12V battery replacement poll

[Robert1380]

Wouldn’t just plugging in your charger to the charge port accomplish the same thing, even if you’re not charging the battery? I’m not trying to be a smart ass, I really want to know cuz I’ve been wondering about this as well. I have several Battery Tenders and considered installing the wiring to utilize one of them. I just didn’t think it was necessary if I left the truck plugged in.

You'd think so, but you'd be wrong - BTW, no offense taken at the question, it is a reasonable ask.

Here's a good post about how the LV 12v battery gets charged from the Mach-e forum applies to the Lightning as well. The only thing I would add is be sure to use an AGM suitable charger.

https://www.macheforum.com/site/threads/how-to-get-failed-otas-to-install.29749/

I repeat, be sure you get a trickle charger suitable for AGM batteries - they are different and some trickle chargers do not have an AGM mode.

The NOCO Genius1 has an AGM mode, as do many others.

Appreciate the info.

Chi, lemme ask you something else. Does the 12v battery charge while you’re driving? I’d think it would have to back feed from the HVB to keep it up to operating level, or do all the accessories run off the HVB during periods of driving? Another forum member mentioned the battery only charges while you’re charging the main but that wouldn’t seem enough to keep it functioning properly.

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[TaxmanHog]

Appreciate the info.

Chi, lemme ask you something else. Does the 12v battery charge while you’re driving? I’d think it would have to back feed from the HVB to keep it up to operating level, or do all the accessories run off the HVB during periods of driving? Another forum member mentioned the battery only charges while you’re charging the main but that wouldn’t seem enough to keep it functioning properly.

The DC/DC inverter/charger is active when the truck in in RUN / Ready to Drive mode, it feeds a maintenance level of current to charge the LVB and run all 12 volt systems. In other words, the HVB is feeding the LVB via this inverter/charger

 

[chl]

Appreciate the info.

Chi, lemme ask you something else. Does the 12v battery charge while you’re driving? I’d think it would have to back feed from the HVB to keep it up to operating level, or do all the accessories run off the HVB during periods of driving? Another forum member mentioned the battery only charges while you’re charging the main but that wouldn’t seem enough to keep it functioning properly.

Yes, as others have mentioned it does, but....it was never enough to get my battery up to the 80-85% SOC needed for the OTA...customer service told me to drive around for 1 hour, I did that and then tried the install, did not work, I drove around for another hour or so, still did not work...overnight charging to 90% from somewhere around 60% did work however...

Certainly how often you drive and for how long is a factor. I don't drive long distances or for long times and don't drive every day, so a trickle charger is what works for me.

The other post might have meant that just being plugged in to a "charger" (EVSE) is not enough, the EVSE has to be actually providing energy to the truck for charging the HV battery...that is the truck has to go through a charge cycle of some duration.

 

[Robert1380]

The DC/DC inverter is active when the truck in in RUN / Ready to Drive mode, it feeds a maintenance level of current to charge the LVB and run all 12 volt systems.

Thank you sir! I’m still trying to familiarize myself with how these trucks work. Appreciate it

Yes, as others have mentioned it does, but....it was never enough to get my battery up to the 80-85% SOC needed for the OTA...customer service told me to drive around for 1 hour, I did that and then tried the install, did not work, I drove around for another hour or so, still did not work...overnight charging to 90% from somewhere around 60% did work however...

Certainly how often you drive and for how long is a factor. I don't drive long distances or for long times and don't drive every day, so a trickle charger is what works for me.

The other post might have meant that just being plugged in to a "charger" (EVSE) is not enough, it has to be actually charging the battery.

We have similar drive habits so I think I’m gonna follow your lead and grab one of those chargers. You mentioned the Noco Genius 1. I noticed they make several. Is there any advantage to grabbing one of their more expensive chargers?

 

[No Oil HaHa]

I replaced mine when it failed at approximately 85k miles. I got another Motorcraft battery.

 

[Robert1380]

I replaced mine when it failed at approximately 85k miles. I got another Motorcraft battery.

Damn. That ain’t bad.

 

[chl]

Thank you sir! I’m still trying to familiarize myself with how these trucks work. Appreciate it

We have similar drive habits so I think I’m gonna follow your lead and grab one of those chargers. You mentioned the Noco Genius 1. I noticed they make several. Is there any advantage to grabbing one of their more expensive chargers?

I don't think the more expensive ones would be needed.

