CMax-Traveler

1. Did the 2013 ever have the "mileage upgrade" performed (came out in Aug 2013)?
2. Are the numbers from the dash readouts or figured from pump gallons?
3. Any A/C use?

1) Yes, the 2013 had the "mileage upgrade"

2) The numbers are from the dash readouts, but the two fill-ups which make sense the dash was 2.5mpg higher than the pump.

3) I used the A/C on the return trip, which was pretty consistent with last year's trip.

Do you track your gas tanks with Fuelly? I'd be curious to see if you see this improvement over 6+ months. I've found that one trip doesn't mean much because wind & other conditions can have such an impact. For example, a few weeks ago we did a highway trip in our Energi and got better than 50 MPG because there was no wind. This past weekend we did a similar trip and struggled to get 45 MPG because we were fighting a crosswind. On a recent 1000 mile road trip to visit family we used about 4 gallons less than previous trips because we had the wind behind us both northbound & southbound, usually we have crosswinds on this trip. Perhaps your recent results in the 2015 are just due to wind & not to any changes with the car.

Here's my fuelly.  I gave up on tracking the 2013 last August.  http://www.fuelly.com/driver/cmaxtraveler

It's possible this trip was a fluke, but there wasn't much wind.  With as many times as I made similar trips in the 2013 year you'd think conditions would've been similar on at least one of them and I never achieved higher than 45mpg highway.  Note the highway driving was entirely on eco cruise.  But good point, little things make big differences when you're this high in the MPG range.

Hey everyone, I have an interesting anecdotal report here on the difference between the 2013 and the 2015.

I frequently drive from Boston up to the White Mountains to go hiking.  I also recently traded up from a 2013 C-Max to a 2015 C-Max.  I did so this past weekend, with some interesting results.  The trip, overall, was about 290 miles, and involved 80-90% highway driving, mainly at speeds of 60-70.  I made this exact same trip several times last year in my 2013.

In the 2013 C-Max, I never got better than 44mpg on the round trip, and was usually in the 42.5-43mpg range.

In the 2015 C-Max, the trip this weekend ended at 50mpg for the trip (I made a similar trip earlier this year which resulted in 46.5mpg, but that was with only 400 miles on the car - I now have 2700 miles).

Needless to say, I'm quite impressed with the changes made between the 2013 and the 2015.  Every tank since I got the car has been a 600+ mile tank and I haven't drained it empty (except the first tank; the car wasn't topped off at the dealer).

Just thought I'd share!

I'll add another interesting electrical observation regarding my radio. On several occasions, I've driven to pick up someone and had to wait for them, so I shut off the car but still had the radio on. After what I thought was a rather short period of time, the radio turned off by itself and I think there was some wording in the display regarding 'battery low' but I don't remember. I never timed these periods but perhaps they were around 15-20 minutes. 

 

Am I expecting too much for the radio to play for a longer amount of time without turning the key to accessory position? I really don't remember, but I may have actually had to blip the key into start, and then turn off again. I have the base SE with no options, no touch screen.

Actually, this "battery low" condition you mentioned is different than the 15 minute power bus mentioned by drdiesel1.  I've experienced it myself several times.  I don't recall if I had the car in accessory or if it was off, but whichever it was, after sitting in the car having the radio on for a few minutes, apparently it's able to detect that the charge on the 12v is too low, and the 4" center display flashes a message about "battery too low, powering off", and then powers off the radio.  This was much shorter than the typical 15 minutes you're given, after which things just power off with no message.

When you flip the key on to re-engage the radio, it also re-engages the DC-to-DC converter, thus recharging the 12v battery.

My thumb drive always had the flashing LED. If your theory were valid, the amperage draw would not have

changed as the APIM would have still been active and drawing amperage after the drive was removed.

How do you explain the amperage draw turning off after removing the drive, if it wasn't the drive causing the

APIM to stay active ????????????

USB has two data pins and two power pins... the LEDs I've seen on thumb drives are powered by the power pins, regardless of the data - and then flash upon data usage.

Not knowing anything about how it's actually set up... is it possible that the power pins are connected directly to the battery rather than switched via the APIM?

