HYBRID 12V Battery Mystery SOLVED

[SafetyGuy]

Appreciate the thought Andy. Just with normal use where they stay on a few seconds after lock/unlock, door opening... already the cheap plated plastic reflectors are melting like some have reported -you mean the actual outer clear plastic cover is melting when people intentionally have them switched on for an extended period?

I don't have any hitch receiver (major regret) or trailer wiring exposed to do a light, but I do have USB and power points on the pigtails in the bed thanks to @Maverick_Innovation_Designs. Maybe there's a product I could plug in that would draw enough to trigger the charging without putting extra wear on headlights or high box lights.

I can't quite remember the post that drew my attention to the possible issue, sorry about that.

Either way, I replaced my box lights with LED bulbs and am happy with them.

So you are seeing some melting from the reflector material? That would do it for me as well and I am glad I changed mine.

I did not see any indications of such when I changed mine, but I did it shortly after we bought our truck...and it was still winter.



Have a good one,

Andy

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[Tall Hobbit]

2022 lariat hybrid ambient temp 84. 12v was on noco g5 . This am drive 60 miles then after 3 hours drove 25 miles off 20 mins drove 6 miles, off 30 mins then drove 28 miles. Off for 1 hour 10 mins. Then drove cig monitor showed 14.7 v did not change with head lights on, or off Or with high beams on. Then additionally with MAX AC on or off. CIG MONITOR Stayed 14.7 v !!!

If we're talking about cig monitor voltage while driving, no I haven't seen noticeable change. Played around with headlights and fan speed to no effect. Next will try parking lights. On repeated starts what I noticed was starting acc voltage before 'cranking' was higher than normal each time, and climbing, but not during operation. I typically run 14.3-14.9 most days. Incidentally, soon after my AGM batt was replaced, I would exit the highway and it would cycle down from 14.x to 12.x while driving, doing nothing differently than less load. Then it stopped doing that for whatever reason.

I also have the @Maverick_Innovation_Designs installed on the back of my truck...absolutely wonderful construction and very happy with them.

They do now have a new design out that allows higher draw for higher power demands...if I didn't already have mine, I would definitely get the new ones!

They allow a higher draw, is what I am thinking and that might work in your favour.

However, you can plug in a a 12 volt cooler (one of my plugs at the back is a 12 volt power port/lighter socket for this exact purpose) into yours if that is what you have, as that is a good amount of draw from the power port!

Maybe it will work for you. Just a thought that works with what you suggested.

Have a good one,

Andy

You as well. I did get that 65A USB port, but after seeing OP got no effect from plugging various loads into his inverter, I would think drawing power from anything connected to the pigtails would similarly have no effect.

No joy perhaps, but I'd like to believe my 'cranking' voltage is actually increasing and might be a good thing.

 

[SafetyGuy]

If we're talking about cig monitor voltage while driving, no I haven't seen noticeable change. Played around with headlights and fan speed to no effect. Next will try parking lights. On repeated starts what I noticed was starting acc voltage before 'cranking' was higher than normal each time, and climbing, but not during operation. I typically run 14.3-14.9 most days. Incidentally, soon after my AGM batt was replaced, I would exit the highway and it would cycle down from 14.x to 12.x while driving, doing nothing differently than less load. Then it stopped doing that for whatever reason.




You as well. I did get that 65A USB port, but after seeing OP got no effect from plugging various loads into his inverter, I would think drawing power from anything connected to the pigtails would similarly have no effect.

No joy perhaps, but I'd like to believe my 'cranking' voltage is actually increasing and might be a good thing.

It is my thought, from my reading here, the 120 volt socket will not help increase the 12 volt battery charge level (due to 120 volt power comes from the drive battery directly).

But, I feel that the rear pigtails are obviously part of the 12 volt battery circuit that having a load applied may work, as demand is being placed on the 12 volt system.

I will have to get my 12 volt cooler, plug it in and see what happens!

Andy

 

[MattTX]

I think the worst thing about this is that Ford have been having parasitic draw issues for over 10 years and multiple vehicle lines. I knew a guy who bought a new F-150 in about 2014 or 2015, I don't remember exactly how long he had it but I'm certain it was less than 18 months. In that time the truck killed at least 3 or 4 batteries, and just like our current situation the dealership / Ford weren't able to find or fix the issue. From what I remember he got the dealership to take the truck back and give him a full refund, granted his parasitic draw was considerably worse than what most of us are experiencing, but still, more than 10 years and they haven't learned how to keep parasitic draws to a minimum.

