No lights, no crank, totally dead -- relatively new battery, <20K miles, please help!

Last time I drove my car was Monday coming home from work. Everything was fine then.

It sat in the garage Tuesday and yesterday since I took my motorcycle to work, and this morning I try to start my car and it's totally dead. I noticed that the window didn't roll down slightly (as normally happens on coupes when you open the door), there are no lights on the dash, no interior lights, and although I was able to open the the trunk, it doesn't latch when I close it.

Very worried about this. The car is a 2006 ZHP coupe, not even 20,000 miles on it, with a new battery I installed about 4.5 months ago when the OE one was starting to get weak. (There's a short post about that here)

What could be wrong with it? I checked the battery connections and they seemed fine, although I didn't undo any of the nuts for a closer inspection. I've had it on a battery tender since this morning (~13 hours) and it there still seems to be no sign of electrical life in the car.

Would love to get some ideas for where to start troubleshooting...

I did spot a connector that didn't have an obvious place it was disconnected from. Please see attached picture. Anyone have any idea what it goes to?

circled wire is for tilt sensor(i think) but if battery is charged clean post(even if they look clean) and tighten the crap out of the wires to the battery it may not be sending enough juice because of connection(happened to me as far as starter not working) but various other things worked at the same time.
gl

Originally Posted by dekaliber

Last time I drove my car was Monday coming home from work. Everything was fine then.

It sat in the garage Tuesday and yesterday since I took my motorcycle to work, and this morning I try to start my car and it's totally dead. I noticed that the window didn't roll down slightly (as normally happens on coupes when you open the door), there are no lights on the dash, no interior lights, and although I was able to open the the trunk, it doesn't latch when I close it.

Very worried about this. The car is a 2006 ZHP coupe, not even 20,000 miles on it, with a new battery I installed about 4.5 months ago when the OE one was starting to get weak. (There's a short post about that here)

What could be wrong with it? I checked the battery connections and they seemed fine, although I didn't undo any of the nuts for a closer inspection. I've had it on a battery tender since this morning (~13 hours) and it there still seems to be no sign of electrical life in the car.

Would love to get some ideas for where to start troubleshooting...

I did spot a connector that didn't have an obvious place it was disconnected from. Please see attached picture. Anyone have any idea what it goes to?

This is an obvious question but did you leave the lights on or something to drain the battery?

The battery might be new but you should have it load tested again if the tender can't bring it back to life. A tender is very slow in charging but after 13 hours there should at least be some sign of life. If the battery is toast then the next step would be to look for what killed a relatively new battery? Does the case look swollen?

Why do you have a battery tender? Do you store the car for the winter hence the low mileage? The battery tender should have protected your battery unless you actually have a battery charger and not a battery tender.

Originally Posted by ckleung100

This is an obvious question but did you leave the lights on or something to drain the battery?

The battery might be new but you should have it load tested again if the tender can't bring it back to life. A tender is very slow in charging but after 13 hours there should at least be some sign of life. If the battery is toast then the next step would be to look for what killed a relatively new battery? Does the case look swollen?

Why do you have a battery tender? Do you store the car for the winter hence the low mileage? The battery tender should have protected your battery unless you actually have a battery charger and not a battery tender.

Just took the battery out of the car. Contacts looked clean, didn't look swollen as far as I could tell. It's an Exide-branded OEM replacement, which has the indicator on top. That showed black, which I believe means that the charge is inadequate. I hooked the battery tender up to the battery directly and will leave it overnight to see what happens.

I have 2 battery tenders -- one for my Z4M and the other for my motorcycle, both of which don't get used during the winter months. They are definitely Battery Tenders and not chargers -- this model from Amazon.

I generally leave the headlights on "auto" or "off". In auto mode it would turn off once the key is removed. I never mess with the interior lights. The mirror lights should be off once they're flipped up (and they always are after I'm done driving). No reason for the trunk lights to be on since the trunk was closed. I can't think of any light that could have been left on unless some other mechanism failed and the light was obscured (e.g. visors, glovebox, trunk).

