Batter Light On Need Help/Advice - BMW Forum

Redbullrr · 06-19-2006, 07:32 AM

Ok, so I was at the beach, and when driving there I noticed that a light in my Cluster witch appears like a battery was on, but very dim. I didnt pay much attention, thinking there was a glare (it wasnt bright enough to appear on). When leaving the beach all my ABS light and Traction Control Lights turn on and the Battery Light lits up. Suddenly my Climate control starts flickering and my RPM Gauge is going up and down. The car then shuts down completely. I tried to start her up and she sounded like weak like there was no power. I went and borrowed a friends battery just to get home. The car turned on now problems with the lights flickering however I still have this Battery light still on yet very very dim.

Does anyone know what the heck this is? Do I have a bad alternator or do I just need a new battery?

drz · 06-19-2006, 11:16 AM

Have the battery tested at a local auto parts store. Also have the alternator tested. If both pass, I suspect that your voltage regulator is out. The thing is, the voltage regulator -- if bad -- will start failing once it warms up, so it would take a few minutes of driving before you see the warning light.

If your voltage regulator is bad, I recommend that you get a whole new alternator (regulator is internal to the alternator), since the rest will likely go bad in the near future anyways.

Good luck

Redbullrr · 06-19-2006, 11:23 AM

Hey thanks for the response. Going to get that tested and let you know.

polaris448 · 06-19-2006, 12:35 PM

that is a classic sign of a bad alternator. i have blown a ton of them in an old crx because of have a huge system that used 75% of the output. the best part of the whole alternator probs. was that i only bought one and got five free. napa's replacement policies are usually no questioned asked plus i can change that crx one out in about 25 min. now.

Redbullrr · 06-19-2006, 12:42 PM

Thats funny, dam I think I know what happened then... When putting my suspension back to OEM, and putting my rims on over the weekend. I had the system playing while the car was off. Could this F up my Alternator?

Gator · 06-19-2006, 12:50 PM

"I had the system playing while the car was off. Could this F up my Alternator?"

I shouldn't hurt the alternator, but it could have easily kiled the battery.

Redbullrr · 06-19-2006, 03:04 PM

So how the F does the alternator just go bad like that. I dont get it. Dam sensitive shit.

polaris448 · 06-19-2006, 03:41 PM

the low/bad battery could have caused the alt. to go to hell. by sytem i mean subs. and/or aftermarket amps. the stock sytem or even another headunit would not run a battery down even if it were on for hours, imo.

Redbullrr · 06-20-2006, 07:30 AM

Yeah I have a system 1000 watt amp Box Infiniti Speakers Yada yada. Took the alternator to Autozone to test and it failed. Bought one from them with lifetime warranty for 225. Not bad huh?!

drz · 06-20-2006, 10:23 AM

Quote:

Originally Posted by Redbullrr

Yeah I have a system 1000 watt amp Box Infiniti Speakers Yada yada. Took the alternator to Autozone to test and it failed. Bought one from them with lifetime warranty for 225. Not bad huh?!

Not bad at all. I also got mine from them.

I don't think your alternator just went bad from that one particular day. They just deteriorate over time. Our cars are all pretty old, so things like that are not rare.

Be sure to have your battery tested. If it is not holding charge, then it will continue to strain your alternator.

Redbullrr · 06-21-2006, 08:07 AM

True, thanks for the input.

Redbullrr · 06-22-2006, 07:26 AM

Got to say that was by far a real easy install.

bitcore · 06-24-2006, 12:46 AM

Quote:

Originally Posted by Gator

"I had the system playing while the car was off. Could this F up my Alternator?"

I shouldn't hurt the alternator, but it could have easily kiled the battery.

Yes, the battery would get damaged. Then the alternator will have to charge that battery back again. When the alternator is faced with charging a dead battery, a tremendous load is palced on it. If I leave my music on (stock system) on low volume for about 20 minutes when I do work on my car, the belt will slip on the alternator's pully because it's demanding so much from the engine to charge the battery. It's rough on the whole electrical system.

If your alternator fails, you replace it, but do not trickle charge your battery, you may find that your brand new alternator will be dead within the week. It's happened to a couple of guys here or on BF.C

This problem is even worse if you stop your engine and run the music for 5 minutes or more frequently. Batteries are not designed to have extended 'deep cycles', as they are called, where they are drained very low and re-charged again. This action electroplates the zinc and copper plates in the battery, diminishing it's capacity to store and deliver electrons. Deep cycle batterys help with this problem, but do not eliminate it and do not have the capacity of standard car-batteries. (they are very bad for sound systems, they can't deliver the same amount of CCA [cold cranking amps: ability to dump a very large amount of instentanious power instead of delivering a small amount of power over a longer period of time, IE: big bass burps require lots of instantanious power] that a regular battery would, and nowhere near a gel battery like optima)