Unfortunately with modern carputers it's probably not possible to turn them off completely, but you'd think those super smart well paid engineers would come up with a way to compensate for that (Ha! As I was typing compensate the first thought that came into my head was Big Truck Syndrome which then led me to the thought of well actually, yeah, a bigger battery would help compensate for a constant electrical draw!).

Like mine that’s why! Thanks

Which brake light strip did you get? I bought one last year and it didn't work correctly, it would light up once then not again, sometimes the lower brightness running lights would be on, other times they didn't work, and the turn signals wouldn't work off the trailer plug, they had to be wired directly into the rear turn signal wires. After a little researching it sounds like the cheaper brake light strips have these compatibility issues with a number of modern trucks, not just the Maverick, so I'm curious to know if there are inexpensive ones now that might have fixed the problem.

 

[Mavster Mechanic]

My $10 trailer plug light is dim when parking lights are on, bright when braking, and blinks bright when either turn signal blinks. I'm ok with that for $10.

The point was two fold:
My high brake lamp is blocked by my soft topper. (Flated) And also I wanted to see if it triggers 12v battery to charge to 100%. So far, it does. (11 days in a row)

 

[Dad]

After reading through 7 pages of fascinating commentary that rivals the still yet unresolved mystery of UFOs, this one post tickled my fancy....

I am as old as Glen Baker so he might be able to relate a thing or two. Recalling back in the day (as in last century) when we had analog gauges, I remember every time I turned on the headlights, the BATT one would jump a bit before settling back into where it started from. And sometimes, it would jump and stay there. Sometimes the idiot light would come on, other times not.

Since we didn't have "compooters" back then, the only thing that would do this is the voltage regulator in the alternator. This would be a simple transistor that kind of act like an on/off switch to prevent overcharging of the battery.

While possible and perhaps someone more knowledgeable than the average DIYer, could something in the alternator be factored into the nuances of this discussion? What would happen one took the alternator out of the equation? Call me curious, but as a former forensic accountant, we always relied on addition by subtraction to narrow down the clues to the end result.

Wasn't that one of the jobs of the old school alternators . . . regulate the voltage?

 

[Glen Baker LLC]

My 65 Mustang, 70 Challenger both had alternators but we're equipped with separate voltage Regulators. Mounted on the firewall or on the fender

 

[samspritzer]

Wasn't that one of the jobs of the old school alternators . . . regulate the voltage?

It depended on whether one had one built in. I believe it was towards the 70s and 80s when manufacturers started phasing them out from the mechanical ones to solid state to built in.

The point I was trying to make is electrical current is relative; like a light switch, it's on or off. The same with computers; their instructions are in the form of bits, 0 or 1. While there are so many things along its path from point A to point B, it still behaves the same in its raw form. No one has ever figured out how to harness it completely.

 

[MakinDoForNow]

It depended on whether one had one built in. I believe it was towards the 70s and 80s when manufacturers started phasing them out the mechanical ones to solid state to built in.

The point I was trying to make is electrical current is relative; like a light switch its on or off. The same with computers; their instructions are in the form of bits, 0 or 1. While there are so many things along its path from point A to point B, it still behaves the same in its raw form. No one has ever figured out how to harness it completely.

The recharge rate used to be adjusted by changing the voltage only with the battery accepting what it will at the reduced voltage. Today the system voltage has to be increased to supply all current needed (wire size part of it). Since voltage is higher than desired as battery approaches 90+%. The bms has to limit current not voltage. There seems to be a difficulty in controlling current flow to that needed. I wonder if one possible answer might be a dedicated dcdc regulator (full "key on" time maintainer) on the positive battery post??? At least on hybrid although any time current flowed out of battery maintainer might restart depending on design(?). In any case if dcdc converter is supplying less than what bms wants for battery the on post voltage controller would adjust voltage from buss up or down???

 

[Tallymav]

Ugh - I'd be happy if my SOC% and Volts were matched like that - 60% & 12.1V.
After 4 hr drive yesterday - got up to 65% SOC (float level started after 20 min about), from 52% IIRC.
This morning resting - 63% (ya it held!), and 11.9 V (boo it didn't). (bad battery at this point)

Thanks for observational skills with your different setups.

