[Lucky13]

2007 E93 on the original battery but only 22,000 miles with very short drives. My Comfort Access on both keys with new batteries doesn't work ( touch feature) but can lock and unlock. Also my top gets stuck going up ( with engine running) and wondered if this could be related. No other indications of a bad battery and I've searched all the threads. Does this sound like a weak battery and could the top be related to this?

[NGEE]

Have you checked voltage at the battery? Short drives have been noted to decrease battery life.

Have you had the battery cable recall done yet? Probably not related, but it has caused some strange electrical issues.

[Lucky13]

Have not had the wires done because I just got my letter this week. Since they would have my car all day that's why I was considering having them put a new battery in at the same time if that is what is causing the Comfort Access or top problem.

[crimson335]

Just change your battery

[tofu-]

2007 is about a 5 year old battery. it wouldn't hurt to change it, especially since you aren't a frequent driver.

[teknic90]

Yeah. Battery for sure. Be sure to look up how to reset your battery in your ECU, or go to an indi. BTW, Interstate Battery makes a battery that's the exact same specs as the BMW one and comes with a better warranty.

[Lucky13]

I know I'm due for a battery since its 6 years old but wandered if that is causing the top problem and for sure the Comfort Access problem. I figured it has to be causing the Comfort Access problem but does the convertible top run totally off the battery even though the engine is running? A weak battery would explain the top if its running totally off the battery when engine is running.

[mr_milo]

Well I'm having some of the same types of issues with my comfort access and top. Thing is I have a 2011 that is almost exactly 2 years and one month old. I have been told that my driving profile doesn't allow the battery to fully charge. I was very confused by that statement since I had done the same commute for about four years prior to the BMW and NEVER had a problem in my Audi A4 which already had an old battery.

I started digging and found that the BMW's Brake Energy Regeneration system apparently only charges the battery "when you take your foot from the accelerator or apply the brake", therefore even if you are driving the car it may not be charging the battery!

They even acknowledged that "today's vehicles require much more electrical energy than older models, due to the much wider array of electric and electronic on-board comfort and safety systems", yet they think allowing the generator to only be active at certain times somehow makes good sense????

Needless to say I'm disappointed in BMW.

P.S. My commute is driving 9.7 miles, about 21 minutes with a mix of city streets and freeway, each day to and from work (about 19.4 miles / 42 minutes a day total). I find it had to believe this isn't long enough since my Audi handled it without issue and my wife's commute in her Honda CRV is only an extra 1-2 miles. The CRV is a 2009 with it's original battery.

[fun2drive]

News Item
This isn't your old BMW or Audi. I assure you if you are in the short driving cycle your battery has most likely been killed or soon will be. The charging system in this car is ultra complex. I am an EE by training and this charging system doesn't just do alternator to voltage regulator then back off once the battery reseaches sufficient charge. No-no this has the intelligent battery sensor (IBS) which in and of itself is a microprocessor with sensors to measure the temperature of the battery itself, charge rate, cycles of use,cable temperatures (not kidding here). All of this goes to the DME for a State of Charge (SoC) and the DME tracks this which is called Statement of Health (SoH).

To say this is over engineered to improve battery life by maybe 15% is an understatement.

Main point
Can this issue with your battery cause the top to stop in cycle?
I don't know but our alternator on the 335 is a 180A alternator. I think it is possible.

How would you check this?
Do not rely on BMW here for your 2007 but go to a part store that has a load tester. This is nothing more than a bank of resistors that help load the battery down similar to loading the battery as you would with your top operation. If it fails the test your battery is toast.

For the 2011 I would let BMW do this and expect a report back that you are abusing the charging system by short use (it is actually in the manual about the battery insufficient charging with short trips). I would argue with your SA that they should replace the battery. You will get this done once but after that it is your issue.

Comfort Access?
I don't know. If you are talking about touching the door to lock and unlock I would say no. If you are talking about opening the top using the CA I would say possible for the reasons stated above.

