View Full Version : Battey Keeps Dying

02-13-2009, 11:34 AM
AZ was down so I posted this on Fourtitude but got no answer...

So a month ago I drove about 20 minutes, turned the car off for 5 minutes to pick someone up and left the headlights, AC, seat heaters and radio on, the car then wouldn't start. I figured they just drained the battery. I waited 10 minutes with everything off and the car started.

Two weeks ago I went to go snowboarding. The night before I started the car and ran it for 10 minutes to make sure it would start the next day. It didn't, ****ed up my snowboarding trip and cost 65 dollar to jump.

This was annoying but I kind of chalked it up to the frigid temperatures and the fact that I drive my car like once a month. There were two other occasions in the past month where the car started fine in the cold after not being touched for a while though.

Yesterday I go to start the car and it wouldn't start, and it was warm out. I jumped it and finally brought it to Sears to have it tested (the current battery is from Sears so I was hoping for some warranty action). They tested the battery and these are the results:

CCA = 540
Cranking Volts = 10.66
Load Volts = 13.77
No-Load Volts = 13.77

They told me the battery is fine; just start the car every other day. This was yesterday at 4 PM. I go to start the car just now and it won't turn over. A little over a day after and its 50 degrees out.

What the hell is wrong with the car? After I get it started the voltage gauge flies up so I take that to mean the alternator works. Is it possible that something is on in the car that's draining the battery? I haven't done any modifications to the car in quite some time, this just happened all on its own. I'm going to wake up at 7AM to go snowboarding; I'll need to find someone to jump my car. Good thing I bought cables at Sears yesterday. Who the hell is going to be up at 7AM on a Friday though.


I went to start the car this morning and it wouldn't start, it lost all of its charge in 6 hours. [=(]

02-13-2009, 11:37 AM
Use a test light to see if you have a draw and then start pulling fuses until the light goes off.

02-13-2009, 11:55 AM
Try these links.

I had the same thing happening and this turned out to be the solution..a broken Load Reduction relay

If not, try this to test for a parasitic drain..

Edit: What year is your car?

02-13-2009, 12:36 PM
98.5, the first link doesn't seem to be the same problem but the second one look like it's what I'll need to do. I don't want to disconnect the battery though because i don't have my radio code. :( My friend just jumped the car with his MINI Cooper and I'm just going to let it run until I go home in a few hours, I hope it doesn't run out of gas the light is on :p

02-13-2009, 01:00 PM
Getting the radio code is pretty crucial to the whole operation id say. Good luck getting home though. How long are you planning to let the car idle with the gas light on?

02-13-2009, 01:20 PM
dorms close at 6 so under two more hours. i could probably turn it off now and it'll be good for 2 hours but everyone i know with a car is gone already

02-13-2009, 01:27 PM
Suck you have to wait that long. Idling the car for 2 hours will probably use just under a gallon of gas fyi. (I left my car running for 4 hrs and used 2 gallons one time)

02-13-2009, 10:07 PM
It's most likely the alternator or even possibly the coolant temp sensor ($20) or icv. Ive been dealing with similar problems. Check the resistance on the Icv it should be around 11ohms.

02-18-2009, 06:19 AM
So...I got around to the test today to see what's draining the battery with the car off.

To start, the car wouldn't start again (though it started the other day). So I jumped figuring I'd have a charged battery for the test. I turned the car off and left it in the accessory position and could see the voltage meter go down. I went to start the car 20 seconds later and it wouldn't. So I carried on with the test. With the car completely off. This is how I setup the test:

After pulling the fuses one by one I came to the conclusion that the two main drains are numbers 15 and 28:

After the test I put the key in the ignition and pushed it forward one notch and just watched the battery meter go down. I took the key out and checked the voltage, I could watch the voltage go back up very slowly:

Back to the fuses, #15, when pulled and put back in would draw ~110milliamps, but after about a minute it would drop to almost nothing. #28 pulled ~40milliamps. So with all the fuses in, the car pulled ~43milliamps, which I take to be normal. According to an AudiWorld article, #15 is "Instrument cluster, power windows, climate control, automatic transmission" and #28 is "Fuel pump." Now I have no idea why the fuel pump is draining power with the car off, but isn't the car at an acceptable draw rate?

