[Dabozo]

Did some searching, found some explanations but what I don't understand is why my battery tender was not enough to solve my problem.

I don't DD my car and I don't drive in winter however, since I miss the car so much, I've taken her for a spin here and there when weather permits-albeit short drives. Because I decided I would do this this winter, I made the mistake of not connecting a battery tender thinking I didn't need to. As a result battery died on me the other day.
So I connected my battery tender and left it for a full day. Next day it read that the battery was 100%.
However, I go to start it and I get these two messages one after the other!
I don't get it....do I just have a s**t charger, a heavy paperweight (battery)or is just a good long drive in order?

[Zippster]

Don't know, but the battery is quite large 900CCA, so it should take awhile to go down, but it should be under warranty so I would bring it in and see what is going on.

However, if you can start it, check the running voltage and see if its 14 volts or so. Now it will depend on how far down the battery is, but it should come up to near that voltage I think. I will say that the charging system on these cars is very different than any other car I have owned. If you get a new battery is needs to be programed into the car as a new battery or it will not get charged properly.

Let us know what you find out its important information especially for those who don't drive in the winter.

[Dabozo]

Will do. I had my last car for about 5 yrs. same routine. No winter driving except for the odd opportunity during winter...no tender...no problem! The problems I'm experiencing now with only 2000+ km are the same problems I only encountered in my 4th year with the previous car. Granted I'm sure there is more 'phantom ' electrical draw with the m2 vs my 2009 but geez...:

[Zippster]

Originally Posted by Dabozo

Will do. I had my last car for about 5 yrs. same routine. No winter driving except for the odd opportunity during winter...no tender...no problem! The problems I'm experiencing now with only 2000+ km are the same problems I only encountered in my 4th year with the previous car. Granted I'm sure there is more 'phantom ' electrical draw with the m2 vs my 2009 but geez...:

Yes, I have noticed noise and such when I open the door and to take care to kill the electrics by either arming upon exit or pushing the start button one more time before exiting the car. But still 900 CCAs is the biggest damn battery I have seen in a car, but it's also the first that I have owned that stops and starts itself at idle - if you let it. So for that reason, I suspect it needs to have some serious grunt.

Batteries that sit for long periods can sulfate which can/will damage them, so it's important to not let that happen. Add in all the parasitic draw and sitting for a month or more and it might be bad for these batteries, but I am interested in what you find out, again thanks for posting this.....

[chmura]

Take it to the dealer. My 2011 M3 sat for a month or even two months at a time with no problems. I never used a battery tender.

[Destroya]

[QUOTE=Dabozo;21293647]

As a result battery died on me the other day.

How long did you let it sit between drives? If I can't get a drive in on a weekly basis I back the car out of the garage and let it run for half an hour. Hopefully I am keeping the battery charged this way.

[Dabozo]

[QUOTE=Destroya;21294903]

Originally Posted by Dabozo

As a result battery died on me the other day.

How long did you let it sit between drives? If I can't get a drive in on a weekly basis I back the car out of the garage and let it run for half an hour. Hopefully I am keeping the battery charged this way.

On average this winter...car would be driven (short distances) or at the very least idled every 10-15 days.

I did some voltage testing - keep in mind I had the tender hooked up prior. Therefore the resting voltage was 13.39v and the running voltage was 14.88v.
Shut down after a bit and got the same warning and car shut down all accessory power.
Came back 2 hours later and resting voltage was 12.71.
Went for a nice drive, returned, shut ignition off and no warning this time. Checked voltage and it was 13.78v. So perhaps a long..ish drive was all that was necessary.

I've left the battery tender unplugged tonight. Will check voltage in am to see if battery kept most of its charge.

[Tag]

You can view the system voltage via the hidden menu. Look on YouTube for videos on how to get into the hidden menu.

With the engine off and no lights on go to the system voltage display in the hidden menu. The voltage should be around 12.4~12.6v, if it's slightly below the battery is not fully charged. Once you start the car it should display 14.5~15v.

Not all battery chargers are great, a lot of them are terrible and can indicate the battery is fully charged when it is not. Some chargers also go bad so I would not rely entirely on that. To really figure out what's going on you'll need a multimeter that has the min/max function and understand how to use it. Otherwise just take it to the dealer.

[Dabozo]

My meter does not have that function.

I'll check it in the morning. If I get the warnings again I'll bring it in. Hopefully they don't give me a hard time.

[Tralfaz]

I had a 135i before my M2. I took a 3 week vacation once while I had it. When I came back and started my car the settings had been reset. The car still started and was OK, but I guess it went into some low power mode. It was a bit odd.

[Zippster]

[QUOTE=Dabozo;21295816]

Originally Posted by Destroya

On average this winter...car would be driven (short distances) or at the very least idled every 10-15 days.

I did some voltage testing - keep in mind I had the tender hooked up prior. Therefore the resting voltage was 13.39v and the running voltage was 14.88v.
Shut down after a bit and got the same warning and car shut down all accessory power.
Came back 2 hours later and resting voltage was 12.71.
Went for a nice drive, returned, shut ignition off and no warning this time. Checked voltage and it was 13.78v. So perhaps a long..ish drive was all that was necessary.

