[gsocket]

I’m getting desperate and really hoping someone here can help me with my battery drain saga. Thanks for reading and any help you can provide. Here’s what’s going on.

Intro: I have a 2014 328i with x drive. 65k miles and have been taking pretty good care of it. It was due for a new battery last year and I got an AGM battery from AdvanceAuto. Same specs as the OEM one and less than half the price. I registered it with Rheingold and all was well.

Part 1: I started driving much less than I used to when COVID started and the finally battery died. Jumped easy. The same thing happened about a month later and jumped again. So, I assumed the battery kept dying since I wasn’t driving enough. I now drive almost every day for about 15 min. More on the weekends. The recently battery died again though and this time, was really hard to jump. So, I took it back to AdvanceAuto to test it. They said it was low on charge but the battery tested fine. I got it charged up and thought I just needed to drive more often.

Part 2: I was about to trade cars with my wife who drives much more than I do but then it died again. This was a few days after I drove it hard all weekend. So, I decided to take the plunge and see if the dealership could diagnosis it for me. $225 later, they said my batter was bad. AdvanceAuto tested it a few weeks ago but I assumed BMW must know more about my car. Instead of paying the dealership $500 for a new battery and coding, my good friends at AdvanceAuto gave me a new battery for free. As an aside, these guys are really nice – I didn’t have a receipt, the battery was a year old and it passed their test again. So, free new battery, showed 99% charge, registered with Bimmerlink (WAY easier than Rheingold) and I thought I was good to go.

Part 3: After showing 99% charge yesterday, I started it up and it was down to 79%. Hoping someone can tell me this is normal but it seems very wrong to me.

So far, I think the fuel pump works (it makes the noise it’s supposed to at least). I tested all the fuses and they’re fine. I think/hope the alternator is ok since the battery will increase a few percentage points after I start driving. There are a few codes but I haven’t been able to find much on them. Would also hope that if any of them were the issue, the dealer would have picked up on that.

8042CF: Front interior light button: button stuck or short circuit to ground
E58468: BODY-CAN Control Module Bus OFF
B7F8C3: CID does not respond (hardware error: failure of CID communication)
80444A: Inside mirror, electochromic: internal error
480AB8: Internal condition management Complete scope of monitoring
1F0905: DME, internal error, Valvetronic: current implausible
CD9437: FlexRay, message (request wheel torque drive train total stabilization / target distribution longitudinal torque front axle rear axle, 43.1.4) in the event of undervoltage: communication error

Any thoughts would be very much appreciated!

[chowser51]

Dash cam hard wired?

Keyfob kept far away from car when not being driven?

[gsocket]

thanks for the quick response - no dash cam and yes, i keep the key fobs away from the car

[im_an_alien]

You mentioned the battery was due for a change...was it doing any of this before you changed the battery the first time? If not, why did you change it? Age? Whatever the case, looks like the car is not charging the new battery. I don't believe in coincidences....

[gsocket]

It was just due for a change (6 years old and 60k miles). Car was fine before and for about 6 months after I put the new one in. Curious why you think it's not charging though. The percent charge goes up after I drive it. It just seems to be draining when it's off

[Icarium81]

Same issue, battery would be nearly stone dead after an hour long wash and wax with just music playing.
Then again with no music, only opening the trunk a half dozen times (cleaning supplies) so lights would pop on for that time.
Back to bmw 3 different times and they all claimed that it's completely normal and that it happens to their cars all the time (the people at the dealership who own bmws). What a load of shit. Clearly something is wrong somewhere, our battery couldn't have been 3 years old (2018 bmw). In my 23 years of driving, across 15 or so personal vehicles, I think I've changed ONE battery... MAYBE. And none of those cars were new. A few were less than 5 years old and a few less than 10, but most were 10 to 20.

[oranga]

I had a similar situation this summer where my battery died, got it replaced under warranty, then it died again 2 days later. My mechanic and I think the likeliest cause was a little "smart car" transmitter i plugged into my OBDII that could read basic car parameters (kind of like bimmerlink but more generic)

Makes sense except that it was plugged in for several months before with no issues, but anything is possible

So i know it's basic, but make sure you don't have anything plugged into your OBD, or cigarette lighter outlets, or anything like that.

[im_an_alien]

OP states car was fine before the battery change, no problems with anything plugged in etc. So why the sudden gremlins soon after the battery change? Cig lighter ports turn off after a few minutes. I'm thinking it's battery related, it's the common denominator. Either that or it wasn't registered properly...
OR, in a twist of coincidence, the car developed parasitic drain shortly after the battery was changed...
OP, does the car go to sleep completely? You can check if the car is asleep by verifying that the headlight switch and hazard switch backlight is off...

[Billfitz]

Park it for the night and make sure it's fully charged, around 13v. The next morning see if it's at least 12v. If so you're probably OK. If not repeat the process, but this time disconnect the battery negative terminal. If it still loses its charge overnight the battery is bad. If not you've got a parasitic drain when the car is not running.

[Zanity]

What a strange gremlin, maybe it wasn't reset properly? I'm still on my OEM batt from nov 2013 and I drove once a week for this whole year now too due to covid, but I have the OBD veepeak, the dashcam and the dinan boost controller all plugged in the entire time draining and I'm still hovering between 60%-80% charged according to my bimmerlink readout. Honestly you should have left it, if it ain't broken, don't touch it. The OEM battery was top quality.