Solutions
First LOCK YOUR CAR
No matter if in the garage or where ever locking the car puts the DME to sleep (but not the IBS by the way) and will reduce the milliamp load (which is killing your battery) by the DME not cycling on every 4 hours to check the health of the car.

Second
Buy either a Deltran Battery Tender (even a junior battery tender works fine) or a CTEK intelligent battery charger and use it when you don't drive the car. Say you are not planning to drive the car for a couple days use the charger.
You can install the wiring cable to the jump posts in the front of the car permanetly or just use the clips and leave them attached. I have done both for well over 10 years and it works very well.
This will help keep your battery topped off all the time and the short trips will not cause issues because you will keep it maintained.
My E93 was the 2nd Euro delivery in Apr 2007 (Mar 2007 manufacturer) and my battery is still fine after 6 years because of the battery tenders (Deltran or CTEK take your pick both are very good).

My battery is a 900AH AGM sealed battery by the way which is what yours should be as well unless BMW changed the batteries to another AH.

Hope this helps and please report back what you discover as we try to help as best we can but we don't always hit the mark. We all learn by your reports...

[WULFFZA]

Originally Posted by fun2drive

News Item
This isn't your old BMW or Audi.

Solutions
First LOCK YOUR CAR
No matter if in the garage or where ever locking the car puts the DME to sleep (but not the IBS by the way) and will reduce the milliamp load (which is killing your battery) by the DME not cycling on every 4 hours to check the health of the car.

Second
Buy either a Deltran Battery Tender (even a junior battery tender works fine) or a CTEK intelligent battery charger and use it when you don't drive the car. Say you are not planning to drive the car for a couple days use the charger.
You can install the wiring cable to the jump posts in the front of the car permanetly or just use the clips and leave them attached. I have done both for well over 10 years and it works very well.
This will help keep your battery topped off all the time and the short trips will not cause issues because you will keep it maintained.
My E93 was the 2nd Euro delivery in Apr 2007 (Mar 2007 manufacturer) and my battery is still fine after 6 years because of the battery tenders (Deltran or CTEK take your pick both are very good).

My battery is a 900AH AGM sealed battery by the way which is what yours should be as well unless BMW changed the batteries to another AH.

Hope this helps and please report back what you discover as we try to help as best we can but we don't always hit the mark. We all learn by your reports...

What you said. Particularly the battery tender. I started using one a year ago and hook it up once a week or so. On my M5 the whole car behaved differently when it had spent time on the charger. Quicker starting, quicker nav boot up, smoother revving when cold etc. Don't know if everything was directly related to the voltage, but it felt that way.

I think after 5 years you are on borrowed time on a battery, on any car.

This is not a design flaw, its technological master piece that needs alot of juice. Sure they could put a bigger battery in it. Have you carried a battery lately? They're quite heavy.

[Lucky13]

Originally Posted by fun2drive

News Item
This isn't your old BMW or Audi. I assure you if you are in the short driving cycle your battery has most likely been killed or soon will be. The charging system in this car is ultra complex. I am an EE by training and this charging system doesn't just do alternator to voltage regulator then back off once the battery reseaches sufficient charge. No-no this has the intelligent battery sensor (IBS) which in and of itself is a microprocessor with sensors to measure the temperature of the battery itself, charge rate, cycles of use,cable temperatures (not kidding here). All of this goes to the DME for a State of Charge (SoC) and the DME tracks this which is called Statement of Health (SoH).

To say this is over engineered to improve battery life by maybe 15% is an understatement.

Main point
Can this issue with your battery cause the top to stop in cycle?
I don't know but our alternator on the 335 is a 180A alternator. I think it is possible.

How would you check this?
Do not rely on BMW here for your 2007 but go to a part store that has a load tester. This is nothing more than a bank of resistors that help load the battery down similar to loading the battery as you would with your top operation. If it fails the test your battery is toast.

