[kerplunk38]

I have many friends with BMW's and every one of them with Efficient Dynamics is having a battery problem in these cold temperatures. I have a theory but have been able to find very little proof of why this is happening.

My theory is the Efficient Dynamics Regenerative Braking which recharges the battery while coasting is extremely INefficient in cold temperatures. If you drive a lot of highway miles at a constant speed I think the alternator does a fine job of charging your battery. If you are constantly accelerating or stopping/going in town your battery isn't charged very efficiently by the regenerative braking when it is this cold.

My wife and I work in the same building. I have a BMW and she has a brand new Lexus. Her Lexus was completely fine while my car almost did NOT start on 3 occasions in the past 3 days due to the battery being nearly dead. I have since charged it and things are back to normal. This is most likely due to the temperatures improving somewhat.

Some info on the Efficient Dynamics Regenerative Braking.

[Lost Horizon]

Originally Posted by kerplunk38

I have many friends with BMW's and every one of them with Efficient Dynamics is having a battery problem in these cold temperatures. I have a theory but have been able to find very little proof of why this is happening.

My theory is the Efficient Dynamics Regenerative Braking which recharges the battery while coasting is extremely INefficient in cold temperatures. If you drive a lot of highway miles at a constant speed I think the alternator does a fine job of charging your battery. If you are constantly accelerating or stopping/going in town your battery isn't charged very efficiently by the regenerative braking when it is this cold.

My wife and I work in the same building. I have a BMW and she has a brand new Lexus. Her Lexus was completely fine while my car almost did NOT start on 3 occasions in the past 3 days due to the battery being nearly dead. I have since charged it and things are back to normal. This is most likely due to the temperatures improving somewhat.

Some info on the Efficient Dynamics Regenerative Braking.

That might be the smoking gun... the alternator is not in the circuit if you are on the gas.. and then you are sucking down the amp-hours at a great rate with ASS.. plus your battery is only 50% effective @ -20, and 30% @ -40.. then you are loading it up with the heating stuff.. big amps on the rear window, the fan, heated seats, wheel, lights.. plus you are idling in stop and accelerate traffic...

So you are driving to work downhill electrically, and never recover fully, net loss of amp-hours each day .. unless your commute is @ 60mph for one hour, coasting at cruise to keep the alternator running .....

[sirdrebin]

Originally Posted by skypx

Here's my thing, as expensive as these batteries are I not taking any chances! Dealerships seem to look for any excuse to deny a warrantee claim.

After driving our X5 for 1hr 30 minutes I connected the Ctek 4.3 battery charger and selected the snowflake/AGM mode. 7 hours later the battery was fully charged, so obviously driving for 1hr 30 minutes did not charge the battery completely. I can't imagine getting the "High Battery Discharge" warning and only driving it for 10 minutes.

I have my 2013 335xi parked in an apartment building garage where the spaces have absolutely no accessability to any utilities, incl. NO electric outlets. Thus the usual type of charger, which has to be plugged into an outlet during its charging of the car battery, just won't do. Does anyone know of any charger which, itself, can first be charged at an outlet somewhere else and then brought/hooked up to the car battery to do its job??

If so, could you post the brand, website(s) or other details. Thanks.

[BavarianFanatic]

I would have to imagine that the coding for management of charging is intelligent enough to not freewheel the alternator during high demand periods. Not that I use it often, but my experience has been that ASS doesn't ever engage when it's extremely cold. It just keeps running at every stop.

[kerplunk38]

I think Lost Horizon stated it very well.

My ASS is disabled by default so that isn't a factor for me in any condition.

[canbmw]

For what it's worth I had the same low battery message for a couple of days here in Edmonton once it got colder and my garage heater died. Interestingly, my (new) charger indicated <25% charge remaining when I hooked it up. I wonder if it would have died had I kept on with my same driving habits and no charge.

I do find it alarming that so many people are having the same problem. I mean how many new cars out there in Canada these days have a problem with dead or nearly dead batteries??

[blegare]

I had the same message twice last week (-30 to -35 here). Efficient Dynamics is a great thing, but it *must* be intelligent enough use the alternator to fully charge the battery on cold weather days.

The fact that a brand new 60K$ car can't start on cold weather days because of some sort of bad energy management is beyond belief.

BMW need to fix this ASAP!

[Bassthe1st]

It would be important that everybody having problems complain to their dealership and maybe call BMW directly. This is not normal and they MUST come up with a fix that is not a battery charger...

