12V battery replacement poll

[MidAtlanticLightningClub]

This summer we were getting ready to pull our trailer from MD to WI, then back home through Michigan's Upper Peninsula and the east side of Lake Huron. With limited service options along parts of the route and a 3-year old truck/12v I replaced the battery with a slightly larger one prior to starting the trip.

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[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.

 

[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 an 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 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

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