How will I know when the 12 volt battery needs replacement?

[Ev Blau]

Replacing the 12v on your own is a PITA.
In my view, this alone makes it different than the above references to a 12v in an ICE vehicle (it is not an EZPZ task when it dies). My thoughts:

1. ICE vehicles don‘t lock you out when the 12v goes bad.
2. You cannot easily swap out the MMe 12v. To remove the 12v, you have to remove way more than just remove the FRUNK trim panels, and will likely need dealer intervention.
3. Getting stranded in the MMe is more arduous than an ICE vehicle (jump the FRUNK, remove panels, etc.)

In my view, if you do not frequently drive your MMe (especially when it’s cold), it’s worth considering a battery tender. The MMe will not intervene to charge the 12v until its charge drops to an unacceptably low level (again my opinion) and repeated cycles of this are problematic for the 12v. I find it easier and more efficient than the suggestions of others (use an inefficient 120v charger to prolong the charging process, etc). It’s soooo easy to simply connect the battery tender to the pigtail in the MMe.

I just prophylacticly replaced my 12v after 3 years because it outweighed the risk of getting stuck in the cold again at an inopportune time (like most folks, if I’m out in the cold it’s only because I’ve got things to do…places to be). I also acknowledge I’m more risk averse about getting inconvenienced in the cold than most people.

Good morning. I wish I could parse your statement “It’s soooo easy to simply connect the battery tender to the pigtail in the MMe.” Huh? Please explain to the uninitiated who want to learn from you. Thanks.

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[RickMachE]

Good morning. I wish I could parse your statement “It’s soooo easy to simply connect the battery tender to the pigtail in the MMe.” Huh? Please explain to the uninitiated who want to learn from you. Thanks.

A Battery Tender trickle charges a 12v battery properly. It can connect via clamps like jumper cables, or via a pigtail, which is connected to the positive post on the battery and a body ground via nuts, "permanently". You then plug the pigtail into the battery tender. Post #31 shows a picture of the pigtail sticking out of the vent in the frunk tub, a very rudimentary install, where he has to pop the frunk and plug in.

My Lightning, which is used less often than the Mach-E, is setup this way (but to the fender wall, not the frunk).

If you use the vehicle regularly, this is unnecessary. Further, if you're not going to do this yourself (which you aren't), then paying someone to do it would be silly. It's not needed with normal usage of the vehicle several times a week.

If your car sits for 2 weeks between uses, then that would be different.

 

[Ev Blau]

A Battery Tender trickle charges a 12v battery properly. It can connect via clamps like jumper cables, or via a pigtail, which is connected to the positive post on the battery and a body ground via nuts, "permanently". You then plug the pigtail into the battery tender. Post #31 shows a picture of the pigtail sticking out of the vent in the frunk tub, a very rudimentary install, where he has to pop the frunk and plug in.

My Lightning, which is used less often than the Mach-E, is setup this way (but to the fender wall, not the frunk).

If you use the vehicle regularly, this is unnecessary. Further, if you're not going to do this yourself (which you aren't), then paying someone to do it would be silly. It's not needed with normal usage of the vehicle several times a week.

If your car sits for 2 weeks between uses, then that would be different.

You’ve convinced me to just drive the car! But I’m calling you for a ride if I get stranded!

 

[JSW]

My Lightning, which is used less often than the Mach-E, is setup this way (but to the fender wall, not the frunk).

I prefer your more permanent solution/location. Once I realized the frunk light goes off after a few minutes and I could just leave it open on those occasions when I made use of the battery tender, I lost motivation to make it permanent/pretty. Maybe now that I’m retired……

 

[Hammered]

Some people take things to the absurd. I can tell you that on the F-150 forum, a large number of people replace batteries without load testing them, often while in warranty. I don't get it. Lack of commonsense IMO.

Because the ford batteries suck as does the charge strategy. It's easier to replace the AGM in less than 30 minutes than it is to deal with dealer nonsense because of the vehicle constantly sleeping modules.