BTW, to use with an SAE cable (which I already had) you need an adapter from NOCO too.
Their charger uses a different plug end. I did not know that before I bought it. Of course you could use the alligator clips or the rings (they can be separated from the alligator clips).

https://www.amazon.com/dp/B005DUMADC?ref=ppx_yo2ov_dt_b_fed_asin_title

But there are other decent AGM trickle chargers to choose from as well.

I did find one error in the NOCO instruction "manual" (which you have to download) in that the pulsing red is not an indication of a battery below 75% charge, just an indication it is charging.

I'll attach the manual fyi.

 

[Robert1380]

I don't think the more expensive ones would be needed.

BTW, to use with an SAE cable (which I already had) you need an adapter from NOCO too.
Their charger uses a different plug end. I did not know that before I bought it. Of course you could use the alligator clips or the rings (they can be separated from the alligator clips).

But there are other decent AGM trickle chargers to choose from as well.

I did find one error in the NOCO instruction "manual" (which you have to download) in that the pulsing red is not an indication of a battery below 75% charge, just an indication it is charging.

I'll attach the manual fyi.

Interesting. Looks like the Noco 1 is only a 1 amp charger VS their others that are 3 and 5. Thanks brother.

 

[chl]

Interesting. Looks like the Noco 1 is only a 1 amp charger VS their others that are 3 and 5. Thanks brother.

Yes a bit slower, but for trickle charging and maintenance, speed is not necessary.
Your welcome.

 

[TaxmanHog]

Interesting experience for myself today, I have not driven the Lightning since yesterday afternoon, today my wife did her errands with her car while I stayed at home to monitor a fencing crew working on our property.

I wanted to access the trucks departure time settings via Ford App, but the truck was not responding to any LTA communications, no status update, door lock confirmation (well past BT range) and error out when I tried to switch on my departure routines, which was temporarily shut off when I parked her yesterday.

So, I go out the the garage, with FOB & PAAK device, jump in the truck, no immediate screen wake-up, and when I pressed the START button, I was greeted with the R2D2 tones instead of the normal start tones (reminder that I wasn't buckled up).

At this point the truck has started and now is communicating LTA and Ford App & Truck are responding to commands and data request, {Lock Door, Location refresh, Switch on Departure time schedule}

My relatively new (August 2025) DieHard is probably been stressed by me leaving the Veepeak BT plugged into the OBD2 port for several months ongoing, not helping is the fact that I also have relatively short drive cycles so the DC/DC charging sessions aren't worth a hill of beans, I only plug in and charge once a week, either Saturday or Sunday evenings.

I've unplugged the Veepeak and stowed it away, plugged in the EVSE for ONLY departure timed preparation Friday morning (Setting SOC level to 50% well blow my current 75% current SOC) this will reserve energy availability only for servicing the departure preparation, I anticipate the PTC will activate overnight and certainly when the departure event kicks off, that ~ 15 minutes of energy might give a little extra boost to the LVB, and minimize HVB burdens warming the truck cabin, I'll also waste a bit of energy ~3kWh warming the battery.

 

[mr.Magoo]

It's kind of funny that people are being reccomended by Ford to take the car for a drive to charge it... I mean, it's not like the engine might bog up from all the idling or someone dying from Co2 poisioning. You can just turn off the shutdown timer and leave it running in your driveway/garage for as long as you want.

What you can do to give your LVB some extra juice (if you drive short distances) is just to leave the truck running when you park it, turn off the climate control and headlights and leave it, it'll shut itself off after 30min.

For those using OBD loggers, there's three values that are helpful to keep an eye on (in addition to SOC, voltage and all the standard stuff) and that's the cummulative discharge values, and can be read from the BCM / 726 using these PIDs:

0x22401C	CUM_DIS_SLP
0x224026	CUM_DIS_OFF
0x224021	CUM_DIS_RUN

They're 16bit values / 2 bytes and have a .01 resolution.
Unit is C(oulomb), 1A x 1s



Another noteworthy thing is that I'm wondering if Ford have toned down the charge curve for the LVB. The top chart is from September this year, the other one from November last year. 36A now (which is still a lot) vs. 70A a year ago and I've seen as high as 100A in the past, so that could potentially have been frying batteries as well, along with all the other issues.

All that said, I changed my OEM for a Diehard 626 days ago and despite draining it completely by accident it's held up quite well, my SoC does not seem to drop below 60% despite leaving the truck sitting for days (unplugged) and driving semi-short 20-25min distances (commuting to work)

 

[jamelski]

I won’t change it till it fails.

