12V battery State of Change (SOC)

[wrgrimes]

At 5mo, I had a “Full Accessory mode” lock out. Truck would not start. 12V battery was too depleted to test- warranty replaced at dealer.
Bought OBD MX+
2 days ago I had “Deep Sleep” notice when I tried remote start.
Yesterday, I thought to check SOC- 80%. A little ICE idle bumped to 81%. Errands to include 40mi interstate up to 94%.
I drive almost daily, short errands and 2mi commute 3x/wk.
On work days, I eat lunch in the truck, idling.
1. What is the expected range for SOC?
2. At what SOC is Deep Sleep imposed?
3. Concerned that frequent, but brief driving plus idle can deplete battery
4. I thought Li battery replenished 12V
5. I am trying to get better about restoring Li SOC with active idle.

Comment and education are appreciated.

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[Snakebitten]

When you say Li, you mean the little 12V auxiliary battery under the seat?

Just clarifying you don't mean the "Li" High Voltage battery.

I'm stunned you got a 94% SOC from the 12V battery unless you charged it externally with a battery charger. I've never seen the battery management system even attempt to give the 12V battery enough charging current to get to that SOC. However, you DO have a new battery and mine is ~420 days old.

And the one issue that the OBD monitoring can't address is what's going on with the 12V battery when the truck isn't in accessory mode or running mode.

Anyways, it's good to see you take battery monitoring into your own hands!

 

[wrgrimes]

When you say Li, you mean the little 12V auxiliary battery under the seat?

Just clarifying you don't mean the "Li" High Voltage battery.

I'm stunned you got a 94% SOC from the 12V battery unless you charged it externally with a battery charger. I've never seen the battery management system even attempt to give the 12V battery enough charging current to get to that SOC. However, you DO have a new battery and mine is ~420 days old.

And the one issue that the OBD monitoring can't address is what's going on with the 12V battery when the truck isn't in accessory mode or running mode.

Anyways, it's good to see you take battery monitoring into your own hands!

Thanks
My ignorance is shameless
I forgot that there are 3 batteries- I was referring to the large hybrid battery that ranges~40-60%.
I have no clue what the battery under the seat does. Can it be monitored?
What SOC should I look for with the main 12V?
Does the hybrid battery replenish the 12V? I believe you have commented that it can jumpstart the 12V.
I need to adhere to your advice of leaving the hybrid battery well charged before shutting down.

 

[Gros Ventre]

The little battery under the back seat is a "Keep Alive" battery for certain circuits/memory components. It will keep those things going when you start the engine either by the geared starter or the belt starter. This is needed because when you start off the 12VDC battery its voltage dips quite a bit, particularly in wintertime. The Li battery can charge the 12VDC battery thru a DC to DC converter. The system is set to maintain the 12VDC battery at 12.6VDC, I believe because the AGM (Absorbed Glass Mat) is especially sensitive to over charging, so they target it at about 80% charge.

 

[wrgrimes]

The little battery under the back seat is a "Keep Alive" battery for certain circuits/memory components. It will keep those things going when you start the engine either by the geared starter or the belt starter. This is needed because when you start off the 12VDC battery its voltage dips quite a bit, particularly in wintertime. The Li battery can charge the 12VDC battery thru a DC to DC converter. The system is set to maintain the 12VDC battery at 12.6VDC, I believe because the AGM (Absorbed Glass Mat) is especially sensitive to over charging, so they target it at about 80% charge.

Thanks
Just got back from 150mi interstate
85% charge.
I think AGM batteries are not happy below 50%; correct?

 

[Gros Ventre]

All lead acid batteries do not like being low on charge for an extended time. Can lead to various things that shorten life. A discharge down and right back up is not a problem. My homework says these AGM batteries are particularly subject to overcharging damage. A regular flooded cell battery is not hurt by a long term low amp charging. I've had them last 8 years. I'd once a year pull it out of the truck, do a cleaning of the top, and then put it on a long term (>day) 2 amp charge (which would taper down to a really low rate). I always used pure water makeup... Well you can't add makeup to an AGM. I'll still pull it out once a year and give it a low rate long term charge. With Submarine batteries we called it an equalizer charge. Lead acid batteries get sulfate compounds that plate out and equalizer charging reduces this. But the fact of a 12.6VDC setting (eg 80%) in the software of the F-150 is done, as best I can determine, because of an AGM having a greater sensitivity to over charging.

