darn close, and far exceeds my battery bank's max charge limit. BTW I use balancers on all 8 of those 8-D's, for 2 strings of 54V in parallel.

I wonder why when I change the truck's "targeted SOC" to 95%, I only see an increase in a few percent. And that may even be an unrelated coincidence, as the outside temperature has been at or just above freezing since making the change. Is there another module that grabs this value from the BCM, just once, or very infrequently? I'm beginning to think this higher than 80% value is interlocked by the "battery type" parameter. I'm tempted to switch the parameter to "flooded" briefly, just to see if a higher soc is futile with an agm. Any thoughts?

 

[RickBullotta]

Replace with Duralast H7 Platinum. Problem solved.

 

[Jersey Jim]

The battery type/model isn't the problem. In fact I'm not really having a problem. ANY battery I put in there won't be allowed to fill above 80% SOC. I'm having a problem with Ford's charging algorithm.

 

[Gros Ventre]

Bill, Thanks for the insight to the effects of overcharging, spalling, etc. I've witnessed nothing "BUT" constant voltage mode on this vehicle. The charge current ALWAYS tapers off constantly. I believe the smart charging system could be configured to perform 3-stage charging, but Ford's priority seems to be getting their mpg computer to read as high as it can. Don't get me wrong, I love the fact that my daily reset of trip-2 shows a fuel economy of 24 or 25 mpg in economy mode, every day I commute 54 miles round trip. But I hate the fact that I'm carrying around a 3/4 full battery. Actually more like 25% because I don't consider the lowest 50% depth of discharge to be usable without the risk of sulphation. That why that last 15% or so is important to me.

My amazement is 2-fold..... 1, that I've seen as high as 15.00 VDC on the battery teminals while driving (Forscan Light) on a couple of occasions, and 2, that 135 amps and initially higher is allowed to be crammed down an AGM's throat! On my 2.5KW off-grid system using 8-D series AGM's, I'm using 8 valve regulated lead-acid (VRLA) batteries with valves that pop off at 2 psi if their charger profile is not configured correctly. That's one reason those agm's prohibit an "equalize-charge", which is usually on the order of 16 volts. But 15 in the truck is getting pretty darn close, and far exceeds my battery bank's max charge limit. BTW I use balancers on all 8 of those 8-D's, for 2 strings of 54V in parallel.

I wonder why when I change the truck's "targeted SOC" to 95%, I only see an increase in a few percent. And that may even be an unrelated coincidence, as the outside temperature has been at or just above freezing since making the change. Is there another module that grabs this value from the BCM, just once, or very infrequently? I'm beginning to think this higher than 80% value is interlocked by the "battery type" parameter. I'm tempted to switch the parameter to "flooded" briefly, just to see if a higher soc is futile with an agm. Any thoughts?

They use constant voltage as it's far easier to set up software. In older electric systems they simply matched a temperature compensating circuit to the target alternator voltage. Note that max charging rate is temperature dependent. Wouldn't switch that mode from AGM. It appears that AGM batteries are subject to dmage from improper charging more so than flooded cells are. I think that 80% target voltage is set to minimize gassing since the plates are so tightly packed and the recombinant system in the battery could be overwhelmed. Note that if the case vents excess gas this is active fluid lost to the battery which can eventually reduce capacity.

 

[RickBullotta]

The battery type/model isn't the problem. In fact I'm not really having a problem. ANY battery I put in there won't be allowed to fill above 80% SOC. I'm having a problem with Ford's charging algorithm.

Anecdotally, every single person I've chatted with on this and the other F-150 forums who have replaced their OEM batteries with a quality aftermarket battery have eliminated all low voltage and sleep mode issues. Maybe it's just coincidence, but I very much doubt it.

 

[Jersey Jim]

Thanks Bill. That's why I said "Briefly" just to see if the newly entered soc value of 95% isn't being enabled/approached because agm type was provided/selected. At least I would know not to waste any more time pursuing the higher soc, if it were interlocked by battery type.

