Battery low warning

I just got back from a four day car camping trip. From about two days, my car was parked and basically never opened except for unloading. Because of racoons and such, I kept my dry food stored in a bin in the back and I'd do a lot of opening and closing of the car at dinner and breakfast time.

When I started the car to leave, the clock was blinking and I had a warning message about low battery.

Is this normal behavior? There was certainly some discharge of the battery over those three days (although not extreme, by any means. Should I be concerned?

Originally Posted by Kilgore Trout

I just got back from a four day car camping trip. From about two days, my car was parked and basically never opened except for unloading. Because of racoons and such, I kept my dry food stored in a bin in the back and I'd do a lot of opening and closing of the car at dinner and breakfast time.

When I started the car to leave, the clock was blinking and I had a warning message about low battery.

Is this normal behavior? There was certainly some discharge of the battery over those three days (although not extreme, by any means. Should I be concerned?

Sounds like your battery is starting to go. I've left my car parked for months without starting and didn't have a problem. How old is the battery?

Originally Posted by Kilgore Trout

I just got back from a four day car camping trip. From about two days, my car was parked and basically never opened except for unloading. Because of racoons and such, I kept my dry food stored in a bin in the back and I'd do a lot of opening and closing of the car at dinner and breakfast time.

When I started the car to leave, the clock was blinking and I had a warning message about low battery.

Is this normal behavior? There was certainly some discharge of the battery over those three days (although not extreme, by any means. Should I be concerned?

Sounds like a little driving will get your battery charged up. We had a thread not too long ago about battery life and reports were quite diverse (3 - 5 yrs generally). The most interesting note that came out of this was a warning from BMW (some owner's manuals) about daily driving habits and keeping the battery charged:

"if your car is driven only for short distances of less than 10 miles over a prolonged period of time, without an occasional drive at highway speeds, the engines (sic) charging system will not maintain the battery."

Somewhat of a challenge for "seniors" who may only go to Costco once per week!

how many times did you unlock the doors? it takes 30-60 minutes for all the car electronics to go to sleep where the drain is 40mA. until then, there is a pretty big drain on the battery, depending on options, while the electronics are awake.

Kilgore, have the electrical system checked out - especially the IBS (intelligent battery sensor). I had the battery low warning on my CPO '07 E91 (original battery, ca. 37,000 miles), followed by the car stalling going around a slow corner.

Dealer found nothing wrong until they tried to move the car at which point it wouldn't start. When it did start, the alternator was charging at 17+ volts. Alternator was replaced. Dealer said that sometimes happens on the 7 series but is uncommon for an E9x.

A few weeks later, the Low Battery warning came up again - new alternator found to be overcharging at 15+ volts, replaced again.

Two weeks later, with the car in for unrelated service (and no more dash warnings), I luckily asked them to check the charging system. Sure enough, the alternator was again overcharging and this time they checked the IBS unit which was found to have an intermittent fault (first time my dealership had encountered this problem - ain't it fun being a guinea pig?).

Battery cable and offending IBS unit replaced and all has been fine for the past 4,000 miles. Glad the car was under warranty as alternators are something like $900 a shot!

Let us know what happens with your wagon.

Tom

My car is only 2 1/2 years old. And, I put about 15,000 miles a year on it. So, it is not a situation where it is not driven regularly.

Based on what you are all saying, I think I may need to have it checked by the dealer.

Originally Posted by Orient330iNYC

how many times did you unlock the doors? it takes 30-60 minutes for all the car electronics to go to sleep where the drain is 40mA. until then, there is a pretty big drain on the battery, depending on options, while the electronics are awake.

I'm just experiencing this: lights that stay on for an unnecessary amount of time; example, the parking indicator light stays on for nearly 1/2 hr after exiting the car. Certainly this is not drawing much, but what else is staying on, why so long?

Originally Posted by Orient330iNYC

how many times did you unlock the doors? it takes 30-60 minutes for all the car electronics to go to sleep where the drain is 40mA. until then, there is a pretty big drain on the battery, depending on options, while the electronics are awake.

I didn't unlock and lock the doors a lot. But, I was opening and shutting the hatch quite a bit. I do have iDrive, btw, so there is a spinning hard drive in the dash.

When I started getting that warning, it was the beginning of the end of my battery. Mine was probably 3.5 years old. Mine was replaced under warranty, but that's a debate I hope I don't reopen.

Originally Posted by Kilgore Trout

I didn't unlock and lock the doors a lot. But, I was opening and shutting the hatch quite a bit. I do have iDrive, btw, so there is a spinning hard drive in the dash.

its not just that spinning up-- all the other systems of the car wake up/stay awake.

i'm trying to find the documentation, but IIRC, the drain is pretty significant with all systems awake.