The ZHP is my daily, and I do live fairly close to work so the commute is only about 10 minutes each way. However I do make it a point to take it on at least one long trip that usually involves a highway trip each week.

I should mention a pulley started squeaking in the front and I haven't had a chance to investigate it closer. It seems to have largely subsided as the weather has gotten warmer, but I suppose the alternator is certainly a culprit.

Originally Posted by dekaliber

Just took the battery out of the car. Contacts looked clean, didn't look swollen as far as I could tell. It's an Exide-branded OEM replacement, which has the indicator on top. That showed black, which I believe means that the charge is inadequate. I hooked the battery tender up to the battery directly and will leave it overnight to see what happens.

I have 2 battery tenders -- one for my Z4M and the other for my motorcycle, both of which don't get used during the winter months. They are definitely Battery Tenders and not chargers -- this model from Amazon.

I generally leave the headlights on "auto" or "off". In auto mode it would turn off once the key is removed. I never mess with the interior lights. The mirror lights should be off once they're flipped up (and they always are after I'm done driving). No reason for the trunk lights to be on since the trunk was closed. I can't think of any light that could have been left on unless some other mechanism failed and the light was obscured (e.g. visors, glovebox, trunk).

The ZHP is my daily, and I do live fairly close to work so the commute is only about 10 minutes each way. However I do make it a point to take it on at least one long trip that usually involves a highway trip each week.

I should mention a pulley started squeaking in the front and I haven't had a chance to investigate it closer. It seems to have largely subsided as the weather has gotten warmer, but I suppose the alternator is certainly a culprit.

The squeal may be the alternator. Mine started to squeal for a while before it died.

I have had problems in the past using a tender or an "electronic charger" to revive a COMPLETELY dead battery. Because of all the electronic fail safes with these chargers, they don't start charging until they verify that they have been hooked up properly. With a totally dead battery, it doesn't have even a little bit of current to tell the tender the polarities haven't been reversed so it never starts charging. I had a battery hooked up for two days with nothing happening so I thought the tender was defective. When I took it back to the store, they hooked it up to a normal battery and the tender worked fine. Lesson learned and I dug out my old trickle charger to recharge the dead battery.

The next mystery is what completely drained the battery but if the battery was already weak from a faulty alternator, I suppose even the clock, radio, etc. would be enough to finish draining it. I would check the glovebox and trunk lights too. My car had a faulty switch that kept the glovebox light on.

Originally Posted by ckleung100

The squeal may be the alternator. Mine started to squeal for a while before it died.

I have had problems in the past using a tender or an "electronic charger" to revive a COMPLETELY dead battery. Because of all the electronic fail safes with these chargers, they don't start charging until they verify that they have been hooked up properly. With a totally dead battery, it doesn't have even a little bit of current to tell the tender the polarities haven't been reversed so it never starts charging. I had a battery hooked up for two days with nothing happening so I thought the tender was defective. When I took it back to the store, they hooked it up to a normal battery and the tender worked fine. Lesson learned and I dug out my old trickle charger to recharge the dead battery.

The next mystery is what completely drained the battery but if the battery was already weak from a faulty alternator, I suppose even the clock, radio, etc. would be enough to finish draining it. I would check the glovebox and trunk lights too. My car had a faulty switch that kept the glovebox light on.

Thanks a lot for your input. You're right about the Battery Tender not being able to charge totally dead batteries. I dug up the manual for it and it indicated that anything with less than 3 volts will not start to charge because of internal safety circuits. However, I am led to believe that this is also signaled by an indicator light pattern. Per the manual:

Red light flashing -- The red light flashing indicates that the battery charger has AC power available and that the microprocessor is functioning properly. If the red light continues to flash, then either the battery voltage is too low (less than 3 volts) or the output alligator clips or accessory rings terminals are not connected correctly

Guess I'll check again in the morning, but suppose I'm unable to charge it with the tender and don't have another battery charger, what would you suggest as being the best way to try charging it back up?

