[Three_thirty_I]

So this is an annoying one. I have been battling with a dying battery issue for a bit more than 2 years now, and last year I got fed-up with the battery barely being able to last a week between drives. Refer to this thread to see more about that: Less than 2 year old battery dying?!

In summary though, 2 and half years ago I noticed that the car's original battery was slowly getting weak and especially during the winter months. I invested in a good Ctek charger to see if I could keep it going and recondition it, but ultimately it being 8 years old needed to be replaced. So I fitted a new BMW OEM battery of the same capacity and had it registered etc. But this new battery didn't seem as eager as I would have expected and soon I started having problems where the battery would be completely drained to the point where the car had to be opened with the key manually (not good for the lock). When this happened a week after a good drive, I decided it was time to have the car properly tested for parasitic draw, charge rate, and of the battery itself. It was found that the battery did have a dead cell, so it was discharging itself. There was no parasitic draw and the charge rate was fine, so luckily I was able to get the BMW dealer to replace the 2 year old battery. But some months later, the car was sitting for a week and with a dead battery. Admittedly there are times where the car does not get driven a lot, but this is also the case with the other vehicles that I own, so if they are fine then this should be fine too, especially for a week when the others can and do often last 2, 3 weeks of standing.

Fast forward to right now - the car last drove literally a week ago, so last Thursday and all was fine, I even checked the battery voltage and all was fine. Wanted to use it this afternoon and when I tried to unlock it did nothing, but the alarm light was still blinking. I tried the spare set, same. So I unlocked manually and immediately heard the car try to come to life, fuel pump wasn't not happy, so opened the bonnet and put it on charge immediately. Of course the trip meter lost it's memory and with the battery being so depleted it showed the normal ABS and other warning lights. It takes a while before you can reset the TPMS which is what causes these warning lights. But strangely it remembers my average fuel consumption.

My suspicion is that the driver's door lock (or possibly one of the others) has become faulty and is not allowing the car to enter sleep mode intermittently. And interestingly, the last motorplan covered service back in 2012, they had replaced the driver's door lock - I didn't have any issues, so they must have had a reason to replace it. I did have a CAS fault that caused the steering lock to not always unlock, but this was fixed with a software update back then. So my plan now is to take it for a drive once the battery is fully charged, then park it in my garage but with the alarm not set, and leave it for a week while monitoring the battery voltage. Then drive it (charge the battery if necessary) and repeat this test. If it behaves, then it goes back to the place that tested it before, and let them see if they can replicate the problem while testing for parasitic draw.

That's all that I can think is causing the problem at this stage. I even phoned the previous (original) owner to ask them if they had a GPS tracker installed when they owned the car, but apparently not, so can rule that out as a possible culprit.

Any advice or suggestions though would be most welcome.

[Three_thirty_I]

Update:

Battery was showing as fully charged early this morning, so a bit later I took it off charge and the plan is to leave it for the moment and just monitor the voltage drop across the jumper points in the engine bay (where I obviously charged from). All windows close, driver's door unlocked and of the bonnet open. I wonder if it is necessary to "fox" the system by putting something in place to press and hold the bonnet switch down. But I don't think it would make a difference unless I am mistaken. Don't know if the car goes into proper sleep mode, but I think if the locking mechanism is intermittently causing a power drain, then having it like this should still draw less power? Many people never bother to lock their cars when parked in their garages and don't sit with drained batteries.

So far the battery is now sitting on 13.12v from 13.36v a few hours ago. It should hopefully settle around the upper 12v range and mostly stay like that. I will have to drive it over the weekend though and will continue monitoring the battery.

But if I wanted to fast forward this, assuming that one of the door locks was to blame, could they be tested to see if there was a problem, and identify which lock was faulty? Ultimately something is draining the battery sometimes, and it is very possible that it is one of these locks, so if that is the case, then problem solved.

Update 1:

Battery now sitting on 12.98v a little over 9 hours later...

Update 2:

Battery now sitting on 12.71v 25 hours after fully charged - so lost around 0.41v since Friday around the same time...

Update 3:

Battery now sitting on 12.44v 52 hours after fully charged - so lost around 0.68v since Friday around the same time...

[Three_thirty_I]

Was hoping that there would have be some advice or assistance, but anyway, I am still somewhat convinced that this problem relates to a faulty door lock actuator. I am hoping that it is easy to test the lock actuators, but will have to make some enquiries.

I have been updating the post above with the voltage drop over the last two days with the car parked and closed, but not locked and the bonnet open. So I am not sure if the drop in voltage that I have noticed is acceptable for the car parked and closed in this configuration, but it seems fair so far. Since the battery was fully charged it had lost about 0.68v (13.12v to 12.44v), and this spanned a period of just over 2 days (about 52 hours).