I haven't attached my trailer hitch yet, and don't think it came with wiring kit, but had for so long I don't recall. Time to get busy.

Or per the EB poster that found the rear AC outlet with night light was enough draw (he has inverter) to prevent AS/S from kicking on - perhaps I can find a high draw powerpoint light.

Does your scanner have these PID's available for cumulative charge/discharge?
Curious what level of matching you have?
This pic was day after a drain usage of doors open - BMS motivated to get it matching again - which it did - currently 32 Ah matching.
I've observed how close these are determines the BMS willingness for rate of charge too.

This is great detective work! I think it potentially explains a lot. When you add it to the (theory) that a lot of early mav hybrids were shipped with FOMOCO battery that was probably fairly shit It explains even more because almost everyone who swapped it out for a good AGM battery says that their problem was solved. The little bit extra resilience from the AGM probably overcomes a lot of these trickle drains. But it doesn't get at the root if you are correct.

 

[HeyBales]

On Max Auto Fan speed is at max also (6).
True or not, I have no proof of external charging being tracked but from what I have read the BMS is located on the negative battery post with requirement charger (nothing else either) is not attached to battery post but to other body ground so that the BMS can see the activity. I agree that when I was driving with cig monitor showing 14.7 that significant charging may not have been occuring based on leaving cig monitor active after 12 minute drive and 20 minute rest my reentry shoes battery at 12.4 volts while after opening door, closing, prior to touching push button (it appears that just opening door causes about 0.2v reduction due to truck waking up so I believe battery should actually be closer to 12.6v, need memory on cig monitor to verify, of course). This battery is 15 month old Ford max series bxt99rt4. I will install monitor with memory onto battery with body ground that I can read with phone app. It will need it separate key on charging bat, of course .

Just for clarity that's a battery sensor attached to the negative post, with wires going to the BdyCM which handles the BMS function.

While it obviously senses amps going both directions charging and discharging - it only logs in the BMS charging while key on.
I do have proof.

External charging as you would do with key off (I know videos show it being done with key on with FDRS connected reading it) - does not log or report any charge going into battery.
It only reads the discharge that happens with engine off, and during the sleep time.

That battery sensor is the same as any you buy off Amazon that has a shunt and is installed on the negative line, and reports the stats to a monitor. That monitor can be live only, or feed into an app, or have some memory ability to report later - depends on your price point.

Or you can get that other battery monitor that hooks to Pos & Neg and provides Volt readings. It can be decent, especially if it has settings for battery spec's.
It'll give that ability if you think something bad has been happening - to keep phone on outside of locked truck - and watch where the volts go for the 60-75 min.
Actually - you'll want a baseline as a good graph, compared to other times.
With memory option - it should show the hourly blips thru night as modem keeps connection up.

Do you have a tow package to have trailer wiring and Tow Module?
Or the 120V option to have inverter and whatever module supports that?

 

[HeyBales]

If we're talking about cig monitor voltage while driving, no I haven't seen noticeable change. Played around with headlights and fan speed to no effect. Next will try parking lights. On repeated starts what I noticed was starting acc voltage before 'cranking' was higher than normal each time, and climbing, but not during operation. I typically run 14.3-14.9 most days. Incidentally, soon after my AGM batt was replaced, I would exit the highway and it would cycle down from 14.x to 12.x while driving, doing nothing differently than less load. Then it stopped doing that for whatever reason.

You as well. I did get that 65A USB port, but after seeing OP got no effect from plugging various loads into his inverter, I would think drawing power from anything connected to the pigtails would similarly have no effect.

No joy perhaps, but I'd like to believe my 'cranking' voltage is actually increasing and might be a good thing.

Your cycle down to 12.x (12.8? if reading is correct) was probably when it was thinking a fully charged battery was obtained. So little to no charging amps.
That's when the test with fan @ 6 or headlights on would show the jump back to 14.x and more amps given.

But sounds like your battery has dropped below a SOC% limit now, and it's got no desire to do what Mavster has found.
Same as mine.

You have tow package & wires? (which means a tow module)
You have inverter and 120V option?