Considering you said the meter shuts off after 15 min. You're unable to monitor long term. This would be key

to finding the high amperage battery killer. Without a way to monitor it long term, you're kinda stuck with not knowing.

 

I've never known of an amp clamp that can read below 500 milliamps, unless it's an expensive micro amp clamp.

No, I can't do long-term monitoring.  But my point was that it's not a constant parasitic load, and a standard parasitic load test won't help.  It's some module that randomly comes on and stays on, and that would require a very extended, nightly, parasitic load test for potentially months until the problem recurs -- and it would require much more patience than any of us have.  And then, once it does happen, good luck figuring out which module it was, since the car will have died and all you have left is a log of the current draw - not what was drawing it -- unless you also come up with a way to be notified on one of those random nights when it happens so you can go and pull fuses until it stops.

Unfortunately, after the car "goes to sleep" it periodically "wakes up" and does stuff (gets a midnight snack, takes the dog out - goodness knows what).   (I think someone said what it does but I don't remember.)  You can see my all night current monitoring results here in post #25.  A half hour after going to sleep the current jumped to 3 amps for 6 seconds.  Then it periodically went to 0.2 amps for 30 seconds.  (My minimum measurement capability was about 20 mA.)  I had hoped to build a current monitor that I could check to make sure the car had "gone to sleep" but with all the insomnia going on I realized that you would have to keep checking all night!  Obviously, if it stuck ON at 3 amps, you could have a dead battery next day.

 

I wonder if a lot of batteries (including mine last winter) tested "bad" because they were being repeatedly discharged excessively but not quite enough to prevent starting the next morning.  So you go along for weeks or months not knowing what is happening until the battery goes low enough to prevent a start.  I wish we new the lowest voltage that would still energize the car.  From my experience I know that 3.5 volts is too low!

Those results are pretty awesome, but not surprising - things are constantly waking up and going back to sleep, as evidenced by all of the buzzing, whirring, fans, etc. that have been documented.  Some of the things I'm pretty sure it does is opening/closing the grill flaps, cooling the HV battery, maintenance on the fuel system pressure, and others.  I'm assuming Ford has a bunch of C-Max'es with known problems in a lab somewhere with similar test equipment hooked up to try and trace this problem - and if they don't, they should.

I know from my experience that 5.7 is too low to energize the car.  But I also know that, in the months I've been monitoring my car, other than the morning that it didn't start, I've never seen the "resting" voltage drop below 12.3v.  So I don't think it's an issue of the charged state gradually falling until it's too low, I'm pretty sure it's a sudden thing - something turns on and gets stuck on that drains it.  I genuinely wish Ford luck in figuring out what, though, for all of our sakes!

It is true that many cars suffering dead 12 volt syndrome have had their batteries changed. That was done for two reasons: first, in the early days, as a blind shot at solving the problem, and second because a battery's ability to take a full charge is diminished when it is run down to a very low charge. The batteries were not changed because of a bad batch of batteries.

My dealer told me: Many many C-Max 12v batteries were replaced that were not bad, just because they had discharged.  As a result, Ford instituted a policy that the batteries must be tested thoroughly and fail before a replacement would be approved.  But even after that, a large (but smaller) number of 12v batteries still tested as failed and needed to be replaced.  As for the underlying cause as to why they've tested bad, I have no idea.  Bad batch?  Unlikely.  Discharged too often?  Perhaps.  Something else?  ??  Realistically, only Ford can know this by testing the failed batteries.

Don't shoot the messenger, but it seems to me that if any of these problems that folks here have concluded are the "cause" of their battery issues were true, then ALL (or at least most) of us would also have them.  IOW, if there is a fundamental design flaw somewhere, it wouldn't be so isolated (and thus easier to fix).

 

That would lead me to believe it IS a bad battery or other "bad" critical part that sometimes is made incorrectly or installed incorrectly, or manufactured incorrectly, but most of the time is not.  Which is why most people do not have these issues.  Even though most of us here are not engineers, we have to at least stipulate that Ford's engineers (or at least some of them) are competent, and would otherwise have solved this issue long before now.