When I took this last voltage reading, I decided to take the car for a good drive (about 50 or so km) on mostly open road with no stops, returned and checked the voltage after switching the engine off. It showed 13.11v - with the engine running it had shown ~14.35v. Some hours later I checked the voltage again, showed 12.71v. I then had to close the driver's window which meant turning the ignition on, and checked something on the service info that I wanted to see, so in total the ignition was active for a few minutes. The voltage had now dropped to 12.55v but climbed to 12.56v immediately - checked again an hour later and it was back up to 12.71v, so it recovers.

All I can do for the moment is keep an eye on it while having the car parked either locked or unlocked as I have done so far and see if I notice a distinct drop in voltage. But ultimately I am going to have to take the car in and have it properly tested, hoping that if it is a faulty door lock that it will be easy to verify.

[PichaDis11]

Can you have the car scanned for codes with good BMW scanner?

Also when my car fully goes to sleep. The led showing for the gear selector goes off last. This includes the start/stop button too. Try to use this to see if it's truly not entering sleep. Not saying it would be a direct relation to the car fully bring sleep though. Just another thing to look at.

[Three_thirty_I]

Originally Posted by PichaDis11

Can you have the car scanned for codes with good BMW scanner?

Also when my car fully goes to sleep. The led showing for the gear selector goes off last. This includes the start/stop button too. Try to use this to see if it's truly not entering sleep. Not saying it would be a direct relation to the car fully bring sleep though. Just another thing to look at.

The car was scanned before this new battery was fitted. They checked for error codes and then tested the electrical system thoroughly. It did go into sleep mode and the current draw was spot on. But if this is an intermittent fault as I suspect, they will then need to repeat this test until they can see that something is preventing the car from going to sleep. I am just hoping that if it is suspected that it could be a faulty door lock mechanism that they can test it somehow.

The battery voltage now is 12.68v which is almost as it was this time yesterday. So with the car unlocked it seems to be fine for now. I am going to have continue to keep an eye on it and maybe leave it for longer this time. Something must be draining the battery in order for it to become completely discharged, so it has to be possible to find the cause. Was just hoping that someone here that may have gone down this road before would share their experiences.

[BashShah]

Is there someone in the house playing with the Keyfob?
These Bundle of Joys can be real Devils also.

Bash Shah
Sutton Premier Realty

[Three_thirty_I]

Originally Posted by DarkNemesis

Is there someone in the house playing with the Keyfob?
These Bundle of Joys can be real Devils also.

Bash Shah
Sutton Premier Realty

LOL, no, not at this stage. And should have also mentioned from the start - this is not comfort access, just the normal keyfob that charges when in the ignition and does not affect the car if it is too close to the it. It is literally parked, locked, and left untouched with the keys left alone hanging on our key holder.

While I am replying, may as well indicate that the battery voltage is now sitting on 12.58v - the car has not moved since Sunday when I drove it last, all doors/windows closed but the bonnet open and the alarm not set. Have not opened the car or done anything since other than keep an eye on the battery voltage.

[Three_thirty_I]

Update:

So the car was last driven last Sunday, so 7 days ago plus probably another 8-9 hours to be exact. The voltage is sitting at present at 12.46v. So definitely seems to be holding a decent charge in the current parked configuration. I will take it for a drive within the next day or so, but I think it is fair to say that there can only be something that is draining the battery when the car is locked. I would have to repeat this test but with the car locked and see if I can observe a distinct and quicker drop in resting voltage. I would still like to know if it is suspected that there is a problem with one of the door locks that the culprit can be easily detected/tested. But that's for another day.

[Three_thirty_I]

Update:

So since this thread was started, I have been monitoring the battery voltage daily, and have been using the car at least once a week with a few decent medium open road trips. Still definitely less driving that would be ideal, but enough to keep a battery alive.

This past Sunday afternoon I decided to use the car for a shopping errand, so before I went to the shopping mall I took it for a long enough drive to get the engine warm and to allow the battery to get some charge at least. I then returned home taking a slightly longer route, but still a reasonably shorter run than usual. But with that said, much the same sort of drives that my other cars are perfectly happy to do without any battery issues.

I park the car back in my garage and as always I leave the driver's window down for a few hours before I lock the car. But for the past month or so (since I started this thread) I have not been locking the car at all when it's parked in the garage, instead I just close all windows and with the bonnet open leave the car unlocked while I monitor the battery.

The resting voltage straight after parking the car was a bit lower than I was expecting even with the typical drop from the electronics being awake still, so I checked again in an hour after the car was suppose to be in sleep mode. But the voltage was sitting around 12.50v, and a few hours later it was around 12.40v and seemingly dropping the whole time. Monday afternoon, and around 24 hrs later the voltage was sitting around 12.22v which is absolutely the lowest it's been since I have been monitoring. Over the weeks that I have been keeping an eye on the resting voltage, it seems to start from around 12.60v and slowly drop and settle around 12.40v, maybe dipping slightly below that as it reaches a full week of standing - not less than a day later!

