[bmw335ie90]

So i bought a new to me e90 and am having issues with a high battery discharge notification. I have searched around and have narrowed it down to a couple possibilities. Here is what i have done so far:

1. Disconnect battery and attach multimeter in series to measure the power draw. It starts out around 8-11A and when the car goes to sleep after about 20 mins the draw is 10 mA. Every once in a while i can hear the fuel pump cycle, this is without opening a door or waking the car. When the pump cycles the power draw goes up to about 1-2A for the few second it cycles. Is this normal?

2. Let car sit for 5 days. Day 1 the battery voltage was 12.25V. By day 5 the battery measured 12.16V. When i started the car i was greeted by the battery discharge high message again. When the car sits for less than 2 days i never get the high discharge message.

3. Next steps, remove battery and have it tested. Battery is from 10/14 so this could possible be bad. Battery is OEM Excide. I noticed that the battery drops a full 1.0V when waking the car. For instance, the battery measures 12.5V when car is asleep. I open the door and it drops to 11.5V and slowly increases back to 12.5V over the next 5-10 mins. This does not seem normal and could indicate a bad battery?

4. IBS, there seems to be no good way to rule out the IBS. I have thought about removing the IBS and carrying out the same test as step 2. If the battery voltage holds better maybe the IBS is to blame?

[opjose]

How old is the battery?

What is the voltage after a full charge?

[BMW ONLY]

Originally Posted by bmv335ie90

So i bought a new to me e90 and am having issues with a high battery discharge notification. I have searched around and have narrowed it down to a couple possibilities. Here is what i have done so far:

1. Disconnect battery and attach multimeter in series to measure the power draw. It starts out around 8-11A and when the car goes to sleep after about 20 mins the draw is 10 mA. Every once in a while i can hear the fuel pump cycle, this is without opening a door or waking the car. When the pump cycles the power draw goes up to about 1-2A for the few second it cycles. Is this normal?

2. Let car sit for 5 days. Day 1 the battery voltage was 12.25V. By day 5 the battery measured 12.16V. When i started the car i was greeted by the battery discharge high message again. When the car sits for less than 2 days i never get the high discharge message.

3. Next steps, remove battery and have it tested. Battery is from 10/14 so this could possible be bad. Battery is OEM Excide. I noticed that the battery drops a full 1.0V when waking the car. For instance, the battery measures 12.5V when car is asleep. I open the door and it drops to 11.5V and slowly increases back to 12.5V over the next 5-10 mins. This does not seem normal and could indicate a bad battery?

4. IBS, there seems to be no good way to rule out the IBS. I have thought about removing the IBS and carrying out the same test as step 2. If the battery voltage holds better maybe the IBS is to blame?

Just get a new battery and program it or remove the current battery and charge it slowly and reinstall. One tip to stop the draw when locking the door: lock the car and then unlock it. In 2 minutes the car locks itself but will not drain the battery as much as when you lock and walk away. You could also wire a solar trickle charger and let it be charged when there is sufficient light.

[bmw335ie90]

Originally Posted by opjose

How old is the battery?

What is the voltage after a full charge?

I have not seen that battery voltage higher than 12.3V, usually around 12.2V after driving it around for a while. Battery is from 10/14

[tcphoto]

I received the "High Battery Discharge" notice, took it tested at 12v and everything was fine for a few weeks then nothing. I would check for a date on the battery and will wager that it's about five years old. I bought an Autozone replacement and Carly App to reprogram it and all is well. Take care of it now or run the chance of being stranded.

[ewicky]

Originally Posted by bmv335ie90

I have not seen that battery voltage higher than 12.3V, usually around 12.2V after driving it around for a while. Battery is from 10/14

This is very bad. A basic google search would reveal a full charged 12V lead is measures 12.6 open terminal.
Either the battery isn't being charged when the car is running or, more likely, the battery probably has a shorted cell.

[bmw335ie90]

Originally Posted by ewicky

This is very bad. A basic google search would reveal a full charged 12V lead is measures 12.6 open terminal.
Either the battery isn't being charged when the car is running or, more likely, the battery probably has a shorted cell.

Okay thanks, I have replaced several batteries over the years and never have measure a voltage that high, usually 12.4 is typical for my new batteries. I am still leaning towards a failed battery based on the voltage drop when load is applied

[cdm244@gmail.com]

A few thoughts:

I agree that the generally low voltage does point to a battery - or possibly a bad ground (though a 2011 seems a bit new to develop the ground strap problem).