Yep, that's 100% accurate - many of the problems that people have concluded are the problem should mean everyone would have the problem.  But there are many other factors that could contribute: the way the car is driven, the frequency and duration of trips, whether it sits unused a lot, the environmental conditions, manufacturing differences in the cars, bad batch of radios, etc. ... and whatever those factors are trigger a specific set of circumstances causing the various types of problems people have encountered, and causing the vast majority of owners to have no problems at all.  We're all grasping at straws here, and sadly, it seems at the moment that Ford engineering is as well.

I see you're using a clamp type amp meter to read parasitic load. Unfortunately, unless it's a Micro ($500 to $700 bucks on average) amp clamp, it's incapable of reading below 500 milliamps. You can read down to 1 M/A with a DVOM setup inline with the battery on the 10 amp scale. Some meters even offer M/A readout, so you don't need to covert it. Most systems top out around 35 M/A. I have come across a few trucks that read 50 M/A's and never cause problems (they have much larger batteries) with starting, even after a few weeks.

 

On smaller systems like the C-Max, my limit would be the 35 M/A threshold. Anything above that will cause battery problems.

If anyone is interested in how to setup a DVOM to read a parasitic draw, I can explain it or even do a short video. If anyone

is interested, just post the request in this thread.

 

The cars systems will go to sleep without locking the car. Some modules can take as long as 40 min. to sleep.

They never shut off, so there is a voltage draw from every module to retain memory. It's called KAM. Keep Alive Memory.

This is what your meter can not read and makes you think there's not a problem with an amperage draw on the system.

I would bet the car has at least a 20 M/A draw all the time after the modules sleep.

As I mentioned in my post, my meter has a specified resolution of 400A +/- 0.1A - so in theory it can measure down to 100 milliamps.  In practice, I'd say I can distinguish between 200milliamps and zero, but probably not less.

When my car is fully "asleep" the meter reads 0.1 or 0.2 amps.  Which is around the smallest load it can detect, but it's definitely negligible.

The 12v battery in the C-Max is rated at 40Ah.  Which means that with the smallest load detectable by my meter, the battery should not discharge fully for over 200 hours.  Even if we say my meter can't accurately measure less than a full amp, that's still 40 hours.  In my personal experience, my 12v battery discharged in less than 9 hours.  That would indicate either a battery that cannot hold a charge (but it passed all tests at the dealer), an undercharged battery (but it indicated ~80% charge at 1am prior to the discharged condition at 10am), or a parasitic load of at least 3-4 amps.  Which would be easily detectable by a non-Micro meter.

So, my meter can detect a parasitic load that would be required to drain the car in the observed duration, and I have not witnessed any load of that magnitude.

If you know of a case in which the problem was solved by the charge routine update and/or the infotainment update, please post details.

I'm not aware of any cases where the DC-to-DC converter software update solved things.  If I remember correctly, the DC-to-DC software update TSB (13-5-1 and 13-6-23) was initially targeted at resolving a cold weather problem, where the 12v wasn't receiving sufficient charge in cold (below freezing) weather when being run for short periods of time at high electrical load.  I think they may have eventually updated the TSB to apply to all temperature conditions, not just cold weather.

My question was more whether or not a problem still remains there.  The DC-to-DC converter plays the role of alternator in the C-Max, so it's unique to hybrids.  Because we don't have a starting load requirement, they're smaller batteries than most cars.  Under regular use, from my voltmeter monitoring, the DC-to-DC converter seems to maintain a SoC around 70-80% -- which, over time, will result in sulfation (and thus, failure) of the battery.

In my car, I've had two problems.  One, a good battery ends up drained for no reason overnight - likely a module turning on and staying on, thus draining the battery.  So, that problem is still out there.

But the other problem is I've had two 12v batteries go bad and need to be replaced.  And it seems a LOT of C-Max 12v batteries have gone bad.  It has been blamed on a bad batch of batteries - but so many, produced over such a long timeframe?  I'd be more inclined to say it's the C-Max causing them to go bad b/c of maintaining an insufficient state of charge.  Now, disclaimer: that's just speculation; I'm not an engineer; I don't know that much about car batteries, and I don't have any direct evidence to back that up... so I'm just fueling Internet rumors here.  But it seems to me to be a better explanation for so many bad batteries than I've seen anyone else come up with.  I'm not sure how to test that, though, besides going through and examining all of those dead 12v batteries - which I hope Ford is doing. So... thoughts?

you might have them check the BCM module for proper connection, esp the ground connection

They checked that the last time it was in; it appeared to be fine.

