Battery drain with test results..Please advise!

My car's battery indicator light started coming on/off intermittently this whole week. Then today, it came on and stayed on for longer periods at a time. Then, when I got off work and was about to drive home to enjoy the start of my weekend, my car didn't want to start. So I called AAA and they came to jump-start it. They ran some tests, and you can see the results in the attached images. Basically, the AAA guy said my alternator and starter are fine. The battery has been drained (only 492 CCA) but may still be good if it gets charged up again. The more important problem I have is that something is draining my battery even when the car is not on, or not in use. See the "Drain Test" in the 2nd attachment. It shows 1.04A, which I'm assuming is current that is being drained as the car sits there.

I read on here that there can be many causes: bad Final Stage Resistor (FSR), malfunctioning aftermarket devices such as stereos, DSP amp. Also, there seems to be some ways to test it, such as inserting a voltmeter at the (-) terminal, pulling fuses one-by-one, etc.

Well, I dont have any after-market devices or stereos hooked up inside my car. The only after-market component that I HAD until a few weeks ago were angel eyes. However, one side had not been working for months, so 2 weeks ago, I took them out, and removed their wiring inside the hood. However, I have NOT removed/disconnected the other end of those wires that go thru the firewall into the front cabin of the car. At the places where I cut them, I've taped the ends up with electrical tape. But I'd be surprised if this is the culprit for my battery drain...IS IT???

But anyway, the other thing I want to ask is how exactly do I go about performing the above testing methods? Do I still need to put in the voltmeter, or is that not necessary since I already have the "1.04A" test results? How do I do the fuse pulling test? Do I keep the car engine on, and just plucking out the fuses? Or do I pull one out, and put the previous one back in??

Sorry, I'm very bad with electronics/circuitry stuff...

I do not know exactly what a BMW parasite current draw would be, however, 1.04 Amps sounds a bit high. I would expect most cars to have about a 20-200 mA or 0.02-0.20 Amp draw when the car is off.

Pulling fuses is a go place to start, however. you will need a multimeter with a DC Amp setting, then you would typically remote 1 battery cable and put the multimeter in series with the battery cable. It a pinch you can use a 12 DC test light, it is not a precise indicator, but it will show you if you have found a draw and reduced it. Also keep in mind when doing all of this, trunk lights and interior lights can fool you if you have doors or the trunk open. The trunk lights can easily be pulled out. As for the interior light this should be as simple as closing the door. Also beware of the glovebox light when pulling fuses as well. This will be easier and quicker if you have a helper to watch the meter or test light.

As I recall BMW's modules do go into a sleep mode after quite a number of hours to conserve battery draw, however, even when they are awake, I would think 1 Amp seems a bit high?? Maybe someone with actual BMW data can give you an idea of how much current a typical BMW may draw when sitting.

Good luck.

You need to follow through with some parasitic draw tests. Here's one link, but you should search for more by Seth Thorson (jbeurotech) and others.

fsr

What is the normal current draw at the positive terminal of the battery when the car is off (and has been off for more than 15 min)?

I'm asking because I started doing the fuse-pulling test to find out where my battery drain problem is coming from. First, I measured the current before doing anything. My mulitmeter read "2.65 A". Only the trunk light is left ON as this time, since that's where the battery is. Then I started pulling a couple of fuses one by one (radio, DSC, heater, AC, fuel pump, fan) and the current did not change by any significant amount. When I got to the fuse for the "passenger comp/trunk light", it dropped greatly, to about 0.3-0.4 A. Now, is this the normal current draw? Or should it be lower? After this, I decided to put that fuse back, and disconnect the trunk lights, before further testing. Pulling out couple more fuses didnt change the current level much at all.

When I got to the fuses that were responsible for the diagnostic monitor and on-board computer, I noticed that the current dropped down to about 2.49-2.52 A. Is that normal?