Combined with the beginning of the post and these findings I've come to the conclusion that when the car is in accessory mode something is draining the battery fast but I can't really find a substantial unusual draw with the car off. I feel like that doesn't make a whole lot of sense because when I start the car I just start it, I don't even sit in accessory mode for a second. Anyway, I went to check the amperage draw with the car in accessory mode and I'm pretty sure I broke the amperage component of the multimeter (sorry dad) because it's sitting at 0 no matter what.

What to do. Anyone?

02-18-2009, 09:29 AM
Interesting findings you've got there. I dont know if I can help your too much but I can tell you I went through the same process with my car 2 weeks ago. Turned out to be the Load Reduction Relay stuck on drawing 28 milliamps when the car is off.

- I found out the car should draw < 4 milliamps when off.
- when testing, whatever door is open, you need to close the latching mechanism on the edge of the door. otherwise it will draw current from the battery.

ill ask my mechanic and send him this page to see if he has any ideas since he diagnosed my draw

02-18-2009, 04:09 PM
I was running on the assumption that 25-50 milliamps is normal from this:

Are you sure 4 is average? I think when I pulled #28, the fuel pump and #15 had been idle for a minute my draw was 6.5 which would be close enough to your normal.

02-18-2009, 05:12 PM
On my multimeter it reads milliamps in decimals (ex: .04 = 4 milliamps)

I was told by my mechanic that under 4 milliamps is what the draw should be when the car is completely off. Of course the lower the better. Also when I found the culprit to my power drain issue, the multimeter dropped from .28 to .4 milliamps of draw.

That article is just saying that when your pulling 25-50 milliamps (.25 -.5)when the car is in sleep mode, then you have a parasitic drain.

Just to give you an idea, turning on the one light in the trunk made the battery draw go from 4 to 80ish milliamps (.04 to .8).

Based on what you found with the fuses, i would say check your fuel pump relay as welll as other relays. One could have melted/malfunctioned causing the circuit to stay closed and drain the battery.

02-18-2009, 05:43 PM
Well I'm pretty sure I ruined the ammeter component of the multimeter so I can't really do any more tests like. I think for now I'm going to go jump it and drive around for a while, then park it overnight with the fuel pump fuse pulled and see if it starts tomorrow. It's annoying because this is somewhat inconsistent, it started fine the other day after not being used for ~24 hours and it was freezing out.

(When I was doing this this morning it was ~20 degrees out and the car was covered in ice, after jumping it I could watch the mirrors steam and melt the ice off, I always assumed the heated mirrors didn't work :p)

02-18-2009, 06:06 PM
either replace the battery, or actually charge it, I had the same problem for awhile, but then I just charged my battery with an actual charger, you can buy a cheap one from advanced or anywhere for like 10 dollars and it does the job, your thinking to deeply into it I think, I could be wrong though

02-18-2009, 08:09 PM
I have a charger I can use, I guess I can try that at another time but I'm still fiddling with the fuses.

I just jumped the car and went for a two hour drive. When I got home I turned the car off and pulled the #28 fuse and noticed that the lights turned off immediately. I closed and locked the doors and I didn't hear the other doors lock, I unlocked the door and it wouldn't unlock totally. I went back into my Chilton's book and it seems i misread earlier. It's the #38 not the #28 fuse that's pulling power. #38 is "Luggage compartment light, central locking system"
That would explain the door not locking right and the lights shutting off. I just hope I can unlock the door tomorrow with the central locking system disconnected. The back seat is folded down so hopefully I can at least crawl through the trunk.

Anyway, I guess I can focus on the "Luggage compartment light, central locking system" instead of the Fuel Pump like I thought. As far as I can tell there are no lights on inside the car, my back seat has been folded down for a while and no light has been on in there. I don't think the glove compartment light is on. Is there a way I can test to see if the central locking system is draining power? The wiring diagram looks pretty damn complicated.

02-18-2009, 09:16 PM
If you are losing 110mA and you say the car sat for 6 hours you are only losing about .66Ah of capacity. A single AA battery has a capacity of about 1.5ah. Though, a car battery is not designed for capacity, but for high discharge rates, I can assure you there is plenty more capacity to maintain a proper discharge rate and voltage to crank over a car.

The doors locking slowly is because the vacuum pump in the rear is possibly on its way out. They don't operate electrically directly, unless your power is so low you can't get a good vacuum.