Interesting theory but nope. I hear always hear the fan on as its hot here in LA and I always use EV+ to finish on the top of the hill where my garage is. Plus I probably EV more than anyone here as well so the batts is more used than ICE. Start it the next day, fine...

Jus - you hear the battery ventilation fan on well over an hour after you've powered off the car?  I've heard mine on, but usually only for a few minutes after I leave the car - not hours later...

dmk,

It has been suggested in the past that the ventilation for the battery coming on and not turning back off might be a problem.  I've wondered if that's an issue, too, as all of the problems I've had occurred when the overnight temperature was within a certain temperature range -  low 50's (which I think is what it was last night in NJ)... but not every time it's in that range.  As far as I know, nobody has determined that for certain, and there are no TSBs from Ford to that effect... yet.  The thing that doesn't make sense to me is: if that were really the problem, it would probably be a software issue, and would apply to all C-Maxes, not just a few.  So who knows.

I'd recommend an experiment - if you notice it again, leave it alone and see if it's dead in the morning.  Not a great solution, but it would definitely be an excellent clue.

I'm curious - how did you test the 12V voltage?  Did you disconnect the battery, or did you test it live?  If it was live, it's likely that you weren't actually testing the battery voltage, since the car woke up when you opened it so there would've been a current draw... and I believe the DC-to-DC converter would've immediately started charging if it were low (although I'm not certain of this).

Anyway, great thought, and I'm curious to hear any additional info from others.

I'm not sure if this has been posted, but here is the 2014 car complaint index:

http://www.lemonlaw.com/carcomplaintindex.html

A couple things to note:

This is a RELATIVE index - so it's number of complaints relative to the number of that vehicle sold

While C-Max is on the list, it's nowhere near the top.  It is about 1/3 of the worst car, and just barely worse than the Prius.

Anyway, there's some hard data for ya.

CMax-Traveler. What was the process you used to check for a parasitic draw ? Thanks.

Here's the method I followed for testing for a parasitic load:

1) Open the rear liftgate, close all the doors, lock the car, then manually latch the rear liftgate by closing the lock mechanism with a screwdriver, so that the hazards blink once.  This makes the car *think* it's locked and closed, but gives me access to the rear compartment - the hazards blinking once confirms the car believes it's sealed. In theory, the car should eventually go to sleep on it's own, but I did this just to be certain. **WARNING** For anyone else trying this, be sure to unlatch the liftgate before closing it by pressing the open button, or you could damage your car!!!

2) Remove all of the rear battery covers, to give access to the 12v battery.

3) Clamp a 12v ammeter around the battery ground cable (the thick black one going from the battery to the floor of the car).

4) Wait until the car is asleep - 10 minutes or so.

5) Read the output on the ammeter.  Wait several hours, read again, etc. etc. etc.

My results were:

* Unlocking / locking the car generated a draw of 12-16 amps.

* Having the car unlocked and the hatch open there was a draw of around 5-6 amps.

* Having the car locked and all lights off, there is a draw of around 2-2.5 amps while the car is not in sleep mode.

* Once the car goes to sleep, the current draw falls to 0.1A.  Checking it for several hours after it's asleep, I've never managed to witness anything above 0.2A, but unfortunately my ammeter goes to sleep after 15 minutes so I can't monitor it continuously via a camera feed or anything like that.

Note: The resolution on my ammeter is 400A +/- 0.1A so we're right at the edge of its capabilities, but regardless, 0.2A shouldn't kill a good battery overnight.

Excellent post. Thanks for the link on the device. You mention sleep mode occurring 10min after being locked, but does it also happen in the same time frame if the doors are shut but UN-locked? 

