Another dead 12v battery thread.

So I last drove/charged my car Jan2. I was going out of town so I plugged it in before I left on Jan 11 (battery was already fully charged). Jan 20th I get a 12v batt low please plug in message around 4pm I had someone unplug the car put the 12v battery on a charger at 2A. It was initially down to 3.4V. putting the battery on the charger resulted in a flurry of text messages. I don't want to see my international roaming bill for 300+ text messages it generated before I could log into MFM and turn it off!!! The charger errored out and when plugged in again a day later the battery was down to 2.5V!!!!

I get home today and it was still 2.5V Try to charge it at 12A and the charger fluctuates in the 6.5-9.5V range??? Usually the voltage displayed while charging is in the 14-16v range. I let it charge for a couple of hours and I could hear relays and other stuff clicking when it would briefly flirt with 10V. I gave up since I feared damaging my charger. It seemed to be acting like it had nearly a dead short. I pulled the + terminal off and hooked the charger directly to the battery terminals. It started charging on the 2A or 12A setting as normal with indicated charge voltage of 15+. I doubt this will do much since it seems to want to pull more than 12A just sitting there doing nothing? I guess it will go on a flat bed to the dealer for warranty repair. All before I even have plates for it yet!

I believe the 12v battery is damaged It wouldn't charge above 12V. I was able to get enough charge into the battery to turn things on again. It sparked pretty good when I put the terminal back on. My Ammeter which I don't know if it was accurate said it pulled about 2.5A for about 3-5 seconds and I could hear what I believe is the coolant pump going then I went back down to basically 0A. If the Ammeter is correct then my battery charger must be failing since it supposedly can put out 12A. I am guessing it was the coolant pump which killed the 12V battery. If that is the case I would think it would be simple for ford to fix this by turning on the DC/DC converter when the pump requires power.

My 2014 FFE's 12v battery was getting discharged too quickly early on when I left it plugged into the charging station at home overnight and leaving it plugged in after the HV battery was fully charged.
It seems to be OK if I use value charge set for only a 4 hour period (12am-4am) and leave it plugged in after that however.
Leaving the car unplugged after a 25+mile drive that charged the 12V battery, it will stay above 12.0V for nearly a week.
But I wouldn't leave it without charging or driving more than a week.

I monitor the 12v level daily with a plug-in voltmeter accessory in the cabin 12V accessory port.
I keep a portable 12v battery car starter device (small lithium-ion based) in my FFE for emergencies.
I also have a premium Sears external 12v battery charger I use at least once a month to make sure the 12v battery can charge fully way before it gets close to a too discharged state.
If needed on days you don't drive the FFE, I found a 15+min remote start or Go-time (without climate control) will charge the 12v battery with a 14.5V level for that period.

With all this, I have managed to keep my FFE's 12V battery at high enough charge to start the car reliably now for 3 months straight. Before that, I had a couple times the 12v battery got low enough it wouldn't start the car (<11V or so) but then I just charged it with my external charger for 30min or so. But now that I'm proactive, I can prevent it from getting that low and not be surprised at the last minute when I need to drive the car to an appointment.

I do think a lot of the FFE 12v batteries may have their life impaired sitting on a dealer's lot for up to months without adequate 12v battery maintenance, so may want to get a dealer to swap out for a new 12v battery and then maintain it properly at home. I agree that Ford should activate the DC-DC converter to charge the 12v battery when it senses the level has gotten down to under 12.0V or so automatically, since the small 12v battery is the weakest link in the system apparently.

NightHawk said:

With all this, I have managed to keep my FFE's 12V battery at high enough charge to start the car reliably now for 3 months straight.

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Something seems to be wrong with your FFE, no?

I never do any of this and my FFE always starts, for two years straight now. Nor have I ever worried about leaving the car plugged into a charger (Level 1 or Level 2) after it has finished charging, which I do often at work and at home, for hours at a time (either before I leave work, or overnight at home). I'd say I do about 50/50 charging at Level 1 and Level 2.

WattsUp said:

NightHawk said:

With all this, I have managed to keep my FFE's 12V battery at high enough charge to start the car reliably now for 3 months straight.

