Unusual battery issue -- is this a bad IBS?

Squeak825 · 10-21-2022, 09:42 PM

2017 340xi on my second battery. I have a CTEK trickle charger that I use regularly with pigtails and a quick disconnect.

I charged it up a couple of days ago and came out this morning to the "increased discharge" warning (I used to get it before and got a new battery). But the car was fully charged just recently. Car starts fine, no issues running.

I used the Bimmerlink app to see what the IBS thinks the battery charge is, and as opposed to getting a number, I get a "-" -- as in it can't read an entry, and after driving for 10 minutes it reads at 4%. So the IBS thinks there is no charge and is slowly charging, but the battery has plenty of charge.

Pulled a cold voltage read just now, and it is sitting at 12.39V. So the battery is fine.

Does this seem like the IBS has gone wonky and is worth replacing? Is there a way to "reset" the IBS?

ImBlue · 10-22-2022, 06:52 AM

Where is the CTEK quick disconnect installed? On the battery or the hood charge terminal.

Billfitz · 10-22-2022, 08:40 AM

Quote:

Originally Posted by ImBlue

Where is the CTEK quick disconnect installed? On the battery or the hood charge terminal.

It doesn't matter. The positive charging post connects directly to the battery. I have mine permanently wired to the charging posts, with the connector extending through the lower grille so I can plug in without opening the hood.

Squeak825 · 10-22-2022, 09:05 AM

Quote:

Originally Posted by ImBlue

Where is the CTEK quick disconnect installed? On the battery or the hood charge terminal.

Under the hood with an extension routing to by the driver side windshield area for easy access.

Squeak825 · 06-19-2023, 10:16 AM

Coming back to this to close the loop.

After much debugging and taking voltage reading of cold batteries, etc., I came to the conclusion I thought the IBS was bad. It had gotten to the point where there wasn't a day where I was not getting the "Low Battery" warning on my car, but the voltage at rest was ~12.5v. Or the Bimmerlink tool would say the percentage was 85% one day, --% the next, 34% the day after, etc.

Bought the negative battery cable replacement ($99) and took 5 minutes to swap out and reset the clock. It has only been 3 days but so far so good. No more warnings, and the battery readout on Bimmerlink is exactly what you would expect it to be: consistently the same value +/- a few percentages, and no wild fluctuations.

Will continue to keep an eye on it, but looks like this solved the problem.

Wires · 06-19-2023, 01:35 PM

Stupid question, but was the battery registered when you put it in? That will also throw off the reading (going from really good to really bad like you mentioned would point to something lese though).

Squeak825 · 06-19-2023, 05:48 PM

Quote:

Originally Posted by Wires

Stupid question, but was the battery registered when you put it in? That will also throw off the reading (going from really good to really bad like you mentioned would point to something lese though).

Yes. New battery was installed by my local dealer and registered. I can see when that happened (mileage wise) inside of Bimmerlink

10-21-2022, 09:42 PM	#1
Squeak825 Enlisted Member 11 Rep 31 Posts Drives: '17 340xi Join Date: Sep 2017 Location: Columbus, Ohio iTrader: (0)	Unusual battery issue -- is this a bad IBS? 2017 340xi on my second battery. I have a CTEK trickle charger that I use regularly with pigtails and a quick disconnect. I charged it up a couple of days ago and came out this morning to the "increased discharge" warning (I used to get it before and got a new battery). But the car was fully charged just recently. Car starts fine, no issues running. I used the Bimmerlink app to see what the IBS thinks the battery charge is, and as opposed to getting a number, I get a "-" -- as in it can't read an entry, and after driving for 10 minutes it reads at 4%. So the IBS thinks there is no charge and is slowly charging, but the battery has plenty of charge. Pulled a cold voltage read just now, and it is sitting at 12.39V. So the battery is fine. Does this seem like the IBS has gone wonky and is worth replacing? Is there a way to "reset" the IBS?
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10-22-2022, 06:52 AM	#2
ImBlue Private 30 Rep 83 Posts Drives: 2016 340ix MPPSK\| 2015 R60 JCW Join Date: Jun 2019 Location: Toronto iTrader: (0) Garage List 2016 BMW 340i xDrive [0.00]	Where is the CTEK quick disconnect installed? On the battery or the hood charge terminal.
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06-19-2023, 10:16 AM	#5
Squeak825 Enlisted Member 11 Rep 31 Posts Drives: '17 340xi Join Date: Sep 2017 Location: Columbus, Ohio iTrader: (0)	Coming back to this to close the loop. After much debugging and taking voltage reading of cold batteries, etc., I came to the conclusion I thought the IBS was bad. It had gotten to the point where there wasn't a day where I was not getting the "Low Battery" warning on my car, but the voltage at rest was ~12.5v. Or the Bimmerlink tool would say the percentage was 85% one day, --% the next, 34% the day after, etc. Bought the negative battery cable replacement ($99) and took 5 minutes to swap out and reset the clock. It has only been 3 days but so far so good. No more warnings, and the battery readout on Bimmerlink is exactly what you would expect it to be: consistently the same value +/- a few percentages, and no wild fluctuations. Will continue to keep an eye on it, but looks like this solved the problem.
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06-19-2023, 01:35 PM	#6
Wires Brigadier General 1646 Rep 4,877 Posts Drives: 2016 340i xDrive Join Date: Apr 2008 Location: Calgary iTrader: (0)	Stupid question, but was the battery registered when you put it in? That will also throw off the reading (going from really good to really bad like you mentioned would point to something lese though).
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