The real curiosity is the fuel pump cycling - this acts as if the ignition is staying in the "on" position (with the pump trying to periodically pressurize the fuel rail), maybe from an ignition relay stuck in the closed position. Of course then we have the anomaly of how the system can drop into sleep mode with the ignition still active. Your current draw numbers are correct for both active and sleep mode - except of course for the spike when the pump runs.

By the way how are you checking the current with your DVM? If at the battery just having the trunk open will keep the bus active. I have a earlier post suggesting how to check using the under hood jump points - on LCI E90s the hood is not switched electrically so it can be left open.

[mecheng77]

When the battery is connected you will not read
12.6v, only if disconnected.

I read 12.2v on my fully charged battery connected. It is new.

[Cruiser124]

I had battery discharge on a 335 I picked up recently. I disconnected the terminals, left the battery in the car, and trickle charged on 2amp overnight. No problems since.

Here's what my schwaben scan tool was showing. Day 3-5 was pre charge. I'd charge it, if it doesn't hold replace it.

[ewicky]

Originally Posted by bmv335ie90

I have not seen that battery voltage higher than 12.3V, usually around 12.2V after driving it around for a while. Battery is from 10/14

I reread the thread and there is conflicting information. In part 3, you first state that you see 12.5V, which is good. Then later say you've never seen above 12.3. In any case, I would hazard a guess that the car waking up repeatedly and that's what's draining the battery. The IBS (I think) stores the reason for the most recent wake-up. I can't remember how to pull that info; do some more searching I guess.
After fixing the wake-up issue, you'll probably have to replace the battery because it's too worn an this point.

Originally Posted by ewicky

This is very bad. A basic google search would reveal a full charged 12V lead is measures 12.6 open terminal.
Either the battery isn't being charged when the car is running or, more likely, the battery probably has a shorted cell.

Originally Posted by bmv335ie90

Okay thanks, I have replaced several batteries over the years and never have measure a voltage that high, usually 12.4 is typical for my new batteries. I am still leaning towards a failed battery based on the voltage drop when load is applied

Indeed. The voltage drop under moderately low load is indicative of high internal resistance. The battery is showing its age.

Originally Posted by mecheng77

When the battery is connected you will not read
12.6v, only if disconnected.
I read 12.2v on my fully charged battery connected. It is new.

Get a refund? IDK haha. Connected with no significant load is essentially the same as open terminal.
It's around 40F where I am, which decreases voltage by about .07V compared to 70F. Car has been sitting for hours. The battery is also is 2+ years old.

Temperature correct, my batt is 12.54. That's pretty decent.

[techwhiz]

Originally Posted by bmv335ie90

3. Next steps, remove battery and have it tested. Battery is from 10/14 so this could possible be bad. Battery is OEM Excide. I noticed that the battery drops a full 1.0V when waking the car. For instance, the battery measures 12.5V when car is asleep. I open the door and it drops to 11.5V and slowly increases back to 12.5V over the next 5-10 mins. This does not seem normal and could indicate a bad battery?

I would change battery.
AutoZone sells a compatible glass mat battery for about $200.

I had a similar issue where if I let the car sit for more than 3-4 days I'd have an error code and dead battery.

New battery solved the issue.

[juld0zer]

IBS/IGR enabled cars will only charge to 80% most of the time.

Does your car have comfort access?

[bmw335ie90]

First off, I wanted to say I really appreciate all the feedback. I'm glad this forum is active with people that want to help.

I removed the battery today and noticed quite a bit of battery acid underneath the battery. Either the drain hose wasn't connected or this thing was spewing a lot of fluid. I removed the battery, it measured 12.34V. Took it to two places that said the same thing, battery tested okay but was only at 60% charge. Both places (O'riellys and autozone) used a ganky handheld tester so I'm not so sure about that. I brought it to NAPA and they said they will charge the battery to 100% and perform a load test where they basically short the battery and measure the CCA and voltage drop. If it passes that test I will believe the battery is okay

Originally Posted by ewicky

I reread the thread and there is conflicting information. In part 3, you first state that you see 12.5V, which is good. Then later say you've never seen above 12.3.

12.5V was an arbitrary number i threw out, what I said is true about not seeing it above 12.3V

Originally Posted by juld0zer

IBS/IGR enabled cars will only charge to 80% most of the time.

Does your car have comfort access?

No comfort access.