Deep Sleep FIX - Maverick Hybrid 12V battery - One Year Update

[HeyBales]

Is setting the SOC to 100 necessary or could I just get by with replacing it with an AGM?

Not a valid figure in Ford's SOC scale.
85% is max fully charged battery.
80% is change to float charge.
That's about 94% charged - so correct theory.
Bad implementation.

If the problem is the sensors aren't accurate, on which that SOC% is based - then setting to 84% might be useful. It'll wait until then for float charge, but maybe in reality it's a tad lower and still safe.
After a long drive - open up battery compartment and smell for that battery odor - just in case.

Then again if your battery is old, even after a recharge and BMS Relearn locked overnight - it may think (and be correct) that it can't take a full charge anymore, so it may not attempt up to the 84% anymore with the change. Mine did that, from my comment right above your post.

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[Egz]

Its original from early 2022. Its just been deep sleeping more often lately. Today, I got the notification after an hour drive and parking. Was just hoping a battery replacement was all I needed, or if I had to hook up Forscan.

 

[HeyBales]

Its original from early 2022. Its just been deep sleeping more often lately. Today, I got the notification after an hour drive and parking. Was just hoping a battery replacement was all I needed, or if I had to hook up Forscan.

In that case - you are probably just reaching the new normal EOL time for smallish batteries in vehicles that have micro-drains.

Go for AGM battery from location of your choosing (especially if DIY and warranty may matter, do BMS reset/Relearn then), might help make it even longer.

Great to hear about someone not having issues until now.
Curious, what mileage on it?
Was that from driving regular daily/almost or long infrequent trips?

 

[Egz]

Great to hear about someone not having issues until now.
Curious, what mileage on it?
Was that from driving regular daily/almost or long infrequent trips?

79k. Fairly regular daily use, commute is 1 hour each way. Longest it would go without driving is an occasional weekend.

 

[Darryl]

Even those reporting no Deep Sleep Mode on their old batteries - which are few and far between most posts - show low voltage on battery when measured, no where near what would be considered fully charged 12.6-.7 V on FLA. They just seem to maintain above the cutoff for DSM. (until winter!)
Obviously there could be a whole group with no battery problems that do indeed have fully charged batteries. For some reason I'm doubtful.

I tried testing that BMS reset last year after 2 months of use from new to me (but older battery), after reading about the battery issues and seeing my low SOC%. Did a full recharge, BMS reset, and BMS Relearn. Did it later after summer too, throwing a drive in there before the park. Didn't help - never tried to charge to 85% full charge.
https://www.mavericktruckclub.com/forum/threads/hybrid-12v-battery-charging.47437/post-874151

I could see that reset possibly helping if system stats are showing more charging than discharging has occurred - in which case the BMS might be holding back high charges. Back then mine was always more discharge than charge. New battery now - tad more charge Ah than discharge until this week - discharge total went up 1 before the charge total did. And battery has been dropping in V & SOC the whole time since install. So obviously not charging more than discharging - inaccurate readings/tracking algorithm.

There is a system PID for Quiescent Battery Current Low Range mA - for that time after the 75 min max going to sleep.
Which makes sense, there is also a PID for Cumulative Discharge Ah in Sleep Mode. So it tracks it.

That QST reading appears to be avg thru the entire time, not peak. Supposed to be 25-50 mA per service manual. Infrequently mine is down around the 25 mark. Most often above the 50 mark, with some shorter times around 85.
If the system never went into sleep mode, you don't get a new value, it shows the prior one.
Sometimes it must sleep after 20-30 min, as I will get a new value - those are usually the high ones - so indeed something isn't going to sleep fully when the system starts logging sleep mode.

But doing the math - if one can trust those readings - even 90 mA avg for say an entire day sitting, instead of expected say 25 mA on low end - 65 extra mA avg ain't much extra. Not even on say the 45 Ah smaller OEM battery.

So is the draw during the potential 75 min after each drive really that bad?
Funny it used to be frequent short trips was bad for battery due to crank use and lack of time to recharge, now with barely any "crank" power it's because of extra opportunities for high draw after each trip. Or is it?

So my last PID screen shot is showing discharging of 2 Ah during sleeping time, 4 Ah during system off (sadly it rounds to whole numbers).
So if the 2 Ah is comprised of somewhere between 25-85 mA avg usage for the probably 22 hrs of sleep time (1hr driving, 1 hr going to sleep), then the going to sleep time is double that draw for 1 hr of time.
But that means 50-170 mA avg for 1 hr - that still shouldn't be bad enough to be considered a deep draw.

To your point about charging from 50 to 85% SOC being hard on battery - well, at least the BMS system seems to give up much faster than that! - at least when it thinks (and there was) a bad battery. Amp levels drop quickly to unsustainable levels - seems the goal changes to 70%, then 57%, then it's dying. Got to point that anything more than a 10 min drive wasn't useful anymore as charge Amps were between 0 & 1 halfway thru.

I appreciate your reminders that many may not have been familiar with on older cars, get close to draining the battery & you aren't making it up quickly - and you did hurt the battery most likely.
And that's why I'm wondering if Ford is getting the proper perspective on this.
If they keep thinking it's only bad batteries from manufacturing (due to warranty replacements), or parasitic draws that kill a few - then they'll never think there is a need to examine the idea that undercharging created bad batteries to die, or made it easier for an infrequent parasitic draw to kill and ruin a battery earlier.
Then again - it's been said before, perhaps they know, and the slight undercharging provides an extra 1-2 mpg in the test loop drives for official reporting.
[/QUOTE
It IS a parasitic drain. How do we know? We'll install a new battery. FULLY charge it, drive the truck, let it sit a day or two. And it might be DEAD. Ford had had us to leave the battery connected overnight and compare the charge level vs the level when it sits overnight disconnected. Ford had an issue with some of their vehicles not charging the battery fully. They had us to fully charge and test the battery. Replace if necessary, then reprogram the software. So I'm sure they have checked for that in this case since it was a problem in some of their other vehicles.

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