Battery Light Of Death Options

[Drexus]

Of all the times for the alternator to stop working... So I start the car up to take the car out of storage and the battery light comes on. If I hook up a charger, the light goes off when I reaches 11.5V. If I then remove the charger, the car will slowly drain to 11.4 where the light comes on again. What the heck? It's not like I asked it to boost another car or something, I just want it to run the lights.

Has anyone had experience with this sort of thing? I've had lots of trouble with the electrical in the past (all under warranty) resulting the replacement of connections to the battery. But now, the battery light is on.

Suggestions?

[smart142]

What happens when you start it up?

[Drexus]

What happens when you start it up?

It runs. Then the light comes on. That's if I charge it for a bit first. If I don't charge it, it will start, but the light comes on at the beginning. It takes about 15 minutes for the light to come on from a full charge.

This post has been edited by Drexus: Mar 7 2010 - 01:52 PM

[smart142]

Sounds like you need a new altenator. If you're out of warranty that can be an expensive option.

[Drexus]

Sounds like you need a new altenator. If you're out of warranty that can be an expensive option.

I know. I'm hoping it's just a regulator that can be swapped out... I've dismissed the chance that it's bad wiring or something, so there's where I'm at.

[smartnhappy]

The weakest link in the charging system is the battery. Almost all electrical problems I've had with any type of vehicle over the years were traced back to the battery (barring a lose or worn alternator or generator belt).
If your car has been in storage, the electrolyte in your battery may have stratified (chemically separated and settled into layers), weakening it's overall performance and diminishing it's capacity to take and hold a full charge.
A good mechanic could do a simple load test with a good battery meter to confirm it's condition (and verify alternator output also).
I'd almost put money on a weak battery.

[Drexus]

The weakest link in the charging system is the battery. Almost all electrical problems I've had with any type of vehicle over the years were traced back to the battery (barring a lose or worn alternator or generator belt).
If your car has been in storage, the electrolyte in your battery may have stratified (chemically separated and settled into layers), weakening it's overall performance and diminishing it's capacity to take and hold a full charge.
A good mechanic could do a simple load test with a good battery meter to confirm it's condition (and verify alternator output also).
I'd almost put money on a weak battery.

So if I start the car with the battery and I disconnect the battery from that point, would the car not run a regular voltage? From what your saying, the battery is shorting out the system - preventing it from charging. If that's the case, why is it that I can still start the car after 2 weeks of sitting in the driveway without charging it? You're almost getting my hopes up.

[Mike T]

I could be wrong re: smart, but my 1966 car has a warning about disconnecting the battery with the engine running, something about burning out diodes in the alternator.....

[ianjay]

It is going to be much cheaper to replace the battery than an alternator. There are two ways to fix a car - throw parts at it and hope to bad stuff goes away, or try to have it properly diagnosed and repaired.

Since we seem to be favouring the former, the consensus seems to be replace the battery. Even if the alternator has a regulator that can be serviced/replaced, you're going to be in for the major job of getting to it. At that point, I wouldn't bother to do anything but replace the whole assembly.

The best battery on the planet will cost less than $200 and you sound like someone who can fit a thing or two. A smart is little different from any other vehicle - they don't like being stored. Batteries with weak cells can do all kinds of crazy things to an electrical system that is expecting all components to be working as designed.

I wouldn't risk running the car with the battery disconnected in any modern car.

[smartnhappy]

So if I start the car with the battery and I disconnect the battery from that point, would the car not run a regular voltage? From what your saying, the battery is shorting out the system - preventing it from charging. If that's the case, why is it that I can still start the car after 2 weeks of sitting in the driveway without charging it? You're almost getting my hopes up.

The battery might take a charge deeper from a charger than the car's alternator can do it, if the battery is marginal.
Don't disconnect the battery with the car running. You'll end up posting inquiries here about electrical problems you'll be having forever.

