How long can a ZHP sit? Or.....how do I track down a drain on the battery?

[redwagon]

I'm more of a mechanical guy......this one has me stumped on where to start.
My ZHP sat undriven for 2.5 weeks in the garage due to biz travel, crap weather, etc. This morning the battery was totally dead. Battery is less than 6 months old......I had bought it when it went dead after the car sat for a week in October.

So either I have really bad luck with batteries.....or I have an ongoing significant drain on the battery even with everything turned off. How does one isolate the drain?

Hopefully the new battery will recover, but I bet its damaged goods at this point.

Tim

[danewilson77]

We have a pretty long parasitic drain thread somewhere. Will find.

HTC Thunderbolt+TT

[danewilson77]

Couldn't find the one I was looking for.

http://forum.e46fanatics.com/showthread.php?t=847871

I swear someone here did a lot of work... Regarding this.

HTC Thunderbolt+TT

[az3579]

I'd still like to answer the first part if the question in the thread title. ZHPs do not like to sit at all. They need to be driven.


Mine will run rough when not driven for a week or two, and will throw a check engine light, which eventually goes away. When I'm away, I have to have someone start it every couple of days otherwise it'll run rough. Always started fine though, so the battery never drained. My battery is only a touch over a year old.


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[redwagon]

I've done some searches and havent found the thread....yet. Most newer cars have a significant parasitic drain, but it should be able to sit a month I'd think.
Tim

[telijah]

To find a drain, I thought one way was to stick a meter on the car, and car pulling fuses one at a time, looking to see a change in the voltage. If the fuses don't shed any light, then relays next...

[aurelius]

Go get a Battery Tender and charge the battery with that, preferably with the negative cable disconnected and the BT plugged into a surge suppressor. It may take quite a while, like 48 hours or more.

If you do this in a garage with trunk lid raised, the lights in the trunk will turn off after a while.

Then if it charges up ok, use the OBC to monitor voltage. If it's low, which it probably will be given how quickly your new batt died, I'd suspect voltage regulator.

Beware situations where you're swapping out batteries and alternators. Start with the VR.

[johnrando]

My parasitic drain was the FSR, final stage resistor. Apparently they are known to go bad and therefore the car doesn't "sleep", and the battery drains. The dealer found this one for me when it was under CPO.

[redwagon]

Thanks all, lets keep the ideas coming.
It charged up fine and started OK today. I think I will need to hook up a meter and watch the drain as I pull fuses.....cant think of any other way to help isolate.

John- re the FSR- if thats a problem doesnt that mean the fan isnt turning off? in my previous E46 I replaced the FSR when I had the mysterious fan speed changes......that was really wierd....wondering if you were experiencing that or if the fan was running low after shutdown.

Tim

[johnrando]

No, it wasn't the fan not turning off. You actually couldn't tell anything was still "on". As described to me, figuratively the BMW sleeps, and the FSR going bad was keeping some systems on, therefore draining the battery.

[telijah]

John, while you're right about the FSR being a common culprit, redwagon is correct in stating that it's fault was shown in the fashion of keeping the air blower running when the car shuts off. Signs of a failing FSR were two main types. A: While the car was running, the air blower speed would randomly either go to full blast, turn completely off, or fluctuate wildly, regardless of the setting you had the fan set to. B: Leaving the air blower on after shutting the car off. The second symptom is what causes many parasitic drains, including myself until about a year ago when I replaced the battery and then the FSR in Sept of last year. It should also be mentioned that it did not always present itself immediately after shutting the car off... for some, they could shut the car off and immediately the blowers would come on, and for others they could shut the car off, walk away, and the FSR would cause the blowers to come on later in time, so yours could have been doing this.

[johnrando]

John, while you're right about the FSR being a common culprit, redwagon is correct in stating that it's fault was shown in the fashion of keeping the air blower running when the car shuts off. Signs of a failing FSR were two main types. A: While the car was running, the air blower speed would randomly either go to full blast, turn completely off, or fluctuate wildly, regardless of the setting you had the fan set to. B: Leaving the air blower on after shutting the car off. The second symptom is what causes many parasitic drains, including myself until about a year ago when I replaced the battery and then the FSR in Sept of last year. It should also be mentioned that it did not always present itself immediately after shutting the car off... for some, they could shut the car off and immediately the blowers would come on, and for others they could shut the car off, walk away, and the FSR would cause the blowers to come on later in time, so yours could have been doing this.

It's possible, but not likely in my case. I'm around my car a lot even when it's not on as I workout in my garage, there is a fridge/tv in there too, plus when I'm doing yard work I have the garage open... I never did hear the fans during that time when it was off with the drain happening (my top is down 90% of the time so I'd probably hear it).