So for the first time since I started this thread, I hooked up the Ctek charger to restore some life into this battery, and late Monday night it was fully charged. The resting voltage was 13.10v, lower than before when I charged it. So I again left the car and checked the voltage this afternoon. Freakin' thing was down to 12.56v! Now I am thinking I must be onto something here with the battery drain. I unlocked all doors, opened all windows, opened the boot, then closed everything again, set the alarm, unset and unlocked the driver's door - so basically cycled all locks and window mechanisms. I then checked the voltage an hour later, 12.71v!!! It has gained power, or rather, now has less power being drained off in this state of sleep mode.

At least now I know that I am onto something valid and that it is an intermittent problem, but this also means that leaving the car unlocked is not necessarily the temporary compromise solution, the battery voltage is always going to have to be monitored after parking the car, and this means that the bonnet will have to continue to be left open for the time being. Obviously I am going to eventually see if the fault can be traced, but how easy this is going to be, and how long it will take is another question...

Sorry for the long post, but had to include all the relevant information and experiences. And as always, am open to any advice or suggestions.

[EB89]

Just found this thread and read everything.

Man I think I'm in the same situation as you.

My battery is dieing intermittently, I have a CTEK5amp charger that I've used.

The only connection I can make it the battery dies mostly when the car is parked at my office, I can drive it in the morning fine but if I try to drive at lunch or when I leave work it's dead.

Probably happened 5 times now.

I can jump start it fine and it holds a charge, will be fine for a week or two then bam, dead.

I thought my phone might be too close and it was connecting? Something to do with me being at work, I don't know it doesn't make sense.

What makes you think it's your door?


I found this thread with the same problem I have

http://www.e90post.com/forums/showthread.php?t=1254340

Does your pump start up too? Mine does and runs for ages, maybe it intermittently starts up and drains the battery while I'm at work

[Three_thirty_I]

Originally Posted by EB89

Just found this thread and read everything.

Man I think I'm in the same situation as you.

My battery is dieing intermittently, I have a CTEK5amp charger that I've used.

The only connection I can make it the battery dies mostly when the car is parked at my office, I can drive it in the morning fine but if I try to drive at lunch or when I leave work it's dead.

Probably happened 5 times now.

I can jump start it fine and it holds a charge, will be fine for a week or two then bam, dead.

I thought my phone might be too close and it was connecting? Something to do with me being at work, I don't know it doesn't make sense.

What makes you think it's your door?


I found this thread with the same problem I have

http://www.e90post.com/forums/showthread.php?t=1254340

Does your pump start up too? Mine does and runs for ages, maybe it intermittently starts up and drains the battery while I'm at work

How old is your car's battery? Dying in such a short period of time is crazy! Mine luckily is not as bad as this. Have you checked for error codes, tested battery voltage and charge rate? I gather you have bluetooth for your phone, what about comfort access?

I don't have the water pump issue, I think that it's either a temperature sensor issue or some or other fault causing that. It would drain the battery in a fairly short time though. It's either thinking it needs to cool the engine post driving, as in the temp sensors are whacked.

Reason for thinking mine is door lock related is simply due to the fact that it seems to be a fairly common problem, and according my car's motorplan history BMW had replaced the driver's door lock back in early 2012. Not sure why, and if whatever they did has caused further problems, or they fitted a dud part. And then the other reason is that I was able to catch it in the act last week or so ago. After running some errands I noticed that the battery level was lower than usual, and not recovering. It had dropped voltage far lower than I had seen in over a month of daily monitoring. I then got my Ctek (same model as yours) connected and let it charge. When the battery was fully charged, the voltage was slightly lower that the voltage I saw when fully charged the last time. And then I noticed that it was dropping fairly quickly, in a day it had lost what would normally take almost a week. It was then that I thought I would try and see what happens if I cycle all the locks and window mechs. So every was opened, unlocked, locked, and then just the driver's door unlocked again. The voltage recovered and held with a very small drop for a week before I drove it again, that was the other day. So I just need to find out if there is a way to have the door locks tested to determine which one is at fault. Luckily it seems that my car's battery drain is a slightly slow process that takes a week or so to drain the battery, so for now I am just always keeping an eye on the battery. A bit painful, but better than getting to a car with a completely dead battery!

[EB89]

Battery prob came with the car and it's a 2011 model.
No errors codes from JB4 scan
Yeah Bluetooth and comfort access.

I found another thread where someone's water pump is staying on like mine does,
http://www.e90post.com/forums/showthread.php?t=1254158

[Three_thirty_I]

Originally Posted by EB89

Battery prob came with the car and it's a 2011 model.
No errors codes from JB4 scan
Yeah Bluetooth and comfort access.