Rob - in theory, the car should go to sleep after 10 minutes, regardless of whether the doors are open, closed, locked, unlocked, etc.  But since I don't know how it's actually programmed, I'd rather be safe than sorry, for testing purposes.  There have been anecdotes of people having more trouble who leave their cars garaged and unlocked, but there are many others of us who lock it regardless, so I'm not sure it matters.  But, since I'm in a testing mood, I'll test it out now with my ammeter and will report back.

EDIT: Yes, the load on my car did fall to 0.2A after about 15 minutes, despite being unlocked.  So it does appear to go to sleep regardless, at least in this particular instance.

Just a note that I added a fairly important comment to the end of my above post, for anyone wanting to replicate my methods.

thanks for the info. 

 

update:

dealer states the battery tested ok and was able to hold a charge. he said its a parasidic draw that is causing it. exactly like all the other dealers in this thread. they said they have a number of different tests to run on it tommorow and will call me with the results. i had no luck obtaining a loaner or rental through ford this time, hoping if it becomes even close to monthly issue or so they will provide vehicle. trying not to get too discouraged. not sure how battery goes from not being able to be jumped and showing 25% charge this morning to testing just fine a few hours later.

Adam,  your problem sounds a bit different than many of the other problems encountered... yours is the first I've read about where the car didn't die overnight.  Which makes me think it's likely a water intrusion problem with the electrical connections, since that would kill the 12v battery quickly and repeatedly, and yet the battery would still test good.  Especially since the dealer washed the car shortly before this started happening.  If it's a constant parasitic draw, the dealer should be able to trace and find it fairly easily.  And... if it is water intrusion, I could in theory see how that would prevent the car from being jumped, since that's essentially a short in the system.

The only additional thing I'd be concerned about is, once they find the root cause of your problem... even though the 12v tested good, since it will have died so many times, it's likely that the 12v itself will sooner rather than later fail to hold a charge, and need to be replaced.

Keep us posted, good luck.

RobMax, sorry for the delay here, I've been away from the forum for a few days.  I have one of these devices plugged into the 12v socket in the trunk compartment (the one that never powers off).  It gives a constant readout of the current state of charge of the battery.  The current draw from that device is on the order of a couple milliamps (yes, I've tested it), so it won't drain the battery.

Since we have people on here telling people they're wrong and insulting them, essentially telling them that they aren't capable of understand what's wrong ...  (ahem) ... I'm going to attempt to explain things.

--

With the 12v battery, in non-technical terms, there are two things to be concerned about: State of Charge, and Ability to Hold a Charge.  The voltmeter tells you the state of charge.  You can't tell the ability to hold a charge without fancy testing apparatus or a lot of patience.  In theory, a battery that is going bad could be reading 12.5v one minute, and then a few minutes later could drop to 5.0v despite having little to no load placed on the battery -- that's the ability (inability) to hold a charge.

When a C-Max goes into the dealership with a battery problem, Ford has instituted a procedure that the dealers must perform a rather expansive test using their battery testing equipment to determine the battery's ability to retain a charge.  If the battery fails, replace the battery.  If the battery passes, search for other causes.

Another problem is, with every time a battery is drained, its long-term ability to hold a charge is substantially reduced.  So, for a car that's persistently encountering a dead state, even if the battery is initially good, it will go bad quickly.

--

salman - I'm not entirely certain about your statement about the problems not being due to the charging routine or the batteries.  One of the updates performed on my C-Max was a software update to the DC-to-DC converter - the module that charges the 12v battery from the 120v battery.  I also noticed that the last time I had my car jumped, the car clearly extensively charged the 12v battery (you could see the added load on the 120v system on the dash gauges), and then for several days the "resting" state of charge was around 12.9/13.0v - but several days later it fell back to 12.5v.  So I'm wondering if perhaps there's a problem in the way that the car is charging the battery, or the state of charge that it maintains, which is causing batteries to fail.  Just speculation, who knows.

In my opinion, based on everything I've read on the forums, there are many different underlying problems for this issue.  One was the SE's radios not turning off.  Another was the water intrusion.  Another was addressed in that software update as a part of the recall.  And there are others I'm not recalling.  And there's still at least one (or more) cause that remains unknown, which Ford Engineering has stated somewhat publicly that they're still working on a solution for.

