Battery light comes on intermittently
 

It started happening yesterday. Sometimes when I'm driving the red battery light comes on for a few seconds then goes away.

I should mention that the battery seems OK because the car always starts normally with no hesitation. Someone told me it could be the alternator.

Any ideas?

Okay now the light is coming on more often and for longer, but still goes out after a while then comes back on.... Starting to get worried...

Any ideas???

Its the begining signs of telling you that the alternator is about to go out. Get it looked at and mention that. If you keep going its going to shut off while you're driving and you'll have no power in the middle of the highway or road..take your pick.

what happens if the power goes out while I'm driving? Won't the battery last a while?

get your battery check immediately, check voltage on alternator as well. you dont want to be in the situation we (me and my wife) were. she was left stranded on middle of I-95 when everything shuts down. she told me it was scary experience. the thing just shut down, i mean everything. she was lucky enough to pull over the shoulder of high speed traffic I-95. thats because in the morning she forgot tell me that the battery light is on, she took it to work and on the drive home the alternator died and the batter is gone too, that causes the whole thing to shut down. drive carefully.

wow, that is scary... i'll have it checked out right away, although I've been driving it and everything seems normal... engine powers up with no hickups so I know the battery is (still) good.

What sucks is that the warranty ran out last month!

Battery won't be good for long. Trust me..That thing's gonna be dead in less then 5 days..And if you're lucky, it won't die while your driving..I'd be surprised if it lasted that much longer. In fact, I wouldn't drive it at all. If you do have to drive it, I'd drive it strait to the shop and nowhere else.

I had this problem, my light is still on, changed the voltage reg. The light is still on, I checked the charging rate and it is 14volts. I have run out of idears now

after I installed a new alternator the light kept coming back on. had to take it to the dealer where they reset something.

Did you check and clean the contact surfaces for wear before you replaced the regulator?
Replacing just the voltage regulator won't solve the problem if there is an open circuit in the positive/negative or exciter diode.
You will have to replace the alternator if these conditions exist.
Get the alternator tested or if you have access to an oscilloscope, check it yourself.

As far as a reset, our resident BMW technician could tell you more on whether it is just to clear code using a generic OBD11 or if has to be on GT1/MoDIS.

I took the alternator to a place which re -cons them, they checked every thing out and said the regulator was faulty. I have run carsoft and my bmw scanner and have no fault codes.I cleaned the wires which go to the alternator aswell.

OK i just got back from the dealer... took it for a test drive and the light came on a few times. While driving, the technician entered the hidden diagnostic menus (by pressing and holding the right button that produces "CONTROL CHECK OK"), and he went into one setting that monitors the voltage. The voltage was steady between 12.8 and 13.1 which is normal, and even when the battery light came on, the voltage held steady. So the battery is OK even after 5 days since the problem started. I need to take it back for a more thorough check of the alternator. But on the 45 minute drive home, the light didn't come on at all, and the only difference was that I had the headlight switch on 0 instead of A (i always had it on A)... coincidence? Strange.

Comments?

Hi i dont think that a voltage of 12.8 to 13.1 is normal the float voltage for a lead acid battery should be at least 13.4 your voltage regulator is not correct to me.If you add more loads ie. foglights high beam etc.what does your charging voltage read?

12.8 is normal UNLESS the engine is running. alternator should produce 13.x - low 14V.

Well, it was between 12.8 and 13.1 most of the time, and when I turned on the xenon headlights, the voltage stayed at the same levels. The service advisor told me that the normal range is between 12 and 14. It shouldn't be under or over.

That does seem low to me... with your 170 amp alternator you should load test it with a carbon pile tester (puts physical load on the system, test in live conditions) If the local dealer only has the new "smart" electronic impedance testers it may be giving inaccurate readings by not putting a real load on the battery. I'd go to a shop with the old school VAT 40 load tester and have them test the system. Load test the battery at the battery posts at 1/2 the cca reading for 15 seconds... the voltage shouldn't drop below about 10.2 volts. Load test the alternator from the jumper points under the hood at 170 to 180 amps with the engine running at about 2000 rpms and you should get at least 180 amps. I've had cars in the past that tested great when cold, but after driving it for an hour the alternator wasn't charging for shit... could get weaker as you drive as well...

Im having the same issue now with my X. Battery light flashes briefly for a period of 5 minutes or so. Doesnt stay lit. No trouble starting. No dim dash lights or anything.

Just had my alternator replaced about two months ago. When I realized it was dying (all dash lights came on) and I was trying to make it to the shop, the battery died all the way when i stopped for gas and shut off my X like a dummy (thought i'd be saving battery energy). I had to get a jump in order to drive the final two blocks to the garage.

Did this "kill" the battery? Like I said, it still starts like normal, no extra straining or anything.

I went to RS Strauss and had the battery tested. It was 10.78 volts with the car off and 13.8v with the car running. From what I'm reading, I need a new battery. Right?

Battery Voltage
 

If the car is not running, the battery should read a minimum of 12.6. Otherwise, it means that one of the cells is dead. There are 6 cells, minimum voltage should 2.1V per cell * 6 = 12.6V.