 

[PB2021]

I put our 21 PB on charger overnight every so often. Even after full charge connected behind the BMS the highest I’ve seen through MX+ is 93% SOC. From monitoring charging when driving there is very low current coming to the 12v system when SOC is high. Normally I’m not seeing much current delivery to 12v side till SOC get to about 85% SOC.

 

[bushpilot]

Following!

Prior to our ‘20 expedition all our cars / trucks and most of the motorcycles (and rv) have all had conventional flooded / lead acid batteries.

For many years - I've employed and used some type of “intelligent” battery maintainer (battery minder, battery tender and now NoCo) to keep the vehicle batter charged - because vehicle use can be somewhat unpredictable if not irregular - the vehicles all get “plugged in” as soon as they’re parked....because the amount of driving we do (on a daily or even weekly basis) can be irregular sometimes our "daily" drivers don’t move for severals days or weeks (especially if were away).

So far, It’s nothing for me to get 7 yrs out of a conventional lead acid battery (although I can’t seem to get more than 5 yrs out of the group of RV batteries).

Our ‘23 f150 Powerboost is the 1st car/truck with a non lead acid battery.....just the same I’ve installed a a battery charge connection…..leveraging a NOCO intelligent battery charger (set to AGM (actually didn’t even need to set it - it automatically detected the AGM).

I have forscan and will start monitoring the SoC.

Here’s my convenient batteries connection, using a POWERLET (hella style) plug. - it makes for a convenient breakaway type connection should I get in a hurry or forget to disconnect.

 

[UGADawg96]

A regular flooded cell battery is not hurt by a long term low amp charging. I've had them last 8 years.

So far, It’s nothing for me to get 7 yrs out of a conventional lead acid battery

Been in Florida for 16+ years and have not had a regular car battery make it to 4 years across multiple vehicles and multiple battery brands. They always die on us sometime around 3.5 years. And even the ones with the 5yr warranty too.

 

[bushpilot]

Been in Florida for 16+ years and have not had a regular car battery make it to 4 years across multiple vehicles and multiple battery brands. They always die on us sometime around 3.5 years. And even the ones with the 5yr warranty too.

are you using a battery maintainer?
I'm in houston....20+ yrs and get 5 yrs (even w/ occasional use of a maintainer).

 

[Gros Ventre]

Been in Florida for 16+ years and have not had a regular car battery make it to 4 years across multiple vehicles and multiple battery brands. They always die on us sometime around 3.5 years. And even the ones with the 5yr warranty too.

Batteries don't like heat. Spent two years on the island of Guam (latitude 8º N) batteries there have a high failure rate because of the heat. Had a 6 year old battery that failed within the first year, then it's replacement lasted a little over a year. Learned about NAPA there. That battery was a NAPA and it failed in less than 3 months back in the states... NAPA made good on it, its replacement went 8 years.

 

[UGADawg96]

are you using a battery maintainer?
I'm in houston....20+ yrs and get 5 yrs (even w/ occasional use of a maintainer).

Negative. But we run all our vehicles at least once a week for a minimum of 30 miles. They usually get at least a hundred miles a week.

 

[UGADawg96]

Batteries don't like heat.

Neither do us humans. We're moving north and out of FL when I retire in ~11 years.

 

[Gros Ventre]

Neither do us humans. We're moving north and out of FL when I retire in ~11 years.

 

[wrgrimes]

These trucks appear t be electric sinks.
I put my PowerBoost to bed last evening at 85%.
I checked today- 77%

The key was in the house, so I was not periodically waking from a snooze.
Some have suggested locking- does that really make a difference?
I have a lot to learn about the battery dynamics.

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