[Lost Horizon]

Originally Posted by canbmw

For what it's worth I had the same low battery message for a couple of days here in Edmonton once it got colder and my garage heater died. Interestingly, my (new) charger indicated <25% charge remaining when I hooked it up. I wonder if it would have died had I kept on with my same driving habits and no charge.

I do find it alarming that so many people are having the same problem. I mean how many new cars out there in Canada these days have a problem with dead or nearly dead batteries??

The smart charger 25% mark is bogus.. mine does the same thing. It's going on static voltage, but looks like it bases that on 70F . At -40, the battery will indicate low voltage, even tho it has a full charge, becase only 30% is available at that temp..

It starts out showing 25%, but at 3.5A charge the battery shows topped up in an hour or 2.. that is only adding a max of 7 Ah, and the battery capacity is over 100 Ah, meaning it was really only down less than 7%..

Unless you are paying many hundreds of dollars for your certified AGM charger, take what it says with a grain of salt...

[gomichaelkgo]

I got this message over the summer when my driver door proximity lock sensor was malfunctioning. I think the sensor kept waking up a module and draining the battery.

[BavarianFanatic]

Originally Posted by gomichaelkgo

I got this message over the summer when my driver door proximity lock sensor was malfunctioning. I think the sensor kept waking up a module and draining the battery.

This could very likely be the culprit for some of the folks who are experiencing issues. The cold weather could simply be exacerbating it.

I used to have an '04 E83 X3 that had terrible parasitic drain issues (a great number of early X3s had this problem). It could range from a low battery after 2 days sitting to a completely flat battery over a single night. After many years of just dealing with it, I finally found the issue to be corrosion on one of the connectors on the telematics control unit in the rear quarter panel. There was a perforation worn into one of the sunroof drain lines that was dripping on the TCU. Over time there was a build-up of minerals on the terminals that was causing a short. I cleaned it up, fixed the drain line and never had another problem. There have been many times over the years that BMW has had issues with body modules causing excessive drain that's difficult to detect/trace.

It might be worthwhile for those having this issue to keep tabs of their battery voltage once the weather "normalizes". For those who are operating in the "danger zone" by storing the car for extended periods or just taking very short trips, I think the experiences indicated would be expected given the circumstances.

[gomichaelkgo]

Originally Posted by BavarianFanatic

This could very likely be the culprit for some of the folks who are experiencing issues. The cold weather could simply be exacerbating it.

I used to have an '04 E83 X3 that had terrible parasitic drain issues (a great number of early X3s had this problem). It could range from a low battery after 2 days sitting to a completely flat battery over a single night. After many years of just dealing with it, I finally found the issue to be corrosion on one of the connectors on the telematics control unit in the rear quarter panel. There was a perforation worn into one of the sunroof drain lines that was dripping on the TCU. Over time there was a build-up of minerals on the terminals that was causing a short. I cleaned it up, fixed the drain line and never had another problem. There have been many times over the years that BMW has had issues with body modules causing excessive drain that's difficult to detect/trace.

It might be worthwhile for those having this issue to keep tabs of their battery voltage once the weather "normalizes". For those who are operating in the "danger zone" by storing the car for extended periods or just taking very short trips, I think the experiences indicated would be expected given the circumstances.

The E60 5 series had pretty bad problems with this. An expensive module was located IN THE SPARE TIRE WELL and was prone to corrosion.

[Elk]

Originally Posted by blegare

The fact that a brand new 60K$ car can't start on cold weather days because of some sort of bad energy management is beyond belief.

BMW need to fix this ASAP!

I would not hold your breath.

This has been an issue on iDrive cars for over a decade when BMW introduced the system on the 7-Series. It is not iDrive per se, but the tremendous amount of parasitic loss which accompanies the system.

It first arose with owner who parked their 7 at their second home and it would not start in warm weather after sitting for six weeks or so.

As I and others have suggested, buy a charger and use it when it is extremely cold and/or you are not going to drive the car for a while. It is a trivial fix and takes less time than posting a complaint on a forum.

[Lost Horizon]

Originally Posted by Bassthe1st

It would be important that everybody having problems complain to their dealership and maybe call BMW directly. This is not normal and they MUST come up with a fix that is not a battery charger...

Welllll.... I've been driving cars (and airplanes) in cold weather for a very long time, and battery technology still sucks when starting in cold weather. It's the physics, Doctor. The only warning you got then was that all the starter motor would do was groan then click if you didn't plug it in.. and plug it in meant a block heater (or two) plus an oil pan heater, plus a battery blanket.. The battery and thermal physics haven't changed much, but the demands on a battery have gone up quite a bit.. how many here who are outraged have those items on their car now? I'll bet not many.