2021 Mach e before totaled. 78k miles 4 years old. Stock battery zero issues with OTA ect.

Car was driving m-f 40% battery each day and charge to 90% every day. Sat -Sunday 20% each day back to 90% and always plug in at home

2024 lightning 15 months old 25k miles same driving/ charging and zeros issues

I’m believe with no data but the above . That the real problem I have seen people have with LVB die early is ….

1- don’t drive a lot
2- don’t charge every day
3- them weirdos that only charge the car/truck to 50% once a week to save the HVB life

 

[mr.Magoo]

That the real problem I have seen people have with LVB die early is ….

1- don’t drive a lot
2- don’t charge every day
3- them weirdos that only charge the car/truck to 50% once a week to save the HVB life

Phew, saved by the bell as I charge to 80% when I need to (once per week or once every other)

To answer the original question, I suppose I'll keep changing mine when it acts weirdly altough some claims that's not a scientific enough determening factor.

 

[TaxmanHog]

Just as I suspected, being plugged in my departure event for 0755 hrs has caused the Lightning to determine a battery warming phase should start at 0707 hrs, it quickly ramped up to 10.6 KW at the moment, let's see how long this phase lasts, it'll eventually slow or pause before cabin warming phase kicks off at 0750 hrs. While this is going on the LVB is getting some love as well.

Now 0725 hrs and the energy rate has jumped to nearly 18 KW, this has been suspected to be a battery charging effort on top of the warming effort. note the data pane for charging details is still suppressed and only says preparing cabin.

0756 update: the animated fan icon never appeared only the static icon showed from 0750 presently, energy is continuing to flow to the truck in a pattern that's indicating cycling of the PTC so I think the cabin is actually getting heated up.

Chart of energy flow and cumulative energy to the moment, it'll be about 10 kWh to prepare for the drive:

After heading the the truck, all was normal for displays & sounds, the cabin was toasty warm
Final tally of energy used was 9.9 kWh

 

[hturnerfamily]

While I've no issues with my ~40+month original LVB battery, with a truck build date of July 22, and probably the battery itself built several months before that, my recent 'red ring of death' non-chargeable issue made me consider the LVB as a potential culprit - or, at least I had hoped it would be that simple.

I was forced the remove almost everything from the frunk - wow! who would've thought you could hoard -away that much junk! Tools, emergency items, charge EVSE and cables, adapters, a folding chair, and more... : )

I removed the sliding door cover to the LVB, although I also realized now that I could have saved myself some time and convenience by simply using the external 'jumper' studs...anyway, I applied my trickle-charger's alligator clips to the primary battery terminal bolts(not the accessory terminals), and plugged in the charger. While I don't have a battery voltage checker, I felt like the battery showing 'Charging' would be an indicator, and I would then let it charge for several hours, or until 'full', if it was low...

after a while, I tried plugging in my EVSE again - no go. Still the red-ring.

The LVB was still charging. The small trickle-charger only has a 'blinking' Green light as a charging indicator.

I then set out to take a picture of the LVB battery size/type, and use that to research a replacement, as I imagined that this would be the answer to my charging woes. Even if not, with the truck over 3 years 'young', and over 62,000 miles, it was 'time', anyway...
FoMoCo BHAGM-H3 12V 35Ah 60RC

Well, I quickly found that no 'in-stock' options lie in the local area, from the typical sources, and even the Ford dealer had none. I then set out to contact my selling dealer, instead, as I was heading back down south near that location the next day, anyway, in my wife's car. Nope, none there, either, although they put me onto another dealer, within 25 miles from me, who DID have it in stock, and, I might add, at the much lower attractive price, versus what some online sources had quoted. $132 vs $200 or more. All of the online sources also add a nice big 'shipping' cost, too., and how would you then also receive your 'core charge' credit? Who knows... because....

Since the local Ford dealer could get me in that day, I let them also do a diagnosis, planning that it was really only the LVB as the real issue. It was not.. as they could immediately and clearly see, thru the truck's data, that the LVB was just fine, and actually at 97% capacity. The HVB, though, was where the issue lie - module 7, cell 63, was at about 3.8volts, versus all others at about 4.8, or something like that. That module replacement is a different story for another time : ) but, successful, I might add.

So, in the end, I still don't have a 'new' LVB, and, well, until it starts to give me fits, it will continue to serve me until then... I have a follow-up module replacement APPOINTMENT on Tuesday, to check coolant levels, AND the LVB status, just in case. A tire rotation can't hurt, too.

yes, I could simply go out and get that replacement LVB, put it in the bed, and ride around with it as my 'backup', until needed... but, then, the warranty period would start at that purchase date, rather than when you actually start using it. Oh well. Hard choices.

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