audiophool

For the last year or so, if I don't charge the battery every week, the clock and trip odo reset and I get an 'increased battery drain' message on iDrive. So far the car has always cranked/started fine.

Yesterday I made a bunch of really short trips and got a car wash**, parked on the drive and when I went out a bit later it would not crank at all. Put the battery charger on and it started OK a bit later.

Now, when I first open the driver's door, I see a bright flash on the instrument panel between the tach and speedo (too quick to see what it says) and the interior lights don't come on. If I close and re-open the door I don't see the flash and the interior lights come on as normal. Comfort access doesn't seem to be working either (remote works).

I've not driven the car since charging aside from parking it in the garage.

So, likely the original battery (eye is black and has been since I bought the car in 2012) and time for a new one. Any thoughts about the weirdness of the flashing instrument cluster??


** During the car wash (wand), the car always locks and unlocks whenever water is sprayed around any of the door handles. The car was really dirty so it probably cycled a dozen times. Stupid design.

BimmerFan52

I don't know when you had to begin charging it every week, and how bad the battery was when you began this practice.

Given your comments about the car locking and unlocking during washing, I would suspect you are experiencing the rather common comfort access door handle problem that causes the car to repeatedly wake up on late model E60s, running down the battery.

If the battery stays in a low charge state for an extended period of time sulfur crystals will form on the charging plates, blocking future charging of the battery. Eventually they harden to the point that charging is no longer successful and the battery must be replaced.

So you have two objectives.

First find out if your car is repeatedly waking at night, causing the ECM (DME) to wake up and dramatically increase the at rest power usage. If you have an automatic you will see an LED light next to the gear shift. Once that light goes out the car has gone to sleep. Keep an eye on it through the window (opening the door will also wake the car up). Also, some users find they have to lock the car in the garage and then keep the key fob far away from the car to have it remain asleep.

Second, you need to determine if the battery has been damaged to the point that it is no longer viable. While regular weekly charging of a battery in excellent health (topping off the charge to prevent sulfation of the charging plates) is a very good practice to keep it healthy, I don't think you want to risk being stranded if the battery is already at the end of its life and you can't charge it that week. An auto parts store or battery store can test the battery to ensure it is still good. As a side note, the alternator will also obviously come in to play and an auto store can also test the alternator output to determine that it is providing enough current to the system load to bring the system voltage to an acceptable level.

audiophool

I had the stealer check the charging system last year and they said it was OK and that the battery needed to be charged once a week to prevent issues. Alternator is working properly - I get a stable 14.4V at idle.

Until yesterday the battery has never discharged to the point of not cranking the car. I've checked that the car does go to sleep ("P" LED on the shifter does go out and stay out). And after a few more lock/unlock cycles the comfort access is working.

Probably just time for a new battery.

twh

Being told to charge the battery once a week is nuts. It is true that the dealer can look at the car codes and get the "unfavorable driving profile". I had this on my car, but my BMW dealer didn't bother to tell me cause they knew I'd say so I don't care. My 2006 530 doesn't get driven much. I have 60,000 miles. I drive a few times a week. Never ever charge the battery. On my third battery.

audiophool

Well, I thought being told to charge weekly was nuts as well, but without doing it the dread iDrive message would ensue.

That said, I drive the car at least 6 days a week and it's rare to have a trip less than a half hour which should be more than enough for a 180 amp alternator to replenish.

BimmerFan52

Yes, it sounds like you are doing plenty of driving to keep the battery charged.

I would replace the battery and not use your battery charger for the first few weeks. Then daily measure and document the new battery's voltage (measure the battery voltage after it has sat overnight before starting the car). You will quickly know if unbeknownst to you the car is waking up and running down the battery.

twh

What size battery is in the car? Maybe the one installed now is undersized.

audiophool

It's the OE battery - the size of a bread box. After 6+ years, time for a new one. Interstate has 3 options, one being AGM. But in my climate, the AGM isn't recommended, rather the Megatron Plus.

cakes

If your current battery is an AGM, you should stick to AGM, and if it's FLA, go with FLA. Either way you'll need to have an indy "register" the battery with the ECU

metalicnight

+1 on Cakes reply. In your part of the woods Interstate is the brand!