Recurrence of battery failure

[jdbob]

I know in another thread the drdiesel said a usb port appeared responsible for draining his battery -- I wonder if that could be a common issue among others, or if it's again just an intermittent, and sometimes errant system/module simply hanging and not shutting down properly after vehicle shutdown.

 

Of course people leave stuff plugged into the USB port everyday without problem. I always have a USB flash drive with music there all the time. Knowing that the infotainment computer (which powers those USB ports) is running Microsoft software, I also made up a plug with a LED that sticks out a bit from the center console so I can tell if the computer shut off or not. I check it just before I leave my garage and it did get stuck on one time. I don't know what it was doing but after 5 minutes of waiting I got bored (plus it was winter) and opened the door and closed it again. At that point it shut down like it normally does a half minute or so after closing the door. If it wasn't so bloody cold I would have left it for longer to see what happens.

[Kelleytoons]

A USB port only supplies 500 miliamps -- to put this in perspective, a cigarette lighter is usually fused at 8 amps (some at 10) which is at least 40 times this much power.

 

Another way of looking at it is even if that USB device was drawing power (and such a drive will not do so continuously even in use -- usually even during read/write operations it's only working about 5% of the time) you could run it 40 or 50 times as long as something from your normal 12 volts without drawing down your battery.  Or, to put a cap on it, it would take about three days of such use before it would affect any battery significantly.

 

I would *never* be concerned about the USB ports being an issue.

[jdbob]

It's probably not what is plugged into the USB port that is the problem but the computer that supplies the power to those USB ports, in this case the infotainment computer. If the USB ports have power that means the infotainment computer is on. And that computer is networked to other computers so maybe they get left on as well. Thats the problem with intermittent faults, it's very difficult to figure out what is going on when it happens and difficult to reproduce if it's taken to the dealer.  

[RobMax]

 

 

Of course people leave stuff plugged into the USB port everyday without problem. I always have a USB flash drive with music there all the time. Knowing that the infotainment computer (which powers those USB ports) is running Microsoft software, I also made up a plug with a LED that sticks out a bit from the center console so I can tell if the computer shut off or not. I check it just before I leave my garage and it did get stuck on one time. I don't know what it was doing but after 5 minutes of waiting I got bored (plus it was winter) and opened the door and closed it again. At that point it shut down like it normally does a half minute or so after closing the door. If it wasn't so bloody cold I would have left it for longer to see what happens.

 

 

 

A USB port only supplies 500 miliamps -- to put this in perspective, a cigarette lighter is usually fused at 8 amps (some at 10) which is at least 40 times this much power.

 

Another way of looking at it is even if that USB device was drawing power (and such a drive will not do so continuously even in use -- usually even during read/write operations it's only working about 5% of the time) you could run it 40 or 50 times as long as something from your normal 12 volts without drawing down your battery.  Or, to put a cap on it, it would take about three days of such use before it would affect any battery significantly.

 

I would *never* be concerned about the USB ports being an issue.

 

While a usb port supplies a max of .5A, whatever might be controlling that port and other functions "behind the scenes" is likely drawing much more power. Something like that could explain drdiesel's large battery drain. Just a thought. jdbob mentions Microsoft software running everything there -- that explains the problem right there!  :)

We should expect "C-Max Service Pack 3" to fix all these potential problems when it gets released.  :woohoo:

Whatever the case, it's an interesting problem with some potential fixes to fix some potential problems. I'm not too worried either way since I have this forum and its awesome members. Still though, I need to drop my Max off at the dealership to program the 2nd key they lost, so I'll request they throw it on their good charger too.

[drdiesel1]

Sorry, I wasn't clear enough.  I wasn't comparing Audi to C-max, I was simply pointing out that starting batteries generally last a long time without trickle charging every 3 or 6 months.  And if it was beneficial, don't you think it would have become "established wisdom" --i.e. part of service manuals, battery experts maintanence suggestions, tune-up schedules etc.  Why not?   

 

I'm glad you quoted C-max Traveller:

" 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"

 

So we have clear evidence that a) the C-max charged the battery correctly and b)it still went dead.  I'm no Sherlock Holmes, but that would suggest this problem has nothing to do with SOC.

 

Again, just one man's opinion, and while charging your battery every 3 or 6 months won't do any harm.  It won't help much either.

Keep telling yourself it won't help :victory: If you think a static voltage  reading is proof of a batteries charge state,

you need to rethink that one. You're readout proves nada. You need to test the battery before making statements

that have ZERO foundation of any problems with your 12V system problem. You also need to verify the very likely hood

of a parasitic draw on that battery. You can't just claim it was properly charged without getting proper data from the battery.

