If you trickle charge every night with a new battery and you still have the problem, I would be driving a loaner while they figure it out. Have you seen the Discount Tire commercial where the old lady throws her tire through the window? ;)

I put my money on the battery. Replace it and see if that makes a difference. Otherwise something has to be draining it. Simple electronics.

I was told about this Black and Decker (VEC1089ABD - http://www.amazon.com/Black-Decker-V.../dp/B000UZ62FM) recharger on Amazon. It has a feature for reconditioning the battery. Basically it sends low pulse waves for a 24 hour period to break up the crystalization of the fluid, heres from the manual:

Recondition Mode

Whenever a lead-acid battery begins to discharge, lead sulfate, an insulator, begins
to build up on the battery’s internal plates. This reduces the ability of the battery to
hold a full charge. When that battery has an immediate charge, most of the lead
sulfate is dissolved and the plates are free of this insulation. If a battery remains in a
discharged condition over a longer period of time, the lead sulfate changes to a hard
crystalline form, making a full charge difficult to achieve. Reconditioning may “save”
a sulfated battery.
BATTERY RECONDITION MODE should only be used with 10 Amp Hour (Ah) or
larger capacity lead-acid batteries. Charge the battery to be treated for 20 minutes,
before using RECONDITION Mode. Observe the Digital Display for any codes. This
initial charge will check the battery for shorted cells (F01), open cells (F03) or battery
too low to accept a charge (F02), and to ensure the battery can take a charge. If
code (F03) is displayed, change to the BATTERY RECONDITION MODE.

Remove or disconnect the vehicle’s battery when reconditioning.

BTW I just had this issue and simply decided to replace my battery but if this one has any issues I am going to get this thing. Just wanted to share the options I knew of.

Thanks guys,
That's interesting ...
I'm going to ask them to look at the positive and negative cables. Also I want them to check the Intelligent battery sensor and the battery safety terminal.
They replaced the battery last week but I don't want to chance my wife getting stranded. Perhaps they could check the alternator??
They replaced the battery last weekend. Wasn't there something about a factory crimp in some wires or something?

Did you do it with the dealer? How much is it with battery & registration included? Think I saw 1 person mention $500. Or did you skip registration after doing it on your own?

OP.

There is no "one fix" for your reported issue. You can search for weeks here, or listen to a few people replying and you will find that the issue has many potential causes and as a result you are getting varied suggestions for your symptoms.

Without knowing precisely what has been done- diagnostics, no the very short and cryptic data you've supplied- it is impossible to give good guidance.

The root causes can be traced to a few items:
1. BMW uses 'intelligent charging'...decisions about how much power should be drawn from the alternator are done as you drive. Short trips do not allow the system to charge adequately.
2. There are MANY modules that 'hang' on the car's electrical bus which can create current draws. These do NOT turn off when you turn off the key. They can also turn on and off hours after you leave the car- AND can turn on other modules.


BMW has published a work instruction for dealers to completely test for these parasitic drains...it involves hooking the car to a current monitor that logs current draws and times. This does NOT fit into the usual "bring the car in, inspect, diagnose, repair, move to the next car" practice most techs like to follow.

My 2 cents

I did it with the dealer and it was less than 500$. I went around and around for 10 minutes on why not covered but I wasn't winning.
They called me back after my survey and they want to keep it for a couple of days to troubleshoot. He said something is waking up too much.

Yeah. My dealer quoted me $600+ for battery and registration. He was telling me that my 08 used an old/smaller battery and that they need to put in a newer/larger one (thus requiring the registration/reprogramming).

The car has been at the dealer since Friday and it wasn't ready yesterday (Saturday). I followed up and they stated the tech was working on the alarm ...hopefully we'll get some progress this week. Even though it gives me problems I still miss it.