For some people, replacing the battery from the bad batch that Ford got solved the problem.  For others, replacing the radio solved the problem.  For others, replacing the fuel pump or wiring harness where water intrusion / corrosion was occurring solved the problem.  But for an unlucky few of us, the problem remains.

--

Just so this is out there... when I encountered my last dead battery, when it went from 12.5v at 1am to dead at 10am, I took the car into the dealer, and my 12v battery passed all of the "ability to hold a charge" tests.  So, as far as Ford is concerned, my 12v battery is good - it can hold a charge.  So something else killed it overnight.  As I mentioned, it didn't rain and I didn't wash my car, so it's not a water intrusion issue -- my radio isn't in the affected batch -- all my software is current -- and the dealer checked and cleaned all of the fuel pump connectors and other connectors that have shown signs of water intrusion, and they were fine.  The dealer essentially shrugged, said they checked everything and it looks good, and sent me on my way, wishing me luck.  Not especially satisfying.

So.  In summary.  In my specific case, where we've ruled out the other known problems.  *IF* my 12v battery can hold a charge (which, according to the testing, it can), and since the state of charge was acceptable at 1am... and the connectors weren't shorted out due to water intrusion... and the radio isn't bad... the only option remaining is a there's parasitic load that very intermittently occurs, for some as-yet-unknown reason.  I've performed my own parasitic load test on the car, and under normal circumstances, there is no parasitic load.  So there must be some module, somewhere, that very infrequently turns on and gets stuck on, causing the battery to drain.  And catching it in the act is next to impossible for a layperson, because of how infrequently it occurs.

--

If there's anything wrong in anything I said above, please let me know -- I want to understand the underlying causes and fix this problem once and for all.

--

EDITED 8/29 11:30am Eastern TO ADD:

One thing I did neglect to mention... In order to accurately test the state of charge of the battery while it's still in the car, the car needs to be in "sleep" mode.  There can be little to no drain on the battery, and the DC-to-DC converter needs to be inactive.  The car goes into "sleep" mode approximately 10 minutes after it's locked (and the lift gate is closed), and wakes as soon as the doors are unlocked.  So this means the only way to accurately check the voltage on a 12v voltmeter plugged into the lighter in the back is to look in the windows before unlocking the car and after it has gone to sleep.  Anything else and you're likely not measuring the actual state of charge of the 12v - you're instead measuring the results of the charger or a battery discharging under load, neither of which are accurate.

You still had brakes as the e-brake sort of proved.  What you didn't have was powered brakes.  You'll really need to mash HARD on the pedal to get any stopping power just like you have to crank hard on a steering wheel without power assist.  

I'm not sure about that... I stomped HARD and I'm pretty sure it went all the way to the stopper without resistance, and without any braking.  But I'll have to try it out again next time my battery dies to be sure.

Had a bit of a scare with my C-Max during one of my dead battery occurrences.

The dealer recommend I tow the car to them, without jumping the car.  So, after much hassle (ex: the tow truck didn't fit into my driveway; the shift lock release isn't where the manual says it is), we managed to load it onto a flatbed and off to the dealer we went.

Got it to the dealer and it was time to unload it from the flatbed.  Stepped on the brakes to gradually ease it off the flatbed and released the e-brake - the regular brakes don't work!  Fortunately we were able to grab the e-brake before my rapidly-accelerating car slammed into the car behind the flatbed. *WHEW* :drop:

So... if your 12v battery is dead, be forewarned - the regular brakes will only work once.  After you apply the brakes once, you'll only be able to use the e-brake.  Seems like a bit of a design / safety flaw to me.

As I stated in my previous post. Incomplete installation is not possible. It's either updated or it's not.

If the update was corrupted, the module that was being updated would be a door stop.

These cars have KAM memory that gets reset. The probable cause of his driving feel was

most likely a system reset. When the modules are updated (depends on the module) the memory

will also be reset. This will lead to a relearn over a few drive cycles before the car adapts to the driver again.