I've left the battery tender unplugged tonight. Will check voltage in am to see if battery kept most of its charge.

I think at this point you need to have the battery load tested, it just might have a bad cell. I have had them go bad this way, the last one was a AGM motorcycle battery. AGM is what is in the BMW M2, it sounds like a classic bad battery i.e. wont hold a charge.

[Zippster]

[QUOTE=Dabozo;21295816]

Originally Posted by Destroya

On average this winter...car would be driven (short distances) or at the very least idled every 10-15 days.

I did some voltage testing - keep in mind I had the tender hooked up prior. Therefore the resting voltage was 13.39v and the running voltage was 14.88v.
Shut down after a bit and got the same warning and car shut down all accessory power.
Came back 2 hours later and resting voltage was 12.71.
Went for a nice drive, returned, shut ignition off and no warning this time. Checked voltage and it was 13.78v. So perhaps a long..ish drive was all that was necessary.

I've left the battery tender unplugged tonight. Will check voltage in am to see if battery kept most of its charge.

Let me explain that a little more, I have had a battery read the same voltage 12.7 and not start the vehicle, it was bad. You can easily test for this by letting the car sit for a day or so then do your test again and see if you get the warning again. If not, you might be ok.

[Dabozo]

[QUOTE=Zippster;21297736]

Originally Posted by Dabozo

Let me explain that a little more, I have had a battery read the same voltage 12.7 and not start the vehicle, it was bad. You can easily test for this by letting the car sit for a day or so then do your test again and see if you get the warning again. If not, you might be ok.

I think you will be proven correct. Will test in a few hours (24 hrs after sitting with no battery tender connected).

[P4rD0nM3]

My M2's been in my garage this whole winter. I usually start it once every two weeks before I clean the dust off and that usually last for like 15-30 seconds depending on how much I want to hear the cold start. Never really used a battery tender. This Saturday I drove to Chicago Auto Show because hell it was like 65+ and it was just fine.

[Dabozo]

[QUOTE=Dabozo;21297871]

Originally Posted by Zippster

I think you will be proven correct. Will test in a few hours (24 hrs after sitting with no battery tender connected).

Battery voltage was 12.74v this afternoon....roughly 24 hrs later..Started with no problem and so far no Battery warning.
I'll keep my eye on it but perhaps I dodged one and all is back to normal.

Anecdotally, my neighbour who has owned bmw's for a long time saw me messing with my battery and he told me he has had issues with his batteries with every car!

[Zippster]

[QUOTE=Dabozo;21299888]

Originally Posted by Dabozo

Battery voltage was 12.74v this afternoon....roughly 24 hrs later..Started with no problem and so far no Battery warning.
I'll keep my eye on it but perhaps I dodged one and all is back to normal.

Anecdotally, my neighbour who has owned bmw's for a long time saw me messing with my battery and he told me he has had issues with his batteries with every car!

Well good news then. Thanks for keeping us up to date.

Maybe something was left on that drained it. At any rate if anything happens I hope you get it covered under warranty. I bet replacing a 900CCA battery at a dealer will cost plenty.

[doug_999]

Originally Posted by P4rD0nM3

My M2's been in my garage this whole winter. I usually start it once every two weeks before I clean the dust off and that usually last for like 15-30 seconds depending on how much I want to hear the cold start. Never really used a battery tender. This Saturday I drove to Chicago Auto Show because hell it was like 65+ and it was just fine.

That's really not good for the car or the battery. A tender will increase the life of the battery and if you do start the car, bring it up to temp before shutting it off.

Ctek makes some nice chargers and they are not expensive.

[P4rD0nM3]

Originally Posted by doug_999

That's really not good for the car or the battery. A tender will increase the life of the battery and if you do start the car, bring it up to temp before shutting it off.

Ctek makes some nice chargers and they are not expensive.

Was gonna get this.

http://www.shopbmwusa.com/PRODUCT/46...TTERY-CHARGER/

[DivideBYZero]

Originally Posted by P4rD0nM3

Was gonna get this.

http://www.shopbmwusa.com/PRODUCT/46...TTERY-CHARGER/

That's a rebadged CTEK, so you can get that, or save some $$ by getting the original CTEK Version. I have it and it's a very good unit.

[doug_999]

Originally Posted by P4rD0nM3

Was gonna get this.

http://www.shopbmwusa.com/PRODUCT/46...TTERY-CHARGER/

As DivideBYZero points out, you can save some cash and buy one of these:

https://www.amazon.com/CTEK-56-864-Automatic-Battery-Charger/dp/B006G14FK8

Use the snowflake mode and connect under hood. Pm me with any questions.

[///M²]

I've had my car parked for 3 months now, drove it twice in that period and had no issues. Car is not hooked up to a battery tender and all is fine.

[doug_999]

Originally Posted by M2ME2

I've had my car parked for 3 months now, drove it twice in that period and had no issues. Car is not hooked up to a battery tender and all is fine.

All is not fine. You will find that your battery needs replacing much sooner because of this.