If the car is running, you'll see voltage from the alternator, which should be putting out a healthy 13.7ish Volts. That just means your alternator is working fine. It doesn't mean the battery is still good.

If the battery won't accept the higher voltage, then one or more of the cells is bad and it's time to get a new battery.

Match group for your new battery, or alternatively, match Cold Cranking Amps (CCA), but make sure your battery hold down system will fit properly, and don't cheat and not hook up the battery fluid overflow hose.

Thanks for the wealth of information and :welcome: to Xoutpost!!
I didnt know what you meant by matching the group and I'm not sure what the CCA's should be although I'm sure they can tell me in the store.

I promise to hook the hose up and ensure proper fitment that it will be held down correctly.

Group Sizes and Cold Cranking Amps (CCA)
 

Group sizes is the battery industry's meaningful way of designating size (like AA or C size batteries) and the way that battery connections are made, (top, side) and the internal volume of the battery. Cold Cranking Amps is how many amps the battery will discharge at various temperatures.

To match the battery exactly, you need to match or exceed the size (volume) and cold cranking amps.

I went to www.interstatebattery.com to find the correct fitment. Typically an V8 X5 OEM battery will be closest to one of these.

Here are the specs on for two batteries:

Product ID:
MT-49(Automotive Truck)Amps:940Cranking Amps:940Cold Cranking Amps:750Voltage:12Termination:APro-rata Warranty:75Weight:43.3Width:6.88Length:14.38Height:6.88


Product ID:
MTP-93(Automotive Truck)Amps:1000Cranking Amps:1000Cold Cranking Amps:850Voltage:12Termination:APro-rata Warranty:85Weight:43Width:6.88Length:14.38Height:6.88

You will note that the batteries have different group sizes, but are actually quite close in specs, and the only differences are weight, the heavier battery puts out less voltage, and has a shorter warranty months. I would compare pricing and divide by the warranty to get cost/month.

Size is important because there is a battery hold down system (that keeps the battery in place), which might not fit a smaller or larger battery, but it if puts out enough CCA, it will work fine. Costco is a great place to buy batteries because they are priced inexpensively for the warranty months, have such a great return policy (100% replacement up to 36 months), assuming you can find one that fits or can be held in place.

Don't buy the BMW OEM battery. Overpriced and probably similar quality. (my $.02)

BMWs with their usual rear end battery location have some way to overflow excess fluid during overcharging (typically they don't as they have a charging regulator), usually that is a tube that leads to an exit point. If you don't use the tube, you might have sulfuric acid in your battery tray...not a good thing, but that is a safety factor.

Hope this helps.

absolutely! You are a welcome addition to the xoutpost family! Thanks a bunch. Will let you guys know what happens.

Ok so I went to Strauss (because I went to like 3 Pep Boys and 3 Autozones who didnt have the size) and got the battery for $105.00. When I went to install it, there was a pool of standing "water" around the existing battery (was Kirkman brand from Costco). It was a good amount, maybe 3/4 cup. So I took the battery out and noting that the overflow hose wasnt hooked up.

I'm sure you guys can figure out the rest of the story, right? I start sopping this "water" up with a rag and my skin starts tingling. Then I realize it's acid and I'm trying to get it off with some windex I had in the trunk. Worked for about 30 seconds then my arm really started to burn. I ran in the house and got some sweetened condensed milk out the fridge (I'm lactose intolerant, dont have regular milk in the house) and start slathering it up and down both arms which are both burning at this point.
Well thankfully I like to make stuff that requires sweetened condensed milk. Anyway, that worked and I went back outside to finish.
Anyway, after almost eating myself alive, I manage to get the new battery installed.

When I first started the car, the brake light, battery light, ABS light and the little yellow triangle in the center all illuminated. I'm like "here we go" but after driving around the block, all the lights except the battery light went out.

Well it went out but it was flashing intermittently. Took it to the mechanic today since I needed an inspection sticker and they checked it out with their mechanic vehicle charging system checker. I watched them and the tester said battery and charging system was fine.

So I took the X and left and of course it didnt flash in front of the mechanic but its flashing now.

Any ideas anyone?

I got the same issue. Just replaced the battery and I have the battery light on at all times.

check the alternator. mine did this a month ago.

Yup, looking at an alternator now. Put a meter to the battery post while car idle and reading is 11.8, 12.1 with car off. No output from Alternator.

Is this true? Is 13.7 Volts a target voltage while car is running? Can someone please verify this?

Weird... I got the following email... but when i came to this particular thread, nothing...

Reply to thread 'Battery light comes on intermittently'

Monday, February 7, 2011 10:04 PM

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"Xoutpost.com" <[email protected]>
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Dear Ldiggs910,

lemon has just replied to a thread you have subscribed to entitled - Battery light comes on intermittently - in the X5 (E53) Forum forum of Xoutpost.com.