 

You can ignore any advice you like, but you can't ignore that fact you don't understand what's really wrong

with your car and why this is happening without proper diagnosis of the problem. Otherwise, it's wild guess time,

as you so clearly are happy to report as knowledge of the cause of failure. All it really does is make it more confusing

for anyone reading this post. You're contributing to internet myths and DIY misinformation without any proof.

Edited August 28, 2014 by drdiesel1

[plus 3 golfer]

If one wants to know SOC of the 12 V battery, I suggest buying a hydrometer and measuring the specific gravity of each cell as an indication of SOC of each cell.  In normal driving there really isn't much benefit in charging a battery externally.   But, if one makes many short trips it is good practice to charge the battery periodically externally or to drive the vehicle on a longer trip say 30+ minutes every week or so to charge the battery back to near 100% SOC..  This is assuming that the battery is not "dead" (very low SOC).

 

Our other vehicle is used for very short trips (one mile to the golf course, one mile to the fitness center, 2 1/2 miles to supermarket) as we use the C-Max for our normal 12+ mile trips.  So after 3-4 weeks of such short trips (maybe 100+ starts), it's very noticeable that the engine cranks slower on start up.  So, I make a significantly longer trip or put the charger on the battery periodically.  

 

So, the issue with the C-Max (especially on shorter trips) really isn't much different than my other car except one really can't determine  when the 12 V C-Max battery is losing and not replenishing charge (like slower cranking on my other vehicle). The C-Max starts or doesn't start (no cranking). Add to this a possible parasitic load and significantly lower 12 V battery capacity of the C-max and one can see why the C-Max might not start because of a low SOC 12 V battery.  IIRC, one of the "fixes" for the 12 V battery issue was to increase the charging voltage of the DC/DC converter slightly thereby increasing the charging current.

 

Having said the above, this does not get Ford off the hook.  Ford could monitor SOC of the 12 volt battery by coulomb counting and voltage readings as a way to estimate SOC of the 12 V battery and keep the DC/DC converter active to charge the 12 V battery after the car is off for a period of time and also alarm for abnormal conditions.  Of course since this battery issue apparently affects a small portion of its C-Max fleet, Ford likely won't implement such. 

[Adrian_L]

Sorry Diesel, I haven't been able to take anything you have written seriously since that bizarre rant against Toyota.

 

Something I learned a long time ago--the thoughtful rarely use overgeneralizations.   "All Toyotas are crap!"  "Ford mechanics are just parts replacers!".  These are not observations of the careful mind.  These are observations of the cab driver and the barber who have all the answers and could fix the country if they weren't too busy cutting hair and driving cabs.

 

Let's look at the Toyota rant:  These are cars that top customer satisfactions surveys year after year.  My mother-in-law has a '98 Corolla---never had a problem.  My father-in-law has a '99 Camry--never had a problem.  My brother has a Lexus---all he does is change the oil.  I'm sure there are alot of folks on the forum with dead batteries who would love to have Toyota's reliability.  I think they're boring cars, but that is different than saying they are all POS.  When I had an Audi, two mechanics (no make that 3) told me they hated German cars and told their families to buy Honda or Toyota. 

 

At no time did I ever report that I knew the cause of the 12v battery failure.  If you feel so strongly, take your trickle charger to Michigan.  I'm sure the Engineers would love to hear your advice.

[Adrian_L]

If one wants to know SOC of the 12 V battery, I suggest buying a hydrometer and measuring the specific gravity of each cell as an indication of SOC of each cell.  In normal driving there really isn't much benefit in charging a battery externally.   But, if one makes many short trips it is good practice to charge the battery periodically externally or to drive the vehicle on a longer trip say 30+ minutes every week or so to charge the battery back to near 100% SOC..  This is assuming that the battery is not "dead" (very low SOC).

 

Our other vehicle is used for very short trips (one mile to the golf course, one mile to the fitness center, 2 1/2 miles to supermarket) as we use the C-Max for our normal 12+ mile trips.  So after 3-4 weeks of such short trips (maybe 100+ starts), it's very noticeable that the engine cranks slower on start up.  So, I make a significantly longer trip or put the charger on the battery periodically.  

 

So, the issue with the C-Max (especially on shorter trips) really isn't much different than my other car except one really can't determine  when the 12 V C-Max battery is losing and not replenishing charge (like slower cranking on my other vehicle). The C-Max starts or doesn't start (no cranking). Add to this a possible parasitic load and significantly lower 12 V battery capacity of the C-max and one can see why the C-Max might not start because of a low SOC 12 V battery.  IIRC, one of the "fixes" for the 12 V battery issue was to increase the charging voltage of the DC/DC converter slightly thereby increasing the charging current.

