skipper

Thank you everyone for the information. PCY, you were right as well as BimmerFan. I recharged the battery Saturday night and put it in the car on Sunday. I disconnected the IBS wire. Started right up Monday morning. By the way last week when I pulled the battery and charged it overnight and put it in the car it started right up as usual. I brought it to Advanced Auto and they tested the battery and drain and they said everything was good. They couldn't find any issues. But the next morning it was dead as usual. Disconnecting the IBS wire seemed to do the trick.

pcy

Buy new IBS and install. No need to register/code after installing IBS.
There are several threads on IBS installation, please search.

FaintReality

How long should it take for the cars alternator to fully charge a battery while driving? I need to try and figure out why my 07 battery dies every couple weeks or during short periods of radio use and/or opening of the doors which engine off.

skipper

PCY - is it necessary to get a new IBS? I have read threads where people have had it disconnected for years with no issues.

pcy

If the car is not driven more than 20 minutes [on highway] at least few times a week, then it's best to hook up trickle charger and charge it. Recharging the battery will put less stress on the alternator.

pcy

I have also read few members disconnecting IBS and they don't seem to have problems.
I honestly don't know if there are any long term problems as a result of IBS being disconnected. If you have a trickle charger and charge the battery often when the car is not driven long enough, then I think you will be ok. If you go this route, make sure the charger auto-shuts-off after fully charging the battery.

I plan on keeping the car for a long time; so, if I were you, I would replace IBS.

e6t.lab.rat

Over the summer I had BMW perform the recall on the battery cable insulation. Ironically a few months later on occasion my car would struggle to turn over, especially the next morning. I also noticed my radio would just quit while waiting in the car with the engine off. Now this past month my three year old battery finally died. After reading a few post from BimmerFan, I ran some test and determined the car was not properly going to "sleep." So I disconnected the IBS and recharged the battery with a 6 amp Shumaker battery charger overnight (you can charge it with the battery still in car). Guess what? Battery has been good to me since. At this point I'll keep the IBS disconnected until a new battery is required.

plowery21

This post is a great example why 5series is so helpful to all e60 owners. Extremely helpful.

BimmerFan52

If the IBS can't communicate with the ECM then the ECM maps a default charging scenario of a constant 14.3V.

If the battery acid temperature (normally measured by the IBS as one of its functions) is elevated, the ECM might normally choose a lower alternator output voltage to avoid excessive degassing if the IBS were operating, but instead will charge at a straight 14.3V, which could shorten battery life. Conversely, if the car is stopped but idling and the power draw exceeds the alternator output the ECM cannot increase the engine idle speed to help increase alternator output as it would if the IBS were sending information.

Will you see a dramatic shortening of battery life without the IBS? Probably not. Your call.