Originally Posted by Orient330iNYC

its not just that spinning up-- all the other systems of the car wake up/stay awake.

i'm trying to find the documentation, but IIRC, the drain is pretty significant with all systems awake.

Does opening the wagon hatch really wake up all the systems in the car?

Originally Posted by Bill-SD

When I started getting that warning, it was the beginning of the end of my battery. Mine was probably 3.5 years old. Mine was replaced under warranty, but that's a debate I hope I don't reopen.

Well, that closes the deal for me. Off to the dealer with the car, and we'll see what he has to say.

Originally Posted by Kilgore Trout

Well, that closes the deal for me. Off to the dealer with the car, and we'll see what he has to say.

Definately have it checked. I think mine must have been slowly dying for a while. My CA got to the point where it only worked about half the time. After the new battery it works 99.9% of the time.

Originally Posted by Bill-SD

Definately have it checked. I think mine must have been slowly dying for a while. My CA got to the point where it only worked about half the time. After the new battery it works 99.9% of the time.

Thanks, Bill. And, also thanks to Tom, Orient330iNYC, Sunny5280. You guys are fantastic resource!

Originally Posted by Kilgore Trout

Thanks, Bill. And, also thanks to Tom, Orient330iNYC, Sunny5280. You guys are fantastic resource!

So I'm chopped liver? You've drained your battery according to the meister (Orient)...my guess at first.

Interested to hear how the conversation w/ your dealer goes. Got my low battery symbol at about the same time as you KT, & it's been a street fight with my dealer ever since.

"Are you driving enough?", "You need a trickle charger", "You aren't shutting down properly"...

I've just started a thread about a battery recall. My e91 is exactly 2 years old and there is a recall for battery replacement. I don't know a reason an if it is co-related to your ride but you could check it out with your dealer.

Originally Posted by pointandgo

So I'm chopped liver? You've drained your battery according to the meister (Orient)...my guess at first.

sorry P&G, didn't mean to blow off your accomplishments. Was just to lazy to check on everybody who had been posting in this thread.

I have noticed that I can not allow the car to sit for more than 2 weeks with out being on a tender. I found that out when the car was months old, and sat unattended for 2 weeks. If the car is going to be sitting for more than a week, I plug it in. I have not experianced any other problems with the battery. I also drive less than the OP.

Originally Posted by mwpepper

I have noticed that I can not allow the car to sit for more than 2 weeks with out being on a tender. I found that out when the car was months old, and sat unattended for 2 weeks. If the car is going to be sitting for more than a week, I plug it in. I have not experianced any other problems with the battery. I also drive less than the OP.

I had it left for 6 weeks once. No problem.

Originally Posted by mwpepper

I have noticed that I can not allow the car to sit for more than 2 weeks with out being on a tender. I found that out when the car was months old, and sat unattended for 2 weeks. If the car is going to be sitting for more than a week, I plug it in. I have not experianced any other problems with the battery. I also drive less than the OP.

I've left my car parked for months at a time without problem. If you can't leave yours parked for two weeks then your battery is on the way out or something else is wrong.

Originally Posted by pointandgo

So I'm chopped liver? You've drained your battery according to the meister (Orient)...my guess at first.

Dealer called. You and Orient were correct. There is a fault code showing that a door left open drained the battery.

We'll see if it happens again.

They did correct one or two other problems while it was in the shop, so its all good in the end.

Originally Posted by Orient330iNYC

how many times did you unlock the doors? it takes 30-60 minutes for all the car electronics to go to sleep where the drain is 40mA. until then, there is a pretty big drain on the battery, depending on options, while the electronics are awake.

If you just close the door the car will stay awake for that time, but I believe you can speed up the process by locking the door.

Originally Posted by pointandgo

I'm just experiencing this: lights that stay on for an unnecessary amount of time; example, the parking indicator light stays on for nearly 1/2 hr after exiting the car. Certainly this is not drawing much, but what else is staying on, why so long?

From a cold start, there are a lot of components that need to "spool up" so to speak. The car is designed to keep a lot of the electronics active to minimize this spool up time when you are making short/quick trips. If you have the second gen iDrive you can really notice that it takes a good 30-45 seconds to display the intial map screen when you cold start but only about 15 seconds from a warm start when the car is awake. Same is true for the fuel pump, etc. The engineers designed it so as long as you stop and start the car within 16 minutes (I believe that is the snooze time), everything stays awake. Between 16-30 minutes more stuff goes to sleep and after an hour everything goes to sleep.

Originally Posted by Kilgore Trout

Dealer called. You and Orient were correct. There is a fault code showing that a door left open drained the battery.

We'll see if it happens again.

They did correct one or two other problems while it was in the shop, so its all good in the end.

Glad it turned out to be something simple!