 

Having said the above, this does not get Ford off the hook.  Ford could monitor SOC of the 12 volt battery by coulomb counting and voltage readings as a way to estimate SOC of the 12 V battery and keep the DC/DC converter active to charge the 12 V battery after the car is off for a period of time and also alarm for abnormal conditions.  Of course since this battery issue apparently affects a small portion of its C-Max fleet, Ford likely won't implement such. 

 

Just so we're clear.  You're saying that a multimeter reading (after the car has been idle for say 6 hours) of the battery is pointless and when C-max Traveller checked his voltage at 1 a.m.  and it was 12.6 that told him nothing?

 

I'm not trying to start an argument or anything, but there are probably 100 or more marine/rv/auto dedicated websites putting out this misinformation.  They must be stopped.

[wab]

Sorry Diesel, I haven't been able to take anything you have written seriously since that bizarre rant against Toyota.

 

Something I learned a long time ago--the thoughtful rarely use overgeneralizations.   "All Toyotas are crap!"  "Ford mechanics are just parts replacers!".  These are not observations of the careful mind.  These are observations of the cab driver and the barber who have all the answers and could fix the country if they weren't too busy cutting hair and driving cabs.

 

Let's look at the Toyota rant:  These are cars that top customer satisfactions surveys year after year.  My mother-in-law has a '98 Corolla---never had a problem.  My father-in-law has a '99 Camry--never had a problem.  My brother has a Lexus---all he does is change the oil.  I'm sure there are alot of folks on the forum with dead batteries who would love to have Toyota's reliability.  I think they're boring cars, but that is different than saying they are all POS.  When I had an Audi, two mechanics (no make that 3) told me they hated German cars and told their families to buy Honda or Toyota. 

 

At no time did I ever report that I knew the cause of the 12v battery failure.  If you feel so strongly, take your trickle charger to Michigan.  I'm sure the Engineers would love to hear your advice.

 

Updated my Signature, Thanks

 

[Kelleytoons]

Well, I *never* make absolute statements.

[DaveofDurham]

Well, I *never* make absolute statements.

And you never say never

[Kelleytoons]

Well, there are two kinds of people -- those who divide folks into two kinds of people, and those who don't.  I fall into neither group.

[plus 3 golfer]

Just so we're clear.  You're saying that a multimeter reading (after the car has been idle for say 6 hours) of the battery is pointless and when C-max Traveller checked his voltage at 1 a.m.  and it was 12.6 that told him nothing?

 

I'm not trying to start an argument or anything, but there are probably 100 or more marine/rv/auto dedicated websites putting out this misinformation.  They must be stopped.

Nope, I never said it was pointless  But, most likely don't understand what the voltage reading "really indicates" and are simply giving a quick test to see if the battery may be the cause of a no start due to a low voltage reading (SOC).   Most aren't going to have the proper test equipment to test a battery fully like a shop will have.  So, using a multimeter to measure voltage (including when the car is being charged), driving the car for some distance to charge the battery back up (or buying a "home" charger), and then testing with a hydrometer will give one a very good idea whether the battery cells can hold the charge. 

 

The problem is that SOC indicated by voltage measurement doesn't tell you whether the battery is "good" and can provide enough current / voltage when load is applied. But, if your battery is "good", the voltage method is a good indication of the SOC and since the battery is "good" but has a low indicated SOC, the battery can be recharged.  Now, if your battery is "bad" (one cell limits current in the series of cells), a voltage reading (with minimal load on the battery) will likely indicate typical voltage. But when the "bad" battery is placed under load, the battery current will be limited to the current of the "weakest" cell and voltage could then drop below a starting threshold.

 

So, if one wants to know the health of the battery one should check each cell for its specific gravity to see if any cell readings are abnormal.  If one has a low voltage reading indicating a low SOC, they should charge the battery and then check each cell with a hydrometer to make sure the cells are okay.  Better yet, one can take the car to a shop that has the proper equipment to test the battery to see if the battery is "good" or "bad".

[kostby]

Sorry Diesel, I haven't been able to take anything you have written seriously since that bizarre rant against Toyota.

 

For forum members who haven't explored the 'Your Profile' settings button next to your forum username, there is a Manage Ignore Prefs setting, so you can mute the posts, signatures, messages, or all three of other members.

[Adrian_L]

That's a bit extreme. Besides, content would be diminished by about 80% ;)

 

I have no problem with my statements or ideas being challenged, refuted or attacked. But no member needs to have a hissy fit every time someone disagrees with him.

[salman]

There is pretty clear evidence that the 12 volt problems in the CMax are not due to a problem with the charging routine nor to a problem with the batteries.