I honestly think you just need to shell out for a new battery. I my car sat for 2 weeks when I was on vacation and started right up. I've played my stereo system for 1.5 hours and the car still started up. Judging by the pics, the battery looks rather old so it might just be tired.

Try driving around to let the alternator charge the battery. then park it, and unplug the negative strap. wait a couple hours, then reconnect and try to start. the battery itself has internal resistance and will leak voltage on its own. if it fails to start, you just need a new battery and the mystery is solved.

02-18-2009, 09:42 PM
The pump didn't operate at all...the fuse was pulled.

I guess after my little test tonight I can try your test, I was running on the assumption that the battery itself was OK since I had it tested and they said it was fine. I bought it in July of 06...so it's 2.5 years old.

02-18-2009, 09:46 PM
The pump didn't operate at all...the fuse was pulled.

I guess after my little test tonight I can try your test, I was running on the assumption that the battery itself was OK since I had it tested and they said it was fine. I bought it in July of 06...so it's 2.5 years old.

The battery is kinda new, but batteries shit the bed all the time. I carry two fully charged spares on my boat all the time.

02-18-2009, 09:55 PM
So should I just disregard the test? They assured me that I don't need a new battery, it's fine, just start my car more often.

02-18-2009, 10:38 PM
if you need to start you car more often, the something is not fine. haha.

110ma is tolerable parasitic loss. most batteries are atleast 30ah capacity if not more. It would take about 90-100 hours to drain it down to 20ah

02-18-2009, 10:39 PM
also, don't forget when you open the drivers door, the clock and odemeter automatically light up till you close the door for a couple minutes.

02-18-2009, 11:28 PM
Right, that would explain #15 would be at 110 then drop 2 minutes later. I guess I'll just go with your suggestion of disconnecting the battery for a while and seeing if it starts a few hours later to completely eliminate parasitic loss. If it doesn't start I'll buy a new battery. Any suggestions on brands?

02-18-2009, 11:32 PM
I usually go the cheapest way possible. haha so i'm no help

02-19-2009, 12:23 AM
I'm not really sure what battery is better than another or if any of it makes much of a difference. When I first went to Sears I was hoping they'd replace the battery because they have a three year warranty. That's why they ran the test. It passed the test so they won't replace it. (By replacement I mean pro-rate it which probably means a 6 dollar discount)

02-19-2009, 04:37 AM
I bring you new evidence, and you had me a convinced!

So after last nights two hour drive I pulled the #38 fuse and left it over night. 8 Hours later (10 minutes ago) I go to start the car with the fuse still out, starts fine:

I drive probably two miles, park the car, go inside to get the fuse, pop the fuse in, wait 10 seconds, this is what happens:

Still think it's the battery?

I pulled the fuse again and I'm going to try to start it again in another 10 minutes, but now I'm convinced it's that circuit.

02-19-2009, 02:27 PM
hhmm wierd. next time leave the car with the fuse out. then go back 8 hours and put the fuse in a start it. shut it off....then restart to. maybe you are discharging the battery below usable level on the first charge

02-19-2009, 02:38 PM
You going crazy wasiting time. Just go get a new battery and start fresh. And batteries can actually discharge by themselves. And I wouldn't trust a sears battery as far as I can throw it!!

02-23-2009, 04:40 AM
i ended up going back to sears again. i parked it and when i went to move it into the garage it needed to be jumped, then to start the car and test the battery it needed to be jumped. it was pretty clear it was bad and it was still under warranty. completely free battery and service. yay!

03-08-2009, 09:16 PM
Im having the same problem. Brand new battery gets drained in a few hours by god knows what.

03-09-2009, 10:15 AM
make sure to put some terminal cleaner spray or petrolium jelly (KY works fine i believe) on the terminals to avoid growing a chia pet on your new battery terminals. i've always heard throughout all of my personal training that < .050a (50 mA) is acceptable drain for a vehicle with the key off and removed (vehicle in sleep mode). i think you probably just had a dead cell and the normal draw of the vehicle was killing it. you shouldnt have any problems out of the new battery.

fyi interstate provides the oem batteries at my dealer so i would suggest interstate for anyone else who might need a battery.

03-11-2009, 02:26 PM
i had the same problem three weeks ago.
ends up the alternateur had a bad wiring connection.

03-11-2009, 05:26 PM
Ends up mine was a loose ground on my A/f gauge :/
at least it was an easy fix.