I guess I could try to take it to the place where I got the battery to see if I could take advantage of the 20 month free replacement. Not really sure how that works and under what conditions they'd actually give me a new battery on the spot, though.

I guess I could try to take it to the place where I got the battery to see if I could take advantage of the 20 month free replacement. Not really sure how that works and under what conditions they'd actually give me a new battery on the spot, though.

Take it back to where you bought it. I'm sure they will try to recharge it and test it. They obviously cannot load test a dead battery so they will usually trickle charge it first and then load test it. After that, they will tell you if you need a new battery or not. That will solve your battery problem. They will usually give you a new battery in the warranty period unless the battery looks abused ( cracked case) or over-charged (swollen, leaking, cracked case). If you want a free battery, deny everything...

Your next step will be to figure out what drained the battery.

If your alternator went bad somewhere on the way to work you would have likely seen the battery light come on. I suppose this could be a bad light but not likely. If the battery isn't old, return it and get a replacement under warranty. It's not common but it could be a bad battery. Then have your alternator tested. Good post on that in here somewhere.

Thanks guys. I do appreciate the feedback. So an alternator going bad is generally indicated by a warning light? I definitely noticed no such thing when I last drove it on Monday.

Next steps:
- Put battery into car in the morning after leaving it on the Battery Tender all night.
- If still no signs of life, I think I can safely deduce that the battery is 100% dead or defective, and therefore cannot be charged with the Tender.
- The auto parts store where I bought it opens at 7, so I'll drop it off first thing in the morning, have them try to charge it and determine its health.
- If bad battery, hopefully they can give me a new one on the spot (vs. having to order one and waiting)
- If battery is good, I'll pop it back into the car and try to start it.
- If the car still doesn't start, is it safe to assume that the alternator is fried?
- If the car does start, I'll take it to AutoZone to have them do some more thorough diagnostics on both the battery and alternator. In the meantime I'll try to find where a potential leak might be.

Originally Posted by dekaliber

- If the car still doesn't start, is it safe to assume that the alternator is fried?

The car will run with either actually.

It's need the battery to start the car but after it starts, the alternator takes over and you can actually disconnect the battery. That's why you can jump start a car.

A car can run on the battery only but not for long without the alternator to recharge it. You should get warning lights if it is the alternator.

There is a chance it was a bad battery but it's still a good idea to get the alternator tested either way though so it doesn't kill the new battery assuming you get one.

Originally Posted by Y2K_Bimmer

If your alternator went bad somewhere on the way to work you would have likely seen the battery light come on. I suppose this could be a bad light but not likely.

Hence the need for a Check the Check Engine Light Light.

Fortunately, after a night of charging outside of the car, signs of life returned once I put the battery back in. A slight spark from the negative terminal (which I connected 2nd) and then the trunk lights came on. I was able to work the windows and shut the trunk. I fired the car up and everything seemed fine again. No lights on the dash warning about alternator malfunction.

I turned off the car and sat in it with all the lights off in my garage so it was pitch back. I wasn't able to find anything that was on that shouldn't be -- The cabin lights went off after about half a minute, I had popped down one of the folding rear seats and saw that the trunk lights were both off, I played with the glovebox light to make sure that the switch to turn it off was activated at some point before the door latched shut. The only sign of electrical consumption was the flashing red light next to the business CD, which I think is normal, and that can't be much.

Since the weather is clear today, I think I'll take my bike and let the car sit on the tender all day to see if I can't get it to charge fully. Once I'm working with as much battery as possible, I'll hit the road tomorrow and try to get both the battery and alternator tested at Autozone. I read somewhere on here, I think, that they should be able to test both without removing them from the car.