[johnnyrad]

Doesn't Mike Miller stress to have a charger of some sort hooked up to you bimmer if it sits for more then just a few days? If not, then it could suck your battery dry then.

Our cars need lots of attention. :)

[az3579]

Doesn't Mike Miller stress to have a charger of some sort hooked up to you bimmer if it sits for more then just a few days? If not, then it could suck your battery dry then.

Our cars need lots of attention. :)

If this was the case, then my car wouldn't have started after not driving it for the two weeks I went to Florida last year.




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[danewilson77]

If this was the case, then my car wouldn't have started after not driving it for the two weeks I went to Florida last year.




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It is the case.....more often than not. Your car is the exception BP. I am sure it depends on battery state, etc...as well. What Mike says is the most reliable way to ensure your cars health, when leaving idle for a long time.

[Oli77]

This may be the thread Dane was thinking about. http://www.bmwmafia.com/forums/showthread.php?862-Massive-parasitic-current-leak-in-stereo-nav-circuit&highlight=parasitic+drain

You know, the other mafia site.

[danewilson77]

^Yessir...that was it. Thanks

[redwagon]

good thread/reading.........

[LivesNearCostco]

The fan might be hard to hear if it's running on low. I suggest putting the fridge and TV in your ZHP to be closer to the fan. On the other hand with the top down, I guess you would hear the fan if it's running when you're in the garage.

I once let my car sit for a full month (July 2011) and when I came home it started up fine, but the battery was weak, because I then stopped the car, topped off all 4 tires with a compressor using the cigarette lighter, and then it wouldn't start. I took the battery out and found some of the electrolyte cells were a little low so I topped it off with distilled water. It looked like a few of the screw in caps had come loose, letting acid evaporate or splash out. No starting problems since then, but also since then I haven't let the car sit more than 10 days. My battery was installed sometime in in 2009.


It's possible, but not likely in my case. I'm around my car a lot even when it's not on as I workout in my garage, there is a fridge/tv in there too, plus when I'm doing yard work I have the garage open... I never did hear the fans during that time when it was off with the drain happening (my top is down 90% of the time so I'd probably hear it).

[gr330zhp]

I'd still like to answer the first part if the question in the thread title. ZHPs do not like to sit at all. They need to be driven.



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Not necessarily true. If an E46 is parked properly it will run perfectly fine. I store mine every year, put on a maintainer, fuel stabilizer in the tank and clean fluids. The car starts just as well every time. Never thrown a code or any lights on the car.

Though will not argue, they love to be driven, and the harder the better

[johnrando]

The fan might be hard to hear if it's running on low. I suggest putting the fridge and TV in your ZHP to be closer to the fan. On the other hand with the top down, I guess you would hear the fan if it's running when you're in the garage.

I once let my car sit for a full month (July 2011) and when I came home it started up fine, but the battery was weak, because I then stopped the car, topped off all 4 tires with a compressor using the cigarette lighter, and then it wouldn't start. I took the battery out and found some of the electrolyte cells were a little low so I topped it off with distilled water. It looked like a few of the screw in caps had come loose, letting acid evaporate or splash out. No starting problems since then, but also since then I haven't let the car sit more than 10 days. My battery was installed sometime in in 2009.

lol!

[webster]

i suppose this thread is relevant to me currently as with my broken arm and leg, on top of my original vacation...means my car has not been driven in almost a month. i have been having my girlfriend run the car at least once a week, but have been meaning to get her to actually drive it around for a little bit. i'm trying to convince her to let me ride with her. :) we'll see...hopefully this injury stint doesn't cause any issues with the car. especially since it just came back from the shop and was in tip top shape.

[MrMaico]

I've never had any issues with mine sitting for as long as 3 or 4 months in the winter. I just use Sea-Foam for stabilizer and put a trickle charger on it every couple of weeks or so. I do try to drive it once in a while when the roads are dry. This winter though it got driven almost as much as it does in the summer.

[redwagon]

FYI I did some experimentation on my car this weekend with a quality digital multimeter. It seems that after all the lights shut down etc, I have a 42ma load on the battery. Thats pretty low and would take weeks to impact the battery.
Whats interesting though is that I took a number of readings and one time it was about 650ma sitting there and steady even though it had sat for 30+ minutes. Unfortunately by the time I got the glove box open, dropped the fuse tray and waited for the lights to all shut down, somehow that reset things and it went back to the standard 42ma load. So there is something intermittant that comes and gos........sigh........always fun to chase something intermittant.

Tim