For the 2011 I would let BMW do this and expect a report back that you are abusing the charging system by short use (it is actually in the manual about the battery insufficient charging with short trips). I would argue with your SA that they should replace the battery. You will get this done once but after that it is your issue.

Comfort Access?
I don't know. If you are talking about touching the door to lock and unlock I would say no. If you are talking about opening the top using the CA I would say possible for the reasons stated above.

Solutions
First LOCK YOUR CAR
No matter if in the garage or where ever locking the car puts the DME to sleep (but not the IBS by the way) and will reduce the milliamp load (which is killing your battery) by the DME not cycling on every 4 hours to check the health of the car.

Second
Buy either a Deltran Battery Tender (even a junior battery tender works fine) or a CTEK intelligent battery charger and use it when you don't drive the car. Say you are not planning to drive the car for a couple days use the charger.
You can install the wiring cable to the jump posts in the front of the car permanetly or just use the clips and leave them attached. I have done both for well over 10 years and it works very well.
This will help keep your battery topped off all the time and the short trips will not cause issues because you will keep it maintained.
My E93 was the 2nd Euro delivery in Apr 2007 (Mar 2007 manufacturer) and my battery is still fine after 6 years because of the battery tenders (Deltran or CTEK take your pick both are very good).

My battery is a 900AH AGM sealed battery by the way which is what yours should be as well unless BMW changed the batteries to another AH.

Hope this helps and please report back what you discover as we try to help as best we can but we don't always hit the mark. We all learn by your reports...

Unfortunately buying a new battery may not solve the two issues I am having and the only reason I am buying a new battery is to possibly solve these issues. I have no other electrical issues such as slow start, warnings or anything else.

[mr_milo]

Originally Posted by fun2drive

News Item
This isn't your old BMW or Audi. I assure you if you are in the short driving cycle your battery has most likely been killed or soon will be. The charging system in this car is ultra complex. I am an EE by training and this charging system doesn't just do alternator to voltage regulator then back off once the battery reseaches sufficient charge. No-no this has the intelligent battery sensor (IBS) which in and of itself is a microprocessor with sensors to measure the temperature of the battery itself, charge rate, cycles of use,cable temperatures (not kidding here). All of this goes to the DME for a State of Charge (SoC) and the DME tracks this which is called Statement of Health (SoH).

To say this is over engineered to improve battery life by maybe 15% is an understatement.

Main point
Can this issue with your battery cause the top to stop in cycle?
I don't know but our alternator on the 335 is a 180A alternator. I think it is possible.

How would you check this?
Do not rely on BMW here for your 2007 but go to a part store that has a load tester. This is nothing more than a bank of resistors that help load the battery down similar to loading the battery as you would with your top operation. If it fails the test your battery is toast.

For the 2011 I would let BMW do this and expect a report back that you are abusing the charging system by short use (it is actually in the manual about the battery insufficient charging with short trips). I would argue with your SA that they should replace the battery. You will get this done once but after that it is your issue.

Comfort Access?
I don't know. If you are talking about touching the door to lock and unlock I would say no. If you are talking about opening the top using the CA I would say possible for the reasons stated above.

Solutions
First LOCK YOUR CAR
No matter if in the garage or where ever locking the car puts the DME to sleep (but not the IBS by the way) and will reduce the milliamp load (which is killing your battery) by the DME not cycling on every 4 hours to check the health of the car.

Second
Buy either a Deltran Battery Tender (even a junior battery tender works fine) or a CTEK intelligent battery charger and use it when you don't drive the car. Say you are not planning to drive the car for a couple days use the charger.
You can install the wiring cable to the jump posts in the front of the car permanetly or just use the clips and leave them attached. I have done both for well over 10 years and it works very well.
This will help keep your battery topped off all the time and the short trips will not cause issues because you will keep it maintained.
My E93 was the 2nd Euro delivery in Apr 2007 (Mar 2007 manufacturer) and my battery is still fine after 6 years because of the battery tenders (Deltran or CTEK take your pick both are very good).