 

[Maquis]

Because the ford batteries suck as does the charge strategy. It's easier to replace the AGM in less than 30 minutes than it is to deal with dealer nonsense because of the vehicle constantly sleeping modules.

The OEM battery in every Ford I’ve owned in the last 25 years lasted longer than anything I’ve replaced them with. My 2000 F150 holds the record at 12 years.

 

[Kamuelaflyer]

I cut the holes without removing the covers. No big deal, just do it delicately

Exactly.

 

[dml105]

Drive the damned car and quit worrying about it.

I love you too.

I’m not talking about messing with it. I want to know if it’s normal, because my warranty is ending next month.

 

[Maquis]

I love you too.

I’m not talking about messing with it. I want to know if it’s normal, because my warranty is ending next month.

I sincerely believe you’re worried about nothing.

The best thing to settle your angst is probably to take the car to your dealer and tell them that you think there’s a problem and ask them to test the battery. They may or may not test it. If they do, you’ll know if it’s OK or not.

 

[HuntingPudel]

The OEM battery in every Ford I’ve owned in the last 25 years lasted longer than anything I’ve replaced them with. My 2000 F150 holds the record at 12 years.

The 12V in my ‘14 Fusion Energi went kaput within 3 months of ownership. The Optima in my T/A was installed in 2002 and still cranks the big high-compression Pontiac like it doesn’t have spark plugs in it. Most of my other car batteries have been in the 5-7 year range. Just illustrating that sometimes we get lucky, sometimes we get a lump of coal. Usually we are somewhere in-between. ?‍?

 

[Hammered]

The OEM battery in every Ford I’ve owned in the last 25 years lasted longer than anything I’ve replaced them with. My 2000 F150 holds the record at 12 years.

And how many of them were AGM? Lots of AGMs failing to charge properly.

 

[RickMachE]

Because the ford batteries suck as does the charge strategy. It's easier to replace the AGM in less than 30 minutes than it is to deal with dealer nonsense because of the vehicle constantly sleeping modules.

You do you.

Me, I'm going to stick with doing a load test on a battery, which most auto parts stores do for FREE (if you don't want to go to the dealership), BEFORE spending hundreds of dollars on a new battery that may not be needed.

 

[Hammered]

You do you.

Me, I'm going to stick with doing a load test on a battery, which most auto parts stores do for FREE (if you don't want to go to the dealership), BEFORE spending hundreds of dollars on a new battery that may not be needed.

You fail to understand, a load test has no bearing on charging. The BMS logic is poo.

I did do me, I'm running an LFP in parallel and always have 100% SOC on the AGM and 4x the reserve capacity as the factory AGM setup that's supposed to have ~90ah capacity. Resting voltage at -10c is 13.1v

 

[RickMachE]

You fail to understand, a load test has no bearing on charging. The BMS logic is poo.

I did do me, I'm running an LFP in parallel and always have 100% SOC on the AGM and 4x the reserve capacity as the factory AGM setup that's supposed to have ~90ah capacity. Resting voltage at -10c is 13.1v

I can accomplish the same solution with a Battery Tender. I would never waste that kind of money nor add that weight. Glad it worked for you.

 

[kram]

I am on my Third 12 volt battery, my 2021 AWD extened range was towed from the rail yard in Ayer Mass, it was delivered to the dealer ( front wheels up and dollys on the rear wheels ) the vehicle had the keys hanging from the inside mirror locked. to no avail could we pop the frunk and had to pop the door open, now I understand why it was 2 months late from the orginal ETA ( this was December of 2021 - could not locate a AMG battery from anyone but our local Chevy dealer had one in stock - that battery lasted about one year, we are now on battery #3 Motorcraft and everything has been excellent - we think all the up-dates killed battery # 2 , so far we have not had any more problems and we love the Mach E and its excellent in the New England weather

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