12-volt battery died; Ford "working on a patch"

[Williamffe]

Weird, it seems because this is not a issue on all FFE they didn't apply that TSB at the factory for 2014? the only thing I can compare it to is when smartphone apps get an update it apply's to every user. @ NightHawk, did you see from the dealer to get the TSB update on your 2014 FFE, or did it already include it from the factory?

I'm on the fence getting an FFE and is a big concern for me.

 

[WattsUp]

I'm on the fence getting an FFE and is a big concern for me.

Keep in mind that most people don't experience this issue. Besides, it is known and there is a TSB for it (in the very off-chance that a brand-new 2014 FFE will exhibit the behavior). My 2013 has not exhibited the behavior.

In any case, I wouldn't say this rare and relatively minor (and merely potential) issue should keep you "on the fence" about getting an FFE. After all, some other EVs have actual "big concerns" that are far worse. For example, the Leaf's current high-voltage battery can noticeably lose capacity after only a couple years (and from then on just gets worse). My FFE is nearly two years old and has seemingly lost zero range (and I believe almost all FFE owners would tell the same story).

I'd take an FFE over a Leaf, or probably most other comparable EVs currently on the market, any day.

 

[JTCalif]

Keep in mind that most people don't experience this issue. Besides, it is known and there is a TSB for it (in the very off-chance that a brand-new 2014 FFE will exhibit the behavior). My 2013 has not exhibited the behavior.
[...]
I'd take an FFE over a Leaf, or probably most other comparable EVs currently on the market, any day.

Ours is 2 and 1/2 years old, with no problem. Had the TSB done "just in case", but never saw a need for it.
Car has served very well, and we recommend it. Besides its good performance, I like that I could find parts (the one time I needed them) at so many Ford dealerships: there are 3 within easy range of me, much more than for other EV makes. Helps that most parts are common to the fossil-fueled version of this Focus.

 

[davideos]

I could try to get the dealer to swap the 12v battery for a new one, but that wouldn't stop whatever caused the discharge when the EVSE is left plugged in overnight with an already fully charged HV battery.

I'd go ahead and get the replacement battery. If the battery is bad or has been stressed (drained and recarged), the capacity of the battery drops and the internal resistance rises. When the resistance rises, small changes is current being pulled from the battery will show large swings in the observed voltage. Could explain what you are seeing.
If it is the battery, and it very likely is, then your troubles will go away with the new one. If it doesn't, then I would only get concerned if they haven't fixed it by the time the 3yr/36k mi warranty expires.

 

[windsurferk]

I'm experiencing the same problem. I've come out to my car twice now and it's been dead. I jump it and the high voltage battery is fully charged. In both cases the vehicle had been connected to the level 2 charger for more than 24 hours. I'm led to believe that the 12v battery is drained by being connected to the charger for an extended period after the vehicle is fully charged. I also suspect that go-times would improve the situation as they would provide a charge each day. Unfortunately, my vehicle stopped connecting to MFM and we cannot get it re-paired. Taking it back to the shop today. I'm hopeful that they will at least replace the battery and apply TSB-13-9-19 (not sure if that's already been applied).

 

[sefs]

I'm experiencing the same problem. I've come out to my car twice now and it's been dead. I jump it and the high voltage battery is fully charged. In both cases the vehicle had been connected to the level 2 charger for more than 24 hours. I'm led to believe that the 12v battery is drained by being connected to the charger for an extended period after the vehicle is fully charged. I also suspect that go-times would improve the situation as they would provide a charge each day. Unfortunately, my vehicle stopped connecting to MFM and we cannot get it re-paired. Taking it back to the shop today. I'm hopeful that they will at least replace the battery and apply TSB-13-9-19 (not sure if that's already been applied).