I found another thread where someone's water pump is staying on like mine does,
http://www.e90post.com/forums/showthread.php?t=1254158

This is a weird one indeed. Saw the vid you posted on the other thread, seems very loud for the coolant pump - never heard mine sound like that.

[EB89]

Originally Posted by Three_thirty_I

This is a weird one indeed. Saw the vid you posted on the other thread, seems very loud for the coolant pump - never heard mine sound like that.

I confirmed its the coolant pump, I took the cap off the coolant tank and saw water spirting.

Last night I parked and the pump started, I let it go and this morning the battery was dead...

[Three_thirty_I]

Originally Posted by EB89

I confirmed its the coolant pump, I took the cap off the coolant tank and saw water spirting.

Last night I parked and the pump started, I let it go and this morning the battery was dead...

That's bizarre! What on earth is causing it to run when it shouldn't?

Had to use my car today, probably did about 80-90 km or so, battery was sitting on 12.44v before I left this morning, was 12.81v an hour after I parked the car for the day, now sitting at around 12.75v. So not too bad, it's just a problem when the battery drain issue creeps up again.

[EB89]

Originally Posted by Three_thirty_I

That's bizarre! What on earth is causing it to run when it shouldn't?

Had to use my car today, probably did about 80-90 km or so, battery was sitting on 12.44v before I left this morning, was 12.81v an hour after I parked the car for the day, now sitting at around 12.75v. So not too bad, it's just a problem when the battery drain issue creeps up again.

Well if you drive hard right before parking its normal to keep the coolant running to properly cool down the car.

I got a new CTEK 15AMP Charged yesterday afternoon, charged it all night.
When you test the voltage are you using a voltmeter or multi-meter? and when are you testing from, which points?

[Three_thirty_I]

Originally Posted by EB89

Well if you drive hard right before parking its normal to keep the coolant running to properly cool down the car.

I got a new CTEK 15AMP Charged yesterday afternoon, charged it all night.
When you test the voltage are you using a voltmeter or multi-meter? and when are you testing from, which points?

That makes sense, but even under an extreme case, it should run long enough to kill the battery, and typically for not much longer than a few minutes.

Using a multimeter on DC voltage, and I am taking my readings from the jumper points in the engine bay. So the bonnet is now always open while I am doing this. The proper way to do a load or drain test would be to connect the multimeter in series between the battery (negative terminal) and the car (negative cable). Then you can observe the current draw, but you have to be super careful because you can so easily fry your multimeter if too much current is being drawn. Also, you can only do this for testing purposes. So for me, the basic voltage test seems to be a good way to monitor the battery.

[Three_thirty_I]

I spoke to a BMW specialist today about this problem and he of course insisted that it may be a car tracker, but I can only trust that what the original and previous owner said about the car never having a tracker be true. In any event, I still think that what I have observed rules out the possibility of a tracker being the cause of the battery drain.

The other theory that he has is quite interesting, he suspects that it could be a faulty driver's side Window lifter switch box that is preventing the car from entering sleep mode. Apparently it can get damaged by water when washing the car and then rolling the windows down, or if the windows were tinted and some moisture from the tinting job got in. According to him, the only way to rule this out is to swap it out with another Window lifter switch box and see if it misbehaves. Other than that, says there is no real way to diagnosing which door lock (or other lock) could be to blame. Fun...

Any thoughts regarding this theory regarding the Window lifter switch being the possible cause?

[EB89]

FYI I just ended up getting a new battery, it hasnt been in long enough to know if it worked or not. I got it cheap so thought why not, rule it out.

[Three_thirty_I]

Hope this sorts your problem out!

[EB89]

Found my issue,

JB4 ISO battery drain with the water pump.

There is a fix from burger in this thread.

Do you have a JB4? And are you N55 ISO?

http://www.n54tech.com/forums/showthread.php?t=31842

I took my JB4 out completely and the car has been perfect.

[Three_thirty_I]

Originally Posted by EB89

Found my issue,

JB4 ISO battery drain with the water pump.

There is a fix from burger in this thread.

Do you have a JB4? And are you N55 ISO?

http://www.n54tech.com/forums/showthread.php?t=31842

I took my JB4 out completely and the car has been perfect.

No JB4, and my car is 100% stock. I have been continuing to monitor the battery all this time and it really seems to be a case of an intermittent drain caused by the electronics not completely entering sleep mode. In fact, I have caught it out at least once or twice waking up, at least that's what it seemed like. The car was sitting for probably a good hour or so, and I happened to be in the garage at that moment, heard the car make noises as if I had opened a door or something to that effect. So I will still have to figure this out, but at least I know how to work around it. A mech that I spoke to mentioned the switch box on the driver's door for the windows etc as being a possible culprit. Will have to check that out.