2021 Battery issues

[Big Dog Daddy]

After writing all of this, and looking at the pic's I posted of what I'm monitoring. I have a question, one of the pid's I'm monitoring is "A/S//S battery refresh cycle". From what I've read in the service manual this occurs occasionally, maybe once a month or on a longer trip to bring the battery back up to a full state of charge. Could there be a setting in forscan to change the frequency of "battery refresh cycle " or a way to decrease days between refresh?

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[Calson]

A problem with a battery can be from one that does not hold a charge or where there are parasitic draws while the engine is of or it can be a charging problem where the battery is not being properly charged by the alternator. Usually with a new battery the problem is with the charging system.

With my truck I will be monitoring the SOC over a period of several days and verifying that the alternator is actually taking the battery to 100% SOC.

 

[Snakebitten]

I think it's been fairly well established that the alternator is not going to charge the battery to 100% SOC regardless of how the truck is used.

You could drive nonstop for 24 hours and the battery management system will intentionally not allow the alternator to charge to 100% SOC.

In the old days if the crankshaft was turning and the belt was spinning the alternator, the alternator would be charging. But even back in the earlier 2000's the much less sophisticated battery management system on the F150 would stop the alternator from further output than the system warranted.

 

[Big Dog Daddy]

A problem with a battery can be from one that does not hold a charge or where there are parasitic draws while the engine is of or it can be a charging problem where the battery is not being properly charged by the alternator. Usually with a new battery the problem is with the charging system.

With my truck I will be monitoring the SOC over a period of several days and verifying that the alternator is actually taking the battery to 100% SOC.

Overcharging a AGM battery is going to reduce the life span of the battery, this is why ford has decided on 80% SOC. Many have bumped there setting to 90% or 95% but 100% will very quickly destroy the batteries cells thru off gasing.

SOC is a calculated value based on the battery manufacturers specification of amperage over time. You're trucks charging system checks this value thru the bms system thru an algorithm stored in the bcm based on the manufacturers specification table for the battery / the battery's number of days in service / and battery temperature. This is a perceived calculation that will change with any of these variables at any time.

Take a new AGM battery charge it at 67 degrees to 100% then put that battery in a freezer at 10 degrees for a couple of hours and test SOC again, you'll find it dropped to 90% or 85%

 

[Gros Ventre]

That drop in battery capacity/SOC is due to the temperature effects of the chemistry of the battery. Of course it dropped. That's why your truck, which only needs a hundred or so amps to start it needs an 800 amp battery... so that when you're in a Wyoming winter, it'll have enough reserve to start your truck...

 

[Big Dog Daddy]

That drop in battery capacity/SOC is due to the temperature effects of the chemistry of the battery. Of course it dropped. That's why your truck, which only needs a hundred or so amps to start it needs an 800 amp battery... so that when you're in a Wyoming winter, it'll have enough reserve to start your truck...

Agreed, my problem seems to be more to do with Ford's PCM/ BCM strategy for charging ice engine trucks. I have what people on the forum here are describing as a "short trip truck" in other words 5 days a week I drive 6 miles back and forth from work. Don't laugh! I see you're in Wyoming.

But anyway these short trips in colder weather seem to leave the truck in a net loss of charge each day, as it appears the strategy is to trickle charge the battery during operation. Good for the battery not so good for me. Beside the loss of charge from the keep alive for OTA and Fordpass functionality when parked. This slow degradation in charge eventually leads to the vehicles systems starting to shut down. First sign is loss of auto start stop, then interior lights disappear, then approach lights discontinue.
The only solutions I've found so far are to either drive further distance each day or throw a charger on it every few weeks.
I'm really hoping that Ford come out with a bcm update that addresses this issue with an adjusted charging strategy. Or I can find a setting in forscan that allows a bit more charge than what it's "currently" getting on short trips!

 

[Gros Ventre]

The "short trip" malady does slowly drain a battery. Batteries charge at an exponentially decreasing rate. So, if you don't drive for, say, an hour at least once a week, the battery will step down day-by-day...

 

[Calson]

The truck computer is guestimating the SOC based on the voltage of the battery which is not an accurate method but "good enough" for most purposes.

With older trucks a voltage regulator managed the charging of the battery from the alternator. I doubt this has changed with current trucks. We tend to believe a digital display even when we do not have a clue as to the underlying mechanics. If the reading shows more digits we assume it is therefore more accurate. Precision and accuracy are quite different but digital displays provide the impression that they are the same.