My battery is a 900AH AGM sealed battery by the way which is what yours should be as well unless BMW changed the batteries to another AH.

Hope this helps and please report back what you discover as we try to help as best we can but we don't always hit the mark. We all learn by your reports...

Thanks for the information but personally I think this is an over-engineering design flaw. I am an EE too and I've found a few over-engineered items which turn into design flaws on this car. It's basically too smart for itself and ends up being dumb when you try to use it. Now I totally understand why Jeremy Clarkson from Top Gear went off about the I-drive. I can also tell you for a fact that the Comfort Access & Opening the top with the fob will both turn off when the battery gets low. Problem is the functions just stop working and their is nothing telling you why they stopped working. Now that's an over-engineered design flaw. It's a shame too since it is a great driving car it just becomes not a great car to drive day to day.

My question would be this: How far must I drive to "maintain" the battery??? My commute is driving 9.7 miles each way to and from work. It takes me about 21 minutes each way with a mix of city streets and freeway for a total of about 19.4 miles / 42 minutes per day. I really don't consider this a "short" drive. I mean it's not like I'm driving to the corner store and back, but it seems it is too short for the BMW. Shouldn't I have been given a disclaimer about this when I bought the car?

The statements above basically tell me I need to sell my car since I can't use it for my driving needs without buying a new battery every two years or so. I didn't buy a "plug-in" and was honestly insulted when the SA told me "buy" a trickle charger and do so. If it needs it, shouldn't they be providing one? Personally I feel the same way about "locking" my convertible when the car is in my garage with the top down...... just another bit of dumbass over engineering in my book.

Lucky13 - Sorry to rant in your thread. I am just very upset about this battery BS on a $55K car. I do know that certain systems do start to shut down when the battery gets low. My top operation via the FOB almost never works anymore and I've even had comfort access shut down and not work. Once I had to try the remote button several times and was just about to resort to the actual key when it finally opened. And yes, the fob battery was new or at least less than 2 months old.

[CUTigers]

Originally Posted by mr_milo

Thanks for the information but personally I think this is an over-engineering design flaw. I am an EE too and I've found a few over-engineered items which turn into design flaws on this car. It's basically too smart for itself and ends up being dumb when you try to use it. Now I totally understand why Jeremy Clarkson from Top Gear went off about the I-drive. I can also tell you for a fact that the Comfort Access & Opening the top with the fob will both turn off when the battery gets low. Problem is the functions just stop working and their is nothing telling you why they stopped working. Now that's an over-engineered design flaw. It's a shame too since it is a great driving car it just becomes not a great car to drive day to day.

My question would be this: How far must I drive to "maintain" the battery??? My commute is driving 9.7 miles each way to and from work. It takes me about 21 minutes each way with a mix of city streets and freeway for a total of about 19.4 miles / 42 minutes per day. I really don't consider this a "short" drive. I mean it's not like I'm driving to the corner store and back, but it seems it is too short for the BMW. Shouldn't I have been given a disclaimer about this when I bought the car?

The statements above basically tell me I need to sell my car since I can't use it for my driving needs without buying a new battery every two years or so. I didn't buy a "plug-in" and was honestly insulted when the SA told me "buy" a trickle charger and do so. If it needs it, shouldn't they be providing one? Personally I feel the same way about "locking" my convertible when the car is in my garage with the top down...... just another bit of dumbass over engineering in my book.

Lucky13 - Sorry to rant in your thread. I am just very upset about this battery BS on a $55K car. I do know that certain systems do start to shut down when the battery gets low. My top operation via the FOB almost never works anymore and I've even had comfort access shut down and not work. Once I had to try the remote button several times and was just about to resort to the actual key when it finally opened. And yes, the fob battery was new or at least less than 2 months old.