Click to expand...

Something seems to be wrong with your FFE, no?

I never do any of this and my FFE always starts, for two years straight now. Nor have I ever worried about leaving the car plugged into a charger (Level 1 or Level 2) after it has finished charging, which I do often at work and at home, for hours at a time (either before I leave work, or overnight at home). I'd say I do about 50/50 charging at Level 1 and Level 2.

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Al this talk of battery drain and is odd to me as well. I have a 2012 FFE. I drive it maybe twice a week, sometimes less, usually about 20 miles or so. My ave. monthly is about 174, but that is from an active October that had twice to usual drives. I use a level 2 clipper creek charger at home. The only charger I have used. I often will leave it plugged in for several days and do nothing at all with it. Never had a bit of problem with it or the battery. I know the car sat at a dealer for several months and got only about 100 miles put on it. It was listed on cars.com and had the milage posted for that time so I know at best they started it a few times to either move it or check the charge. I wonder if it is an odd programing issue in those cars that do suffer the drain issues? I don't wait for sounds or cycling, I don't check battery levels or pre-start with go times, I just pull the plug, get in and push the button and go. When I get back home I stop the car get out and plug in, then shut the garage door and forget about it until a few days later when I repeat the same.
I hope those who have this issue can get it resolved, maybe a re-flash of the computer would help with this? Good luck!

This might be a 2014 FFE issue since you guys with 2012 or 2013 FFEs haven't seen it?
Others have reported here, so its not an isolated issue.
I've observed the excessive 12v battery drain after leaving it plugged in for several hours after the HV battery is fully charged happens only if I had "charge now" mode selected, but I normally use "value charge" now and I haven't had the issue in that mode.
The 12v battery voltage does drop a bit after a week or so of not using the car at all and not plugged in, down from typically 12.3V to around 11.8V or so - still enough to start the car however. So it would probably take a couple weeks or so before the 12v battery would drop enough to fail to get into ready to drive mode, but with my voltage monitoring I can catch it way before that so its not an issue for me now, by simply not leaving it plugged in all the time and/or use "value charge" mode and drive the car (or use a remote start or go time) at least once a week or so. I normally do drive it once or twice a week anyway, so its not anything special for me to do now.
If nothing changes, I'll just probably request the Ford dealer put in a brand new 12v battery whenever I need to take the car into the dealer for service, like the once a year inspection/tire rotation.

NightHawk said:

I normally use "value charge" now and I haven't had the issue in that mode.

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Fwiw, I only ever use "Charge Now" mode and, as mentioned, haven't had any 12V issues either.

Just adding additional data point. I have a 2014 and leave it plugged in all the time to my level 2 charger. I do drive it most days but sometimes travel for work and it will be plugged in for up to a week at a time with no issues. I do not use value charging at all.

triangles said:

Putting the battery on the charger resulted in a flurry of text messages. I don't want to see my international roaming bill for 300+ text messages it generated before I could log into MFM and turn it off!!!

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I don't know what cell carrier you have, but in our experience with AT&T we have never been charged for incoming text messages received while we are on international roaming. I hope you don't get billed for them.

Posting an update:
There is nothing wrong with my FFE or it's 12v system. I'm about 90% sure the problem was caused by my JuiceBox having false GFI trips. Apparently I still had my go times programmed. I believe the coolant pump runs off the 12V system. I'm guessing that I have a roughly 70% false GFI trips whenever the contactor closes to power the car. Eventually the 12V battery got drained so much that the car got stuck in one of it's cycles where the cooling pump was running so it completely killed the 12v battery. The problem was compounded by magic smoke leaking from my smart charger when trying to charge the 12v battery. I suppose it's possible the additional current draw of the coolant pump could have killed my charger but I doubt it since it was quite old. I bought a new 12v charger and have had no 12v battery issues since I charged it back up. I guess the moral learned here is don't leave your car plugged in on a buggy JuiceBox when you travel.

TSB 13-9-19 calls for reprogramming the PCM if the customer is experiencing a dead 12V battery.