 

People that have never performed programming updates have no clue and make statements that

lead to more internet myths. It's amazing what people will believe :drop:

drdiesel1, it IS possible for the 13B07 update to partially apply, and I know this from personal experience.  And there are also many documented cases on this forum and elsewhere of the update partially applying for various reasons.

I understand what you're saying that a module update either applies fully or it doesn't - the possible outcomes of a failed update to an individual module are either that the module is not updated, or the module is dead.  True.

However, with 13B07, my understanding from talking to my dealer was that it was a very complicated update to many different modules.  A certain version of software or higher was required on the computer the dealer uses to apply the updates.  If it was below a certain version, then some of the updates would fail to apply.  Others would succeed.  So the result of a dealer applying the 13B07 update using a computer with the wrong version of the software was a partially updated vehicle which didn't perform correctly. To all appearances at the dealer, it seemed to work fine. The problems were only noticed when the owner took the car that they were familiar with and noticed things weren't right.  (Yes, there is also the KAM memory needing to relearn the driver, but that is a much less noticeable difference than the documented occurrences here).

In my case, on the failed update, the engine ICE on warmup cycles changed dramatically (this part applied successfully), but EV>60mph change did not happen (this part of the update failed).  So, clearly, in my case, and in many others linked above, the 13B07 update CAN be partially applied.

I would have a jumper battery to turn this into an annoyance, until FORD figures it out. It doesn't need to be like a flat tire.  My power Point voltage is 11.6volts when it has been sitting overnite in the garage, .2vmore at battery and still no problems in almost two years and 66K miles. :)

Paul,  I don't disagree with you.  I was genuinely hoping Ford had figured out and fixed the problem.  So now I probably will get one, I just don't see why I should have to buy one - if anything, Ford should pay for it.  I just have two concerns.  First concern, which I've seen expressed elsewhere, is that the jumper battery packs are unreliable, in that if you don't regularly use them and/or boost their charge weekly, you may end up with both a dead car and a dead jumper battery.  The other issue with using the jumper pack is that if it dies and you have to jump it, Ford has no record of it; without the jumper pack, they at least have the roadside assistance call records.

I'm very jealous of your 2 years / 66K miles with no problems - it seems clear that this is only a problem with some C-Max cars, not all of them, and there doesn't even seem to be a pattern, other than fewer SEL's than SE's have the issue, and even fewer Energi's.  For those of you who don't have this issue, the C-Max is an absolutely amazing car.  For those of us with the problem, the C-Max is still great, but not knowing if your car is going to start is nerve-racking, and when it doesn't start, it's beyond annoying.  Just luck of the draw, and I drew the short straw.

You have some pretty good data there, and I assume you've passed it on to Ford.

 

I also assume your car is parked outside at night?  I wonder what percentage of battery problems occur in a garage versus outside.  Not that I could imagine what that has to do with it, but it's still more data for Ford to tabulate and to try and figure out what's happening.  

 

If I were Ford I'd want a car like yours because it's very likely they *could* successfully diagnose what was going on (like perhaps hooking it up to a monitor that also records temps and other conditions).  For that reason alone I'd want to buy your car back (again, if I were their engineers).  Just based on a career of troubleshooting computer problems, it's having one solid case that you can work on that could go a long way towards solving ALL these issues (then again, what do I understand about auto maker politics -- it just seems to me they could save a ton of money in the long run if they had four or five cars like yours they could set up in test cases to get it solved once and for all).

I don't think Ford wants to talk to me any more.  I'm pretty sure they just want me to go away.  (Not talking about my dealer, they're great; I mean Ford corporate).  I posted it here in the hopes that maybe someone from Ford Engineering is reading this thread and could use the data point for their benefit.

Yes, my car sits outside - but it seemed from what I had read on here that more people with this problem had their cars parked in garages than outside.  The challenge is that the car basically needs to be driven and monitored constantly, and the problem might appear tomorrow or might not appear for 3-6 months -- that's how intermittent it is.  I'm also a computer engineer, so I know this type of intermittent problem is horribly annoying as the engineer trying to solve the problem, and which is also probably why we haven't yet seen a definitive fix.