I've experienced this as well. What happens is the 12V battery is drained and the HV battery is done. The car drops the EVSE and then realizes "oh crap, the 12V still needs charged". It then closes the EVSE again. A minute later, "high voltage is done bro, you can drop the EVSE". A second later "oh crap, 12V still needs charged". It does this forever until the 12V is dead. The only reason I picked up on this is that I have a clippercreek CS-90 and the contactor is extremely loud when it closes or opens. One night, I just keep hearing it open and close, open and close, open and close. I went to sleep then woke up to a bunch of "12V low" warnings in my email. I remedied the issue by just disconnecting the J1772, and leaving the car in ready to drive. This allowed the 12V battery to charge. This is a definite bug.

 

[hybridbear]

I'm experiencing the same problem. I've come out to my car twice now and it's been dead. I jump it and the high voltage battery is fully charged. In both cases the vehicle had been connected to the level 2 charger for more than 24 hours. I'm led to believe that the 12v battery is drained by being connected to the charger for an extended period after the vehicle is fully charged. I also suspect that go-times would improve the situation as they would provide a charge each day. Unfortunately, my vehicle stopped connecting to MFM and we cannot get it re-paired. Taking it back to the shop today. I'm hopeful that they will at least replace the battery and apply TSB-13-9-19 (not sure if that's already been applied).

I've experienced this as well. What happens is the 12V battery is drained and the HV battery is done. The car drops the EVSE and then realizes "oh crap, the 12V still needs charged". It then closes the EVSE again. A minute later, "high voltage is done bro, you can drop the EVSE". A second later "oh crap, 12V still needs charged". It does this forever until the 12V is dead. The only reason I picked up on this is that I have a clippercreek CS-90 and the contactor is extremely loud when it closes or opens. One night, I just keep hearing it open and close, open and close, open and close. I went to sleep then woke up to a bunch of "12V low" warnings in my email. I remedied the issue by just disconnecting the J1772, and leaving the car in ready to drive. This allowed the 12V battery to charge. This is a definite bug.

Interesting. We were just gone for a week and the Focus sat plugged in and fully charged. We had no 12V battery issues. I did set a few Go Times with no HVAC over the course of the week though.

 

[NightHawk]

Yep I had the same issue, so I don't leave the car plugged in for a long time after a charge.
I also manually charge the 12v battery with an external 12v car battery charger once a month or whenever my accessory port voltmeter shows the voltage has dropped down well under 12.0V.
Just charged it up today since it was down to under 11.5V after not driving the car for a week.
Daily Go times or remote starts will charge the 12v battery for the time that is active however and can help to maintain the charge.

 

[jeffand]

NightHawk is your FFE 2012? It seems the FFE has two charging levels one is a maintainer charge at about 13.4 volts. This seems to be operational when the high voltage battery is being charged. The second is when the car is turned on. This raises the battery voltage to 14.0 volts or more. This is meant to recharge the 12 volt battery more quickly, and to operate vehicle accessories. Either their is a defect in the battery, or something is discharging the battery. The question is why some FFE see it and others don't? In the car their are multiple CPU (computer) that are running in the car.
If one of these don't shut down then it is possible over time that the battery would be discharged.
A test you can perform using a digital volt meter.

1) Once getting home measure the battery voltage with the car parked but on. (This should be about 14.6 volts)
2) Next turn off the car and re-measure the battery voltage after about 2 minutes. (The battery voltage of should of dropped to about 12.7 volts.)
3) Wait about 30 minutes and re-measure the battery voltage. (Battery voltage should still be above 12.5 volts.)
4) Plug in the charging cord wait about 1 minute before checking the battery voltage. (Battery voltage should be about 13.3 volts)
5) Recheck the battery voltage after an hour or more of charging. (Battery voltage should be about 13.4 volts)
6) Once the charging has been completed for an hour or more the voltage should stay above 12.0 volts.
7) Recheck the battery voltage after 8 hours or more. You should see less than 0.25 volts drop then in step 6.
Note: How cold the battery is will affect the voltage reading. I checked the battery as 32F and it measured 12.04 volts after being parked for 2 hours.

If you find reading that are more than a 0.5 volts lower than what are listed could indicate a charging problem.

 

[hybridbear]

Note: How cold the battery is will affect the voltage reading. I checked the battery as 32F and it measured 12.04 volts after being parked for 2 hours.