In the meantime, I guess I should probably hook the tender up every weekend to top off the battery just to make sure that it doesn't run low again. What's weird is that, with my last car ('07 Z4), despite similar short trips to work, I never ever had any sort of unusual battery drain issues.

By the way, is there a way to tell the alternator output from the instrument cluster diagnostics?

From the wiki, it looks like function 9 will tell you the battery voltage, but I'm curious if there's a way to see what's being output by the alternator as well.

(I suppose I should finally buy a voltmeter/multimeter.)

Originally Posted by dekaliber

By the way, is there a way to tell the alternator output from the instrument cluster diagnostics?

The battery light goes on if there is a problem

Originally Posted by dekaliber

(I suppose I should finally buy a voltmeter/multimeter.)

Don't bother because it cannot be used to test the starting capacity of the battery. You need to do a load test which a multimeter cant do.

Originally Posted by dekaliber

The only sign of electrical consumption was the flashing red light next to the business CD, which I think is normal, and that can't be much.

Since the weather is clear today, I think I'll take my bike and let the car sit on the tender all day to see if I can't get it to charge fully. Once I'm working with as much battery as possible, I'll hit the road tomorrow and try to get both the battery and alternator tested at Autozone. I read somewhere on here, I think, that they should be able to test both without removing them from the car.

In the meantime, I guess I should probably hook the tender up every weekend to top off the battery just to make sure that it doesn't run low again. What's weird is that, with my last car ('07 Z4), despite similar short trips to work, I never ever had any sort of unusual battery drain issues.

They can test the alternator on the car. Not sure about the battery because that machine usually isn't portable.

You shouldn't have to hook up the tender every weekend if everything is working properly although infrequent short trips only won't give enough time for the alternator to fully recharge the battery.

Took it to Autozone earlier today. The guy said that he couldn't test the alternator because the battery isn't in the front, but he did test the battery with this large handheld device -- probably just a glorified multimeter, as far as I could tell. This seemed wrong to me, but I didn't know what I could do.

Anyway, he input the CCA spec into the device and read the voltage. With the car off it was in the low-mid 12-volt range, going up to around 14 volts when the car was powered on. This was confirmed by the onboard computer (menu option 9) when I switched it on for a later drive. I observed it during my drive and it held at a pretty steady 14.1-14.2 volts. Turning on headlights and blower would make it momentarily dip into the 13s before coming back to 14v. This, along with the lack of a warning light, all seems to suggest that the alternator is working properly.

The car has been on a battery tender pretty much since Friday when it isn't being driven, and it hasn't gotten to the light pattern that displays 80+% charged. This would seem to suggest that something is either draining the battery while the car is off and protracting the amount of time it takes to reach full charge (which is strange, because no lights are staying on that I can find) or the battery is defective and unable to be charged fully. Charging it out of the car would prove this hypothesis, so I think I might try that next.

Gremlins.

I'm curious what happened. Today, I came out to my car to find no unlock with key, no courtesy lights and nothing when I tried to start it. The battery is 18 months old and it's starting to get warm so it stomped me. I'll see if a friend can jump it in the morning and have Autozone test it. I hope that it's not the alternator but there were no problems on Tuesday when I drove it last. I do remember that the auxiliary fan ran after I shut it down.

Originally Posted by dekaliber

Took it to Autozone earlier today. The guy said that he couldn't test the alternator because the battery isn't in the front

Just put a multi-meter on the front battery terminals under the hood. Are you getting 13.4ish volts?

Originally Posted by smolck

Just put a multi-meter on the front battery terminals under the hood. Are you getting 13.4ish volts?

I'll have to check again, but I did that a couple of weeks ago and believe I was getting mid-12s with the car off and about 14.2-14.3 with the car on.

Car has been fine since then after I let the battery charge back up. Checked the instrument cluster readout (menu option #9) several time since and it's consistently reading around 14.2-14.3 while the car is on, so I have no reason to suspect alternator trouble.