Cranking voltage - you mean it doesn't drop as much, it's staying higher during the relay engagement?
Of course that power point Voltage reading is inaccurate for compares after a charging session, like driving. Next start after that should be much higher probably.
Morning reading before going to On, that's a good point to keep noting, as that's a much more valid reading, even with slight draw with doors open and lights on.
I've noticed if I sit there until lights go off, then turn key to Accessory position - my reading is slightly higher. To your point of a bit of recovery.

 

[HeyBales]

I think the worst thing about this is that Ford have been having parasitic draw issues for over 10 years and multiple vehicle lines. I knew a guy who bought a new F-150 in about 2014 or 2015, I don't remember exactly how long he had it but I'm certain it was less than 18 months. In that time the truck killed at least 3 or 4 batteries, and just like our current situation the dealership / Ford weren't able to find or fix the issue. From what I remember he got the dealership to take the truck back and give him a full refund, granted his parasitic draw was considerably worse than what most of us are experiencing, but still, more than 10 years and they haven't learned how to keep parasitic draws to a minimum.

Unfortunately with modern carputers it's probably not possible to turn them off completely, but you'd think those super smart well paid engineers would come up with a way to compensate for that (Ha! As I was typing compensate the first thought that came into my head was Big Truck Syndrome which then led me to the thought of well actually, yeah, a bigger battery would help compensate for a constant electrical draw!).

This thread isn't really about dealing with parasitic draws (non-desired higher amp), usually those are intermittent.
Those don't actually seem to be striking that many. But when they do, an already bad health battery is going to be impacted more than a good healthy one.

Microdrains are expected - people want their fob unlock or keyless entry to work, or remote access, alarms, ect.

All the stuff you are reading here is about the normal low charge rate the BMS gives the battery, and the low SOC% it seems willing to drop to and stay at on a new battery.

 

[Nuclear One]

Some of you will laugh.
Some of you will cry.
Some of you will say "Holy Crap that's amazing!"
Some of you will say "Holy Crap that's dumb."

Here goes.

Fact: 2022 Hybrid (and others) actively drain a 12 volt battery to the computed 80% charge level.
Then do not try to add charge to the 12 volt battery until a computed 60% or lower charge is reached. God only knows why.
For 3.5 years my 12v battery has been "maintained" at about 60% charged. Always a resting voltage of 12.1 or 12.2.

Fact: running your headlamps will force the 12v battery to be 100% charged given enough time. (DRL will not do it. Parking Lamps only will do it.)

Fact: running your vents blower at speed 6 or 7 will force the 12v battery to be charged to 100% given enough time.

Fact: attaching a trailer, 4-pin or 7-pin will force charge the 12v battery to 100%.

Theory A: the truck needed to detect 12 volt demand, and above a certain wattage to trigger 12 volt charging.

Why would fan level 6 trigger battery recharging and fan level 5 would not? Why would full headlamps trigger battery recharging, but DRL would not?
Did the truck detect demand to run my camper fridge and coach battery?

I tested this last part. From Amazon I ordered a $10 LED brake light for the 2" hitch receiver with 4-pin connector.
Wow! The LED brake light pulling no power when not braking, and only 4 or 5 watts when braking DOES TRIGGER 12 volt battery recharging to 100%.
It's not the electrical demand that triggers recharging. It is simply thinking a trailer is there that triggers recharging.

Theory A shot down.

But this explains a lot.
This explains why some people have more 12v battery issues than others.

Those that drive at night a lot have more battery charging by happenstance.

Those that use fan speed 6 or 7 have more battery charging by happenstance.

Those who connect trailer wiring (and you don't even need a trailer!) have more battery charging.

Not a permanent fix. But a work around. Some of you may prefer running your headlamps more often over plugging into a home charger.

My 12v battery has been 100% for ten days in a row now. And is maintained at 12.7 or 12.8 volts. But I need to do one of the three "triggers" above or it rapidly starts to decline.

More to come...

I used Forscan and changed battery charge level to 95% and got a good AGM battery....no problems for 2 years....not is on EB but the 12v system affected both hybrid and EB

 

[HeyBales]

I used Forscan and changed battery charge level to 95% and got a good AGM battery....no problems for 2 years....not is on EB but the 12v system affected both hybrid and EB

So you did both at the same time?

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