Interestingly, after dying today and having it jumped, I noticed an added draw on the "accessory" battery draw gauge that I setup on MyView for about an hour of driving (the 120v must've been recharging the 12v), and tonight the voltage monitor is sitting at 13.0 - higher than it has been in "sleep" state since I started monitoring it in late June.

Anyway, Happy C-Max'ing, everyone, I'll post more later if I have more data or come to a resolution.

My battery was replaced by the dealer on May 8, 2014 for the second time, after the battery tested bad (first time was October, 2013).  Ford then sent one of their field engineers to review and service the car on May 29.  This morning, my battery was dead again.  Less than two months since the battery was replaced.

I have a voltage meter plugged into the 12v jack in the trunk compartment.  I've been checking it every morning before I unlock the car, so it reflects the accurate "sleep" state voltage.  For the past week, it has been 12.5v, which according to this chart, means roughly 90% charge.  I also, fortunately, checked it last night when I took the trash out around 1am, and it was still at 12.5v.  This morning at 9:30am, the car was dead, and the voltmeter read 5.2v.  I had Ford Roadside Assistance come and jump the car.

Between May 8 and today I've had no problems.  But, for some reason, overnight, *poof* the battery discharged.  I have no explanation.  It rained *hard* on Monday, but nothing since, and I haven't had the car washed recently, so I don't see how water intrusion could be a problem in this case.  The car was locked this morning, so it wasn't that I left it unlocked.  Ford has applied all of the software updates (at least up to May 29, including the DC-to-DC converter update), so it's current.  I'm not totally up to speed on all the latest dead battery news, but those are all of the potential causes I'm aware of.

I don't see how charging the battery every 3 months would do anything, given that it died in less than two months on a brand new battery.  Ford has had my car for about two weeks over the past year to try and diagnose it, and I have an ammeter that I've used as well, clamped around the negative cable coming off of the battery, to perform my own parasitic load test - there is no parasitic load under normal circumstances.  There's clearly something that triggers a problem under very specific, rare, occasions.  Or, perhaps, the 12v battery is just under-engineered.  Coincidentally, I've noticed all of my "dead car" issues have occurred when the overnight temperature was in the upper 50's, so perhaps that's also a clue.

I dunno.  I sincerely hope Ford can solve the problem soon, because yeah this is an amazing car, but this battery problem sucks.

Finally got my first 600+ mile tank again after a very long winter of 450-500mi tanks.  Looks like it's time to work on that 800.

You mentioned that the car had been sitting for a few days. Sounds like one of those odd things that could happen when the 12-volt battery is partially discharged. At least it didn't strand you with a dead battery!

Well that was prescient... 4 days later and *poof* dead battery.  So if anyone else experiences this, watch your battery.

Time to add my name to the list of people who have experienced battery failure after the having the recall service done.  Whoever mentioned the battery in my steering wheel controls thread was right.

Brought my car home last night, all was fine.  Went to the car this morning, doors wouldn't unlock, battery completely dead.  No clue what could've caused it.  In the past I've been away for several weeks and all has been fine when I got home, but yesterday I drove it plenty.  The only think I can think of is that the last time my battery died, the temperatures at night were very close to what they currently are.  It was fine all winter with freezing temps, but last fall it was around the same.

I didn't buy one of those jumpers drdiesel mentioned last time b/c, quite honestly, I don't think it's something I should have to buy and lug around with me simply because there's an underlying problem with my car.  The car should just work.

Sad thing is how much I otherwise love this car, because damn this is annoying.

Roadside assistance is on its way now, then I'm going to drop it at the dealer.  At least this time they agreed to give me a loaner.

Ashley I'll PM you momentarily, although I'm not sure what you'll be able to do to help.

Well, now it's back to normal.  Go figure.

I tried searching but couldn't find anything either.  Thanks, though.

After being away for a couple days, I went out to my C-Max this morning... I decided i wanted to check my trip 1 and discovered the down button on the left steering wheel control no longer functions - instead of making the display go down, it instead goes left.  Then, later during my trip, the down and up buttons became reversed.  It just doesn't seem to operate reliably.

Has anyone else experienced this?  I'll have to take it into the dealer, but I've had it in for service enough and I really don't want to have to go back there again.