This thread is located at:
http://www.xoutpost.com/bmw-sav-forums/x5-e53-forum/58122-battery-light-comes-intermittently-new-post.html

Here is the message that has just been posted:
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I've had my 2007 X5 for 3 days and the battery light is on.... Also the phone settings were missing one time I started her up and the the radio settings were missing the next.

The battery light did flash when I test drive it but the dealer said it would charge when I drive it... Everything was fine until tonight.

Is this the alternator?

I have a certified pre owned so there is a warranty.
***************


There may also be other replies, but you will not receive any more notifications until you visit the forum again.

All the best,
Xoutpost.com

Maybe he deleted the post once he realized how old the thread was...

whats great about these threads is how they're still useful no matter how old they are. BUt on second thought I guess he realized he posted a question about his e70 in the e53 forum

Where Is the Alternator? Can somebody take a picture of it? And how do you check if it is working properly? Sorry for the Stupid questions?? My light is coming on and it goes off for a while and them comes back!! Grr

Pls. Help!!

It is under the hood. To test it you take it to a shop that has the proper equipment to test both the battery and the charging system. If you don't want to take it to the dealer, take it to an independent shop.

Thanks JCL
I went out to the STEALER and purchased a $230 battery and It didn't fix my problem so I know the Battery is good, But I put it on a trickle charger just to make sure the battery wasn't drained from the dealer.
But after reading this thread I am thinking I may have an Alternator issue!!

I would like to do this my self any idea on the level of difficulty?

Sooo. I realize I didnt report back on this thread and thats because the problem really wasnt fixed until just this past month.

This is ultimately what occured but I'll kinda start from the beginning.

1. One day my alternator simply stopped charging the battery.
2. When I realized it I was on my way to work which is 20 miles away from my mechanic.
3. I basically drained an already old battery (which also was leaking apparently) all the way dead on the way to the mechanic
4. He replaced the alternator with some random aftermaket brand because that was what my aftermarket warranty company was willing to pay for.
5. The battery light continued to flash intermittently after the alternator was replaced.
6. I replaced the battery thinking because it was leaking it was defective (that wasnt necessarily true because it was still charging up fine, its just the light kept flashing).
7. This past March I had a DIFFERENT mechanic look at it and he says its the alternator.
8. I told him it the battery charges fine and he acknowledged that the charging/electrical sytems/voltage WAS correct but that it was the alternator.
9. So the warranty company AGAIN pays for the replacement of the alternator only THIS time he uses a Bosch brand alternator.
10. After over a year of battery light flashing, my problem is gone.

I updated this thread because I've been helped so many times by "old" information and I figured somebody might be having this very issue

I replaced my alternator 3 months ago. 4.6is liquid cooled
no troubles, no lights since then. battery light came on again yesterday, intermittently then solid, then off 100km later and now on again around town.

faulty alternator or voltage regulator? is there a way to test the voltage regulator?

Ok...I am trying to reactivate this dead thread.

On my 05 E53 I have replaced my Battery as part of regular maintenance about 2 months ago. It was over 3 yrs old.

I have since replaced Crankcase housing and Oil filter housing gaskets. Everything worked out perfect. A month and half after the above jobs the Battery warning light comes on intermittently. The night before I drove while there a heavy poring rain. I checked the under the engine for the plastic oil catch and metal plate. Looked OK except on the metal one there were two opening. Not sure if it is like that or or Inde idiot that worked on my X5 forgot to put it back or worse STOLE it. Sorry for being mean.

So my question is due to the rain and condition below the engine contributed possibly for the alternator or the voltage regulator going bad?

Your thoughts appreciated.

I'm guessing you're about to lose your alternator. I got the intermittent battery light a few times before the alternator totally took a dump and stranded me.

Missing access hole covers in the stiffening plate - I don't think that's a big deal. My car was like that when I got it 2 years ago (and still is) and I'm not concerned. Very doubtful that it would be related to your alternator problem.

When the alternator on my '01 3.0i went out (VALEO 120 Amp alt), the charging light would come and go intermittently for a very short window until it died completely. Turned out this was the more-worn of the two brushes finally wearing down enough to lose contact with the slip ring.

On my alternator, the brushes assembly is part of the Voltage Regulator. At the time, I could not wait to get all the parts (bearings, slip rings, etc.) for a more complete rebuild, so I just replaced the Voltage Regulator. That's where I would start looking if I were you. If that is the problem, clearly neither rain nor open access ports had anything to do with the failure. It's just normal wear. Mine went at around 170k miles, which I think is typical for those cars/alternators.

:thumbup:
Thanks Fifty150hs.. I will replace or rebuild the alternator. May be replace voltage regulator too while I am there. Appreciate your thoughts

:thumbup:
Thanks oldskewel for your insight. The reason I got that doubt about the open access ports was because I saw splashed rain water all over under the hood and I see the battery warning light flash the very next morning of a heavy rain.

I am ordering voltage regulator and thinking of having the alternator rebuilt. But if I decide to go with a new one I may go with a Bosch. But not sure about the difference between 120 Amp and 140 Amp for my '05 X5. Will do some reading on this.

Thanks again...