This could absolutely be a factor. The BCM measures and tracks the 12V SOC to know when to charge the 12V and for how long. With Torque Pro I can see this data for the Energi. Right now in our cold winter where the 12V temperature is usually under 40 F the SOC usually reads 80-90%. When the weather was warmer it usually read 98-100%. When we went to California last week and were in warm weather the 12V SOC began to show 98-100%. Now that we've returned home to cold weather it is back to showing 80-90%.

I have never seen the car put more than a 5 amp charge on the 12V battery while driving. When the SOC is in the 98-100% range the charge is low enough that the PID reports 0 amps (it only displays in 1 amp increments). Sometimes it even says -1 amp, indicating that the 12V may even be discharged slightly to provide the needed current to power the accessories. When you turn the car off and the DCDC converter shuts off the 12V often shows to be providing 20-40 amps of current depending on what lights are on, etc. The Fusion Hybrid pretty much always is charging the 12V while driving. The Energi charges the 12V while charging the HVB and thus rarely needs to charge the 12V while driving.

I need to get FORScan configured with the Focus Electric so that I can track this data there too. I imagine that it works similarly to the Energi.

 

[EVA]

Had an odd thing happen this week - the 12V battery alarm went off. The car started sending me text messages about every 2 minutes that the 12V battery was low.

The car was plugged into the Level 2 charger, everything was working just fine high voltage-wise.

I have a 12V plug cigarette to USB adapter that displays voltage, amperage and temperature. Can't remember the exact voltage when the charger was plugged in (think it was 11 volts, maybe a little lower). As soon as I unplugged the charger, voltage dropped quickly to 6.9. I put a jump starter battery (one of those small Lithium-ion deals), the voltage got up to 11.3 quickly, and the car started. 14.7 volts after that.

I left the car on for about an hour. Then put it on a 12V charger overnight. Recharged the jump start battery and left that in the glove compartment in case something goes wrong again.

The only difference - we only drove the car very short distances during the week. Didn't really use it a whole lot. That's the only reason I can come up with that the 12V battery would gradually die like that - not enough driving time to fully charge the battery. Like a dope I forgot to cancel the 5 days of Go Times in the morning (didn't need them since the car wasn't moving).

We keep the car plugged in when not driving it. Have done that its whole life. Around 2.5 years old and that's the first time this has happened.

If the 12V battery dies again, I'll take it back to the dealer. If it never happens again, I'm not too worried about the 12V battery life - end of lease is December.

 

[NightHawk]

Had an odd thing happen this week - the 12V battery alarm went off. The car started sending me text messages about every 2 minutes that the 12V battery was low.

The car was plugged into the Level 2 charger, everything was working just fine high voltage-wise.

I have a 12V plug cigarette to USB adapter that displays voltage, amperage and temperature. Can't remember the exact voltage when the charger was plugged in (think it was 11 volts, maybe a little lower). As soon as I unplugged the charger, voltage dropped quickly to 6.9. I put a jump starter battery (one of those small Lithium-ion deals), the voltage got up to 11.3 quickly, and the car started. 14.7 volts after that.

I left the car on for about an hour. Then put it on a 12V charger overnight. Recharged the jump start battery and left that in the glove compartment in case something goes wrong again.

The only difference - we only drove the car very short distances during the week. Didn't really use it a whole lot. That's the only reason I can come up with that the 12V battery would gradually die like that - not enough driving time to fully charge the battery. Like a dope I forgot to cancel the 5 days of Go Times in the morning (didn't need them since the car wasn't moving).

We keep the car plugged in when not driving it. Have done that its whole life. Around 2.5 years old and that's the first time this has happened.

If the 12V battery dies again, I'll take it back to the dealer. If it never happens again, I'm not too worried about the 12V battery life - end of lease is December.

Try unplugging the car from the EVSE after its charged and leave it unplugged until you need a charge.
The 12v battery should hold its charge for at least a week without driving if it unplugged unless the 12v battery is weak and needs replacing which may be the case.