But a generic battery from a parts store that has a 3 or 4 year warranty and get it replaced when it does after 2, if that's how long yours are lasting.

[Lucky13]

My dealer is charging $323 installed and that's the sales price "special". Going in on the 10th for that and the recall.

[NGEE]

Originally Posted by Lucky13

My dealer is charging $323 installed and that's the sales price "special". Going in on the 10th for that and the recall.

I wasn't having any symptoms, but while in the shop of other things my dealer reported that the battery needed replacement. They charged me $417 - $213 for an Exide battery and $204 for labor. Next time I'll get the tool to register it myself.

[Lux3m35i]

One of the first symptoms of a weak battery is that the comfort access don't work properly anymore. Either you need a few tries or it doesn't react at all.

Also if the engine need 1-2 seconds more to start up, your battery probably causing the problem.

And yep it is terrible what they are asking for a battery reprogramming..

[fun2drive]

I regrogrammed by battery myself using the coding software and OBDII cable I purchased. Coding software is actually a misnomer registration software is more correct and that is from bimmerfest site under the E90-2-3 section which was free.

If you wish to sell your car because you are not driving your car sufficient miles to keep the battery charged and you don't wish to use a battery tender that is your choice.
I don't mind doing that and my battery is now over 6 years old.

In the end if the driving experience doesn't outweigh the inconvience of using a battery tender once in a while you have your answer.

From what I know a failing battery will identify itself first with your clock losing time followed by other things happening all related to the nature of the electrical demands this car requires...

[mr_milo]

Originally Posted by fun2drive

For the 2011 I would let BMW do this and expect a report back that you are abusing the charging system by short use (it is actually in the manual about the battery insufficient charging with short trips). I would argue with your SA that they should replace the battery. You will get this done once but after that it is your issue.

After reading this I went back to my car's manual to re-read the thing because I never saw anything in the manual about insufficient battery charging with short trips.

I then did a PDF search of the manual to find anything related using five different search terms (battery, distance, driving, charge & short) and still came up with nothing.

Do you by chance have a page number or section for this in the manual? I think it might be relevant when I discuss this with the General Manager and/or BMW USA. Thx

[Rong335i]

I recently had comfort access issue where, 2 different key fob push buttons or capacitive door handle don't work.
However the car will still adjust seat, set radio and start the car which tells me battery on the fob is fine.
The fix was to insert key fob to car then press the start button.

Have you tried inserting your key fob to the car?

[BMW_TECH]

mr milo: regardless of driving profile, the battery should be covered by warranty; the only time it would not be is if it was run down due to misuse (ie: listening to radio with engine off for extended periods).

The amount you are driving should be enough to charge the battery sufficiently if it is a healthy battery. I'm surprised the dealer is not replacing the battery for this issue. Is this the same dealer you purchased the car from?

[GarySL]

Originally Posted by mr_milo

After reading this I went back to to re-read the thing because I never saw anything in the manual about insufficient battery charging with short trips.

I then did a PDF search of the manual to find anything related using five different search terms (battery, distance, driving, charge & short) and still came up with nothing.

Do you by chance have a page number or section for this in the manual? I think it might be relevant when I discuss this with the General Manager and/or BMW USA. Thx

It's in the warranty booklet:

Battery Care

"If your car is driven only for short distances of less than 10 miles over a prolonged period of time, without an occasional drive at highway speeds, the engines charging system will not maintain the battery. Insufficient use of the vehicle could result in short term starting problems and in the long term could damage the battery."

[MrQuickR1]

If you are a candidate for the battery cable recall, have it done. My locks wouldn't open at times with the fob and when touching the door handle it made crazy clicking sounds loud like trying to start a car with a bad battery. So far it hasn't come back after the connectors were changed out but that's only been a week. Time will tell.
for an 07, it's also time for a battery especially if it hasn't been used regularly. I look at it this way, my car is not a collectors car, so I may as well use it and not worry about adding miles to the clock