 

[Rm21f150]

The "short trip" malady does slowly drain a battery. Batteries charge at an exponentially decreasing rate. So, if you don't drive for, say, an hour at least once a week, the battery will step down day-by-day...

While I agree with this, the short trips are not the only issue. I can charge the batteries, drive a few hours, and when I start the next time, no auto start/stop. A couple of more stops and we go into deep sleep mode. Ford says the battery is good, charging properly, etc.
I will have it back at the dealer Wednesday for a parasitic draw test. 4th time in the shop in the past 10 months. Hopefully this will turn something up.

 

[Gros Ventre]

While I agree with this, the short trips are not the only issue. I can charge the batteries, drive a few hours, and when I start the next time, no auto start/stop. A couple of more stops and we go into deep sleep mode. Ford says the battery is good, charging properly, etc.
I will have it back at the dealer Wednesday for a parasitic draw test. 4th time in the shop in the past 10 months. Hopefully this will turn something up.

This is where the initial "Wetting down" charge may make a difference in setting up the battery internal chemistry... Since I did that, with a new NAPA AGM battery, I've had zero problems.

 

[Gros Ventre]

The truck computer is guestimating the SOC based on the voltage of the battery which is not an accurate method but "good enough" for most purposes.

With older trucks a voltage regulator managed the charging of the battery from the alternator. I doubt this has changed with current trucks. We tend to believe a digital display even when we do not have a clue as to the underlying mechanics. If the reading shows more digits we assume it is therefore more accurate. Precision and accuracy are quite different but digital displays provide the impression that they are the same.

Remember, the digital dashboard display shows you what it wants you know, not what things actually are.

 

[Rm21f150]

This is where the initial "Wetting down" charge may make a difference in setting up the battery internal chemistry... Since I did that, with a new NAPA AGM battery, I've had zero problems.

Did you do that yourself? What does the "wetting down" charge consist of?

 

[Gros Ventre]

Did you do that yourself? What does the "wetting down" charge consist of?

Spent a career in Nuclear Subs. Our main storage battery, a flooded cell lead acid type, is replaced every 3-5 years. We work them hard. On installing a new one, a low rate, wetting down charge is done right after fill and it takes awhile. What I have taken from that is when I get a new battery I ensure levels are equal (Can't do that on an AGM type) then put it on a low rate (usually 2 amp setting) and let it go to completion. That typically takes at least 10 hours even if it was initially nominally fully charged. Ford, your dealers, and even your store won't do this as it takes too much care & feeding. What such a low rate charge does is ensure all the reactive components are "set up" chemically so that all of those active materials are available for reacting (ie making electrons). In the old days of flooded cell batteries I would take out the battery each fall, clean the top and top up the cells with pure water. Then put it on a low rate charge for a day or until all cells were gassing freely. I've had batteries last 8 years that way. Well with an AGM you can't really do that... Looks like about all you can do is that initial charge. So what I do is, on buying a battery (or taking delivery of my new truck), I take it home and put it on that low rate charge. Takes about 10 hours at 2 amps. A higher rate is not necessarily useful as you want the chemistry to take its own sweet time and slowly react and convert to full up active stuff. Get a specific AGM charger.

 

[Henfield]

It can't help that so any trucks get parked for weeks on end waiting for parts. I think my truck got lucky. Within three weeks of ownership, it had already seen two 940mile drives plus a bunch of other drives totally 2347 miles. Then it pretty much slept the next month........ Its been in deep sleep a couple of times but started up right away on the fob.

 

[Calson]

FLAT and AGM batteries are intended for fast charging and fast current draw to start an engine. Below 50% SOC their useful life will drop significantly as they are not deep cycle batteries.

With the drop in battery charge state being observed it would take a 1/2 amp per hour drain to take the battery to below 30% SOC in a matter of days. The problem is determining what is using that amount of power.

I had a SUV that had a halogen interior light for the rear and one defective switch could turn the light on and by morning the battery was drained sufficiently to prevent starting the engine.

The inverter for the Pro Power unit if left on could result in this amount of draw but I have no way to troubleshoot this device. I have it set to be off but that does not insure the inverter is off.

Clearly we have bleeding edge technology in our trucks that is beyond the ability of the dealers, mechanics to troubleshoot.

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