Terenc3

I drive a 2006 Chevy cobalt 2.4L. And I’ve been plagued with a problem for the passed few winters



Ok so my car is killing my battery after a day or so of sitting. In the summer my car can last a few days but now that it’s colder it doesn’t last the night



My alternator, starter and battery are all new within the passed year.



I did a drain test and my car pulls .18amps until the entire thing goes to sleep a half hour later where there is no visible drain.



Even though there is no visible drain my battery was at 12.6v last night and this morning it has dropped to 12.16v.



When the car is running my alternator reads over 14v, so I would say my cars electrical is healthy.



I cleaned and tightened all connectors to the battery. After everything my car is still dying overnight.

Does anybody have any ideas?

ProfDNS

Do you have any extra accessories, or even an aftermarket radio installed?

Terenc3

I do have an aftermarket stereo, but with no parasitic drain detected, I figured there wasn’t an issue. Could the stereo be draining the battery even though I only read .01amps draw on my multimeter?

ProfDNS

Honestly yes. If you have the radio (or other aftermarket stuff, like amps, LEDs etc) that's wired to 12V constant on, it will kill the battery overnight. Even the 12V direct from the cigarette lighter outlets will drain. Case and point, I drive my car maybe once a week, usually on a weekend. On a Saturday, I did my thing, parked and left it for 3 days before I had to go to the store. Battery was dead. I left my dash cam system plugged into the 12V direct. Normally the car can sit for a couple of weeks before that happens.

ECaulk

iTrader: (6)

Just because the battery is less than a year old does not mean it isn't bad.

Get the battery tested to verify everything is ok.

Seeing 12v after sitting is in the normal range, if it's below 11v that's when you need to start being concerned.

Terenc3

all my stuff is wired to a switched fuse. I don’t have anything on constant 12v.

let’s say the radio is the culprit, if I was to pull the radio fuse would that stop it from drawing? Just test for a night ?

Tdubbs

Realistically the rule of thumb is you shouldn't have more that 30-40ma (.03-.04a) draw after everything shuts down. I'd get a reading after it's all "asleep", then same thing but radio fuse pulled out and note the difference.

Terenc3

i already did that when I did my drain test.
it was unchanged.

after my car goes to sleep the draw is only .01 but for some reason my battery still dies

USMCFieldMP

iTrader: (1)

I'm assuming you checked both fuse boxes? Who installed the stereo? Are you sure they didn't pull power from some other circuit or constant power source? Any additional connections on the battery?

Terenc3

Like I said, my draw is only at .01
i pulled every fuse in the fuse box to check for drain and I didn’t find anything
The stereo was professionally installed. I looked at the wiring and everything seems normal. I’m going to pull the fuse for the stereo and let it sit over night to see if that changes anything. I do know that the stereo does require a certain amount of power when the car is off to save clock setting etc, so I’m thinking maybe that could be causing the drain.
I guess I’ll find out

ProfDNS

If pulling the fuse fixes it, the 12V (red wire usually) is not in 12V aux, but 12V always on.
ECaulk is correct though too: If you have an acid battery, multiple deep drains will kill the battery. Could very well be Occam's Razor at this point.

Terenc3

So I pulled the fuse from the stereo over night and to no avail. The voltage of the battery dropped from 12.6 to 12.08 overnight. My car still started but the drain is still there. I have no idea what it could possibly be now.

ProfDNS

Honestly at this point, you might have to test each and every fuse point (starting inside the engine) and see if you can't gather some info there.

Terenc3

that was one of the first things I did. I didn’t find anything

Terenc3

so I took my battery off the car and left it over night to see if there was a drop in voltage. It went from 12.7 down to 12.45 which doesn’t seem significant. So I guess I can’t rule out a bad battery. I’m completely stumped. My multimeter shows no parasitic drain when connected but my battery keeps dying. Don’t know what to do

ProfDNS

Do you do the fuses under the hood, and inside the car? I think there's another set of fuses where the driver side door meets the dash but I don't remember if there is anything significant there. In addition, if there are any blown fuses, those would be noteworthy as well.

USMCFieldMP

iTrader: (1)

So the battery removed and not connected to anything caused it to lose half of the voltage that it lost when connected to the car. Sounds like that might be your issue.

You said it's newer, so it should still be under warranty. Just have it replaced.

Terenc3

I just figured the voltage drop was because I just pulled it off the charger. This will be my third battery that has gone bad, that’s why I don’t think it’s the battery.

ProfDNS

It wouldn't be a bad idea to get a health check on the battery just to rule it out as you're doing your process of elimination. Auto parts stores usually test them for free.

Terenc3

just got my battery tested today, they said it was fine. I really have no idea what to do now.
I was thinking of putting a second battery in to see if that helps, but who knows it might just kill both of them

chevy2

My SS/TC has the same problem. The stock stereo head unit would drain the battery overnight, or maybe it was the remote keyless entry function that was awake all night and drained the battery. In any event, I gave up trying to defeat all that stuff.
So, my "dumb" solution to the problem was/is:
For instance, I travel occasionally and the car's away from home for 1 or more nights, so I installed a 12v battery kill switch in the trunk.
I added ~ 5' of battery cable and a couple connectors from the battery to the kill switch and out.
When I'm done driving for the day, I pop the trunk lid and throw the switch and put the "key" to the switch in my pocket.
The downside is, the starter engages for a longer period of time when starting the car when next I get in to take off,
and of course, all my settings have been erased, but to me, it beats the alternative.

On another car, the factory clock and/or aftermarket stereo would drain the battery over two days of not driving it,
so I disconnected the clock forever and I installed a simple kill switch that I can reach from the driver's seat, between the fuse box and the hot wire to the stereo. Voila. Problem solved for both cars.

When the SS is at home, I hook up a trickle charger at night and ignore the battery kill switch in the trunk.
You can connect the trickle charger with an additional connector that stays hooked to the battery,
so you plug in the charger as you would plugging in an engine heater every night.

Good luck with this.