Each Stihl chainsaw battery I charge in the field, (just bought a 3rd) and is reason I want the fuller truck battery, costs as much as a Duralast H7 Platinum battery. So I don't really care if I take a year or two off of the service life. However, It would be nice if I could avoid the 42% depth-of-discharge that 1 saw battery drops me down to in the truck. So it's either the risk of overcharging a full battery, or the risk of sulphation from a deep DOD. I'll have to choose my evil. I just want results, convenience & practicality. "I never think of my wallet when working in the woods"!

And sure I could simply leave the engine idling to easily take care of the 26 amps, but I'm usually a half mile away from the truck on the 4-wheeler.

 

[Jersey Jim]

Like I said, I don't experience any of those problems. Not charging 54 miles a day. I just want to carry more Ah in the woods and hate to bring an unfilled truck battery.

 

[Gros Ventre]

Note that with a flooded cell battery that "gassing" is disassociated water. You add water to those cells over the life of the battery. The acid component remains in the battery cells although some acid is lost carried out with droplets that occassionally get out. But...!! with the AGM battery, it is sealed and you cannot add makeup water, so not overwhelming the recombinant capability of the battery is important. That catches the H2 & O2 that would have been vented by the flooded cell battery and return it to the cells as water.

 

[Calson]

The battery is a SLI type for starting, lights, and ignition (including electrical accessories). It has no value as a deep cycle battery as one finds in a RV or boat. It is designed to provide as high a cranking current as possible in a short period of time to start the engine. A deep cycle battery would suffer if used as a starter battery.

Software depends on good programming and having good algorithyms and making and validating the assumptions for the system. It is very rare for that to occur in the real world.

Some aspect of the battery management system is killing batteries and Ford management responded by increasing the "safety" margin for battery charging. It is a problem unique to Ford and one can only hope they fix the problem. If it is a deficiency in the truck hardware then a recall would be required and doubtful that Ford would incur this cost when they only need to pretend the problem is with the truck owners.

For my part I have bought a lithium-ion powered jump start battery pack and 20 foot long 2-gauge jumper cables which I now keep in the truck at all times. Having had my truck's battery dead twice in one week I cannot rely on it to start and need alternative options.

 

[Gros Ventre]

Thanks Bill. That's why I said "Briefly" just to see if the newly entered soc value of 95% isn't being enabled/approached because agm type was provided/selected. At least I would know not to waste any more time pursuing the higher soc, if it were interlocked by battery type.

Each Stihl chainsaw battery I charge in the field, (just bought a 3rd) and is reason I want the fuller truck battery, costs as much as a Duralast H7 Platinum battery. So I don't really care if I take a year or two off of the service life. However, It would be nice if I could avoid the 42% depth-of-discharge that 1 saw battery drops me down to in the truck. So it's either the risk of overcharging a full battery, or the risk of sulphation from a deep DOD. I'll have to choose my evil. I just want results, convenience & practicality. "I never think of my wallet when working in the woods"!

And sure I could simply leave the engine idling to easily take care of the 26 amps, but I'm usually a half mile away from the truck on the 4-wheeler.

A deep discharge doesn't necessarily cause sulfation. So long as you recharge reasonably quickly. The only things to think about is whether your battery is a deep discharge type. Plate design is different for starting batteries and deep discharge types. Specifically the deep discharge types have better spacing since the charge vs discharge products in the plates are physically different sizes and so flex the plates some if a significant range of charge discharge happens. An older flooded cell starting battery taken deeply into discharge and then recharged could only do that a few times before it would fail from this effect.

 

[Jersey Jim]

My point exactly Bill. These batteries don't exactly state "Deep Cycle" like most people use in their boats, but at least they have an "Ah" rating on them instead of reserve minutes (usually 23-25 amps test load). Although many mfgrs use a 100 hour rating that allows them to apply a minimal and impractical load just to advertise a higher Ah rating. Buyer beware.

Lately I've only used agm batteries in my boats, as they don't jostle around the sediment, or loose electrolyte on rough waves. The glass mat holds everything in place on high seas. It seems many battery mfgrs want to make a hybrid battery that isn't exactly one or the other, just a compromise of the two.

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