I can't comment on what is "normal" as I have never tested a "known good" car, however, double check your last figure you posted regarding the diagnostic monitor and on-board computer as I think you may have you decimal point off or the suffix stated incorrectly?

Are you stating the diagnostic monitor and on-board computer is drawing about 150 mA?

Normal parasitic draw should not be more than 350 to 450 milliamps. Anything more than that, then something else is drawing current when it should not be. Also your tested CCA is about half of the CCA rated by the battery initial test, & that's if they initially plugged in the right CCA for the battery at the start of the test. 900 CCA sounds a little too high, S/B around 750 to 800 CCA. Either way the battery reserve is still a bit too low. Chas

jfoj:
Correct, the pulling out the diagnostic monitor and on-board computer fuses caused the current level to descrease by about 150 mA.

ChasCan:
That CCA reading you saw in the first pic I post is of my old battery. For the fuse-pulling test I've mentioned in my previous post above, I'm already using a new battery. Like I said, after disconnecting the trunk lights, my current level reading shows about 340 mA or so. So that's normal?

Read this link:

http://forum.e46fanatics.com/showthr...ighlight=sleep

JBEUROTECH knows what he is talking about.

Looks like the Final Stage Resistor may be a really common issue.

But you need to test the car in sleep mode which appears to happen after about 20 minutes.

My guess to do this correctly, you need to pull the trunk lights, leave the trunk open and connect the Ampmeter inline with the battery and they watch via the open trunk.

I think?? if you open up any doors or use the keyfob, you "wake up" the sleeping modules.

Originally Posted by jfoj

Read this link:

http://forum.e46fanatics.com/showthr...ighlight=sleep

JBEUROTECH knows what he is talking about.

Looks like the Final Stage Resistor may be a really common issue.

But you need to test the car in sleep mode which appears to happen after about 20 minutes.

My guess to do this correctly, you need to pull the trunk lights, leave the trunk open and connect the Ampmeter inline with the battery and they watch via the open trunk.

I think?? if you open up any doors or use the keyfob, you "wake up" the sleeping modules.

you don't need to remove the tail lights. just leave the trunk open.. the GM will shut down the car and interior lights after 15 min anyways.

battery light is probably the alternator. I would replace the voltage regulator and see if that fixes it. about $110 from your dealer.

I have a FSR problem and to tell it you have to get the car in a totally quiet place. You can hear it making a wailing sound up and down, like a ghost from scooby doo or something. You can feel air coming out of the vents, but just barely. Mine does it for 5 minutes quits, then starts up again at random. I could not hear or feel this until about the third time I looked. I had a drain of about .38 amps.

I am not having any big fan speed issues, just the battery draining. $58 plus shipping at Pelican.

I had a similar problem with battery drain
I measured the current - 400mA when car was sleeping
Removed fuses one by one - no luck, still draining

Finally I pinpointed the problem: http://realoem.com/bmw/showparts.do?...43&hg=64&fg=65 - flow heater electric

I disconnected it and I have no more drain now. Will have to look for a new part (quite expensive)
I do however have another strange measurement I took: I measure 29V AC at the battery while charging. I wonder how "normal" is this, or is there a problem with my alternator....... I do have fluctuating 13.7-14.2 DC so it's not that bad.

You need to check the paristic draw. The draw is only a valid number after the car has gone to "sleep" 16-18 min is what it takes to go to sleep. Test the draw then and let us know it should be 40MA or less. I am willing to bet you have a draw. If the autoparts store passed your battery it must be pretty good. Most auto stores test tools are "slanted" to sell you a battery. Just as BMW's tools are slanted to say the battery is ok........

Your alternator is toast. Guaranteed. I don't care who tested it or how they tested it, it's toast. Get a new one. www.alternatorpros.com

My E39 did the exact same thing. Intermittent battery light to steady battery light to dead battery. Your battery is also toast so be prepared to fork over for a new one. 49DL from Autozone. You can't run a battery down and expect it to form properly again.