[dmaxdmax]

...and you can use your cluster display to monitor voltage while the car is on. Might be your alt (though that 'should' throw a code), or a corroded loose connection?

I believe the car will let the battery charge drop down a bit before charging it up again...so I've heard...but don't trust me on that. I'm remembering something like 80% is the most efficient state for it to be in.

Good luck!

[Billfitz]

When new the battery capacity is more than it needs to be. This allows not fully charging it, which increases battery life. As the battery ages its ability to hold a charge goes down, so to compensate for that the charge level is increased over time. This is why a new battery must be registered. If not registered the car doesn't know it's new and will charge it as if it was old, reducing the life of the battery.

[bbbbbb2020]

Originally Posted by gsocket

I’m getting desperate and really hoping someone here can help me with my battery drain saga. Thanks for reading and any help you can provide. Here’s what’s going on.


Any thoughts would be very much appreciated!

What you are experiencing is a parasitic current drain of some kind. This happened to me once as well, but not on F30.

The solution is simple, but you need to find a proper electrician (expert).

You fill the battery of the car, by driving. Then go to the expert ASAP. Turn the car off and wait for the car to turn off everything. This may be 20 minutes or so.

Then the electrician measures the current drain at the battery. It should be more than 0. Then electrician pulls circuit breakers out, one at a time. Then it still measures the current drain.
At some point, the current drain falls to 0. Then all electrical devices bound to that circuit breaker must be searched and disconnected. Your list of errors may help. At some point the current drain falls to 0, even after circuit breaker inserted but the device is disconnected.
That device or a car part needs to be replaced or serviced.
In my case, some in device relay was stuck in the position and was pulling parasitic current. In that case only a relay was replaced.

You certainly need an expert in electric car wiring.

But if electrician measures there is no parasitic current drain, then there must be a fault with a car battery registration or battery wiring loose or something, i.e. the battery is not recharging correctly. It is very very rare, new battery would be faulty.

[gsocket]

Really appreciate all the responses. Battery showed 82% this morning and was 13-14v. My hope is that I just damaged the old battery by not driving enough. Will continue to monitor and keep my fingers crossed. Really good piece of advice about an electrical expert though. My sense is that dealerships (in general) rely too much on interpreting codes based on what is prescribed by the manufacturer. Kind of regret going there in the first place but it’s hard to find a trusted, skilled mechanic these days.

[bbbbbb2020]

Originally Posted by gsocket

Really appreciate all the responses. Battery showed 82% this morning and was 13-14v. My hope is that I just damaged the old battery by not driving enough. Will continue to monitor and keep my fingers crossed. Really good piece of advice about an electrical expert though. My sense is that dealerships (in general) rely too much on interpreting codes based on what is prescribed by the manufacturer. Kind of regret going there in the first place but it’s hard to find a trusted, skilled mechanic these days.

My F30 was driven once a month for a certain period of time and even now it's sitting in a garage for about 45 days. No problems with starting or driving the car, no matter I have a dash cam connected and it's turned off after 20 minutes, so it's draining a battery for 20 minutes.

It's 2016 F30 and still having the original battery.

[Billfitz]

Originally Posted by gsocket

Battery showed 82% this morning and was 13-14v.

82% doesn't matter, 13-14v does. That doesn't mean you don't have an intermittent power drain somewhere that might kill it again, but it does indicate that the battery is fine.

[Pray for Mojo]

When you updated the car for the new battery did you adjust any spec difference like CCA and reserve capacity? You didn't put an OEM Exide AGM in, so there is probably a difference in those specs.

[gsocket]

Originally Posted by Pray for Mojo

When you updated the car for the new battery did you adjust any spec difference like CCA and reserve capacity? You didn't put an OEM Exide AGM in, so there is probably a difference in those specs.

I did not but I think the specs were almost identical. Forgot what my original was but the new one is:

Amp Hour: 95.0 AH
Cold Cranking Amperage: 900 A
Cranking Amperage: 1000 A
Reserve Capacity: 160 min
Voltage: 12.0 VDC

Here's the link

[HighlandPete]

Normally you get a warning if the battery drain is outside the normal working parameters while sleeping. Something like "Increased battery discharge when stationary" and a check message logged as well.

[tardboi]

Originally Posted by gsocket

I did not but I think the specs were almost identical. Forgot what my original was but the new one is:

Amp Hour: 95.0 AH
Cold Cranking Amperage: 900 A
Cranking Amperage: 1000 A
Reserve Capacity: 160 min
Voltage: 12.0 VDC

Here's the link

I think its recommended to go with 92AH if you don't want to re-code, but I have no idea if 95AH could confuse the computer this badly. (assuming your original was a 90AH)

[Zanity]

Originally Posted by bbbbbb2020

What you are experiencing is a parasitic current drain of some kind. This happened to me once as well, but not on F30.

The solution is simple, but you need to find a proper electrician (expert).

You fill the battery of the car, by driving....

It's easier to just buy a battery tender to fully charge that way IMO.

[HarryTee]

Originally Posted by Zanity

It's easier to just buy a battery tender to fully charge that way IMO.

What an ingenious way of solving problems!