At least BMW is conservative and maybe warns you too soon, but most here COULD start their car with the warning. In the old days of groan and click, you walked, and you'd better have a parka with a hood..

[Bassthe1st]

Well, I brought the the car in to check something(lights leveling problem) and talked again to the tech guy and a mecanic. I was told the same thing again: The discharge is normal, I don't drive enough(30km per day, WTF???) and the heater will never be working on very cold temperature unless the battery is plugged on a charger. So all design flaws of the car and serious ones at that. Of course, BMW and the dealer will throw the ball at each other and won't do anything. I'm considering my options, but I think there are few...

[mags]

this happened to a friend of mine with a fully loaded 550xi F10, several trips to the dealership (the frst 3 or 4 they looked at him as if he had 7 green antennaes on his head).
At his 4th or 5th visit they replaced the battery with a bigger one. Since then I do not think he has had any issues.
Could be an AGM and low low temp issue.

[kerplunk38]

This is not purely about physics as someone inferred. It also isn't just about getting a warning on iDrive. There is a problem with the way the battery is managed on these vehicles that does not match many of our driving habits. Things such as the heat/defroster which contribute to driving comfort and in some cases safety were being disabled. This is not acceptable in any car let alone an expensive performance sedan.

I eliminated the problem today. It was a fairly simple solution for me. I traded the car for a more reliable brand.

I don't hate BMW. I am not even angry with them. I read about this issue before I purchased the car and I am angry at myself for not believing the numerous complaints on this very issue.

I loved the 335i and the way it felt when everything worked properly. But for me I need a reliable car which doesn't make me nervous every time the temperature dips. I need a car which doesn't make me think twice when my family is in the car on these cold, harsh days.

I will summarize by saying I think we each have our own definition of the Ultimate Driving Machine. One of my criteria for such a machine is reliability and/or confidence that issues like this will be resolved by the mother company in a reasonable amount of time. I very much appreciate the engineering, performance, and beauty of BMW's. Hopefully, I do not start a flame war here .

[HighlandPete]

Originally Posted by Elk

...As I and others have suggested, buy a charger and use it when it is extremely cold and/or you are not going to drive the car for a while. It is a trivial fix and takes less time than posting a complaint on a forum.

^^^^

Such simple advice. These days we want all the electrical consumers, plus fuel efficiencies and are shocked when we have to top up a battery in some conditions.

Our alternators are around 200 amp capacity these days, but our consumer energy load still has to be managed, as energy demand is really too high even for a 200 amp alternator to cope with in some conditions.

I go back to the time we had a dynamo and very limited electrical demands, we still had to trickle charge our batteries in winter time, if we didn't drive enough miles from a cold start, as the battery slowly depleted. And not in the coldest climates either.

As manufacturers move to more advanced energy management, I'm sure more users will find the limitations.

HighlandPete

[tdizzle]

I got the warning the other day randomly (same driving to and work habbit as normal) and the weather wasn't even that cold as I think it didnt even dip below 40 degrees overnight.

Last week it was below freezing for 2-3 days straight and I had no issue, even when I didn't drive it for a 36 hour period.

Maybe it was windy inside my garage that night and my car thought I was trying to get in, even though my key was out of range...

[Elk]

Originally Posted by HighlandPete

As manufacturers move to more advanced energy management, I'm sure more users will find the limitations.

I am certain you are correct. More users will experience these issues as they replace their older cars with those containing the latest technology as well.

Consumer desire and regulations require the most efficient cars possible.

Consumers simultaneously demand a tremendous number of electronic gadgets with near instantaneous start-up/boot times.

These competing demands necessarily come into conflict. Achieving the perfect balance under all possible conditions is near impossible.

BMW is presently pushing the balance toward efficiency and gizmo support. Perhaps it has gone to far. If people stop buying the cars as a result, BMW will modify its approach.

Many here will complain bitterly however if the efficiency decreases and the electronic readiness is backed off.

[martinf79]

Well ... Happened again.. Toronto got hit w -30 C weather 2 days back to back and I got the warning again. Charging my battery as we speak. This can't be the way these cars are designed??? I mean I get what everyone is saying... But my god... Can I only drive 2 days back to back when it gets cold out??? I have a service appointment scheduled for Monday... Will see what the battery diagnostic says.

[tdizzle]

Happened again to me over the weekend. Wasn't even freezing temps. Then I drive it on a short trip that wasn't even enough to get the car to normal temp and let it sit for two days and no warning. I've got no clue why it does it. Can't be the cold as when it's really cold I've never seen the warning...