 

There is positive evidence that there are problems with electrical connectors (on examination they show water and corrosion), and circumstantial evidence that repairing the connections ends the 12 volt problems (5 months trouble free for me, but time will tell).

 

On the other hand, my Honda Accord has battery problems. I've had to change the battery four times!!! Of course, it is a 1995, but the rest of it seems like it will last forever. Obviously made by people who did not understand the fundamental value of planned obsolescence.

[drdiesel1]

Sorry Diesel, I haven't been able to take anything you have written seriously since that bizarre rant against Toyota.

 

Something I learned a long time ago--the thoughtful rarely use overgeneralizations.   "All Toyotas are crap!"  "Ford mechanics are just parts replacers!".  These are not observations of the careful mind.  These are observations of the cab driver and the barber who have all the answers and could fix the country if they weren't too busy cutting hair and driving cabs.

 

Let's look at the Toyota rant:  These are cars that top customer satisfactions surveys year after year.  My mother-in-law has a '98 Corolla---never had a problem.  My father-in-law has a '99 Camry--never had a problem.  My brother has a Lexus---all he does is change the oil.  I'm sure there are alot of folks on the forum with dead batteries who would love to have Toyota's reliability.  I think they're boring cars, but that is different than saying they are all POS.  When I had an Audi, two mechanics (no make that 3) told me they hated German cars and told their families to buy Honda or Toyota. 

 

At no time did I ever report that I knew the cause of the 12v battery failure. ***mod edited stop the personal attack crap****

Unfortunately I don't care about your inability to understand anything or what, I post.

You clearly are unaware and blabber on about things you know nothing about.  My advice isn't

for you, so just carry on with the clueless ramblings and wild guessing about what's wrong with your car.

***mod edited stop the personal attack crap**** :thumbsup:

 

 

@drdiesel1 @adrianL - you know, take this personal attack crap to the PM, I don't want to read it and neither do other posters. We have a serious issue here and if you can't CONTRIBUTE positively - shut the f*ck up.

 

DD - this is the last warning I am going to give you. You've been banzored before and most part, you've behaved since returning but theres only so much I will tolerate and you've crossed the line with your personal attack. So you now have an official warning. Next time, you're on the perma-ban bus leaving town.

 

Please think through your words before clicking on Post, you know better.

Edited August 29, 2014 by Jus-A-CMax

[CMax-Traveler]

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.

Edited August 29, 2014 by CMax-Traveler

[drdiesel1]

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

[wab]

For forum members who haven't explored the 'Your Profile' settings button next to your forum username, there is a Manage Ignore Prefs setting, so you can mute the posts, signatures, messages, or all three of other members.

 

Here's another option.

 

Copied from.

http://www.bullyonline.org/related/cyber.htm

"The Number One rule for dealing with this type of behaviour is: don't respond, don't interact and don't engage. This is not as easy to do as it sounds. It's a natural response to want to defend yourself, and to put the person right. However, never argue with a serial bully; it's not a mature adult discussion, but like dealing with a child or immature teenager; whilst the serial bully may be an adult on the outside, on the inside they are like a child who's never grown up - and probably never will. Serial bullies and harassers often have disordered thinking patterns and do not share the same thoughts or values as you."

Edited August 29, 2014 by wab

[Jus-A-CMax]

...ok, side show is over, concerned parties have been warned. Lets get back to the problem diagnosis and solving.

Edited August 29, 2014 by Jus-A-CMax

[CMax-Traveler]

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

[RobMax]

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.

 

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.

 

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? 

[CMax-Traveler]

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.

Edited August 29, 2014 by CMax-Traveler

[Adrian_L]

There is pretty clear evidence that the 12 volt problems in the CMax are not due to a problem with the charging routine nor to a problem with the batteries.

 

There is positive evidence that there are problems with electrical connectors (on examination they show water and corrosion), and circumstantial evidence that repairing the connections ends the 12 volt problems (5 months trouble free for me, but time will tell).

 

On the other hand, my Honda Accord has battery problems. I've had to change the battery four times!!! Of course, it is a 1995, but the rest of it seems like it will last forever. Obviously made by people who did not understand the fundamental value of planned obsolescence.

 

...ok, side show is over, concerned parties have been warned. Lets get back to the problem diagnosis and solving.

 

My apologies, Jus and company.  I'm sure the members could have done without this negativity in which I was a key player.   I (like Salman and others) feel strongly that based on annecdotal evidence the 12 volt problem is (probably) not directly related to a charging issue and I felt compelled to say so.  

 

Greatly appreciated C-max Traveller's input above.  

 

I have been careful to keep my statements free of personal insults and I intend to keep it that way.    

Edited August 29, 2014 by Adrian_L