[The Easton Way]

Just replaced the alt. and drive belts on my 2006 cdi.
113k

Alt $452 +core of $87
Belts $30
Labour $286 (not MB)

Tough spot to get to, but location alt. takes a lot of road grime.
If you are going to test the alt. output hook another battery to the battery cables then test the voltage.
Load test will only test the battery. Replacement battery is about $160 in Ontario, Optima gel battery about $250

[Drexus]

Just replaced the alt. and drive belts on my 2006 cdi.
113k

Alt $452 +core of $87
Belts $30
Labour $286 (not MB)

Tough spot to get to, but location alt. takes a lot of road grime.
If you are going to test the alt. output hook another battery to the battery cables then test the voltage.
Load test will only test the battery. Replacement battery is about $160 in Ontario, Optima gel battery about $250

Are you saying the core charge is in addition, or they subtract the cost of a core? (since they will be taking the old one).

[lebikerboy]

Don't know where you're getting a price of $250.00 for the Optima.
Costco (cheapest), Walmart sell for less than that...

[Fred J]

Are you saying the core charge is in addition, or they subtract the cost of a core? (since they will be taking the old one).

A core charge is only applied to a rebuilt component to have you return the used part so it can be rebuilt and the cycle continues. You get the core charge refunded to you.

If it is a "new" component (as verses a rebuilt one) such as a dealer supplied o.e.m. part, there is no core charge and you own the old part outright. Do with it as you please, but remember it has residual value for you.

[bilgladstone]

I may be wrong of course, but I highly doubt they will take the dead alternator back for rebuilding. you could do a minor rebuild yourself if it is just corroded or the brushes are finished. Or have a rewind shop do a complete rebuild.

Then you could keep it for future repair to your car, or sell it on to someone who needs one.

FWIW,
Bil

[Drexus]

I may be wrong of course, but I highly doubt they will take the dead alternator back for rebuilding. you could do a minor rebuild yourself if it is just corroded or the brushes are finished. Or have a rewind shop do a complete rebuild.

Then you could keep it for future repair to your car, or sell it on to someone who needs one.

FWIW,
Bil

Well, that was expensive. It seems the battery was damaged due to the alternator leaving it to fend for itself. I had to buy another battery just to drive it to the dealer. $190 later and I had the right battery in the car. I didn't even charge it. I drove the car 65 km to the dealer, at night, with the lights on, and the voltage dropped from 12.1 V down to 11.6 in that distance. The battery light didn't even come on. Mostly because I picked up a battery from UAP/NAPA with a rating much higher then the one I took out. I think the OE battery was 550 amps, and the new one was 650 (I think). In any case, the car used nothing so far as electrical power. Makes you wonder what the alternator is for.

[ETHICAL BEEF]

O.K. Dawn's 2005 came out of storage this week and has the very same symptoms as the one Drexus mentioned here.

Had to charge the battery up to start it initially. Battery light came on tried to make it back home but the 3 bars of death came on.

Put in a brand new battery from Smart today. Thought it was cured but after about driving 15 K's the battery light came on again. Made it back home but not before a bunch more of the dash lights came on. Tried to restart right after we shut it off. Battery totally rundown.

Let it sit about 3 hours and tried to start it up again. Fired up like a brand new battery and no sign of the light on until the car had run about 5 more minutes.

Seems like a faulty regulator otherwise the battery light should come on immediately.

Looks like were in for a trip to MB??

Any other suggestions?

Thanks James & Dawn

[SMARTING]

I just went through much the same scenario James. Smarting was parked for the winter. I would fire it up every now and again and let it warm it up, but I guess that wasn't enough. When I started it to bring it out of the garage I left it idling and after a few minutes everything just went quiet. Hmm. I tried to restart to no avail. The engine would crank like mad but would not fire. The car went by ambulance to Mercedes in London where the battery was replaced and they discovered a "rotating resistance" in the alternator. I don't know if the alternator resistance could be chalked up to lack of use over the winter causing some corrosion or not, that seems a possibility. Anyhow everythings good again I'm just a little poorer.
Terry  IMG_2386.JPG ( 1.93MB ) Number of downloads: 14

[Mike T]

Ack, bummer! Was that car ever winter driven, Terry?

[Albertaaw]

For each winter since we got DR MAP in April 2006, he has been covered up in the garage, minus his battery. The battery was taken out and stored in a warm spot in our basement. After being idled from around mid-November to March 25th, Cliff put the battery back in with the help of Glenn. The battery was recharged outside of the car before being reinstalled. DR MAP has run fine since then. We'll hope that continues!