Will the car pop any warning in the cockpit when the battery needs to be replaced? I'm not sure how much juice is left in my battery. Would hate to get stranded cos of a dead battery.

Thanks for any input!

No warning. Better make a proper test, any gas station will do a load test, or read here
http://www.mpoweruk.com/testing.htm

i dont think any computer can warn you of something like that

but its pretty simple to tell, it wont be instant... unless you drain the battery with something

In case your car is an E32, you can unlock the BC and see the battery voltage with ignirion on and the charging voltage while engine runs and while you drive.
It is test # 9
http://home.iae.nl/users/bts/obc.htm

You can do the same on the e38...the instructions on unlocking the OBC are on www.e38.org ...scroll down the page or do a page search [Ctrl+F] and type "secrets" ....the link says something about "OBC secret display".

BTW, its the same TEST #9 on the e38.

PS: hopefully you can see by the multiple answers you received in this post... BECAUSE of your "vague" car info (740i)...people trying to reply to your questions don't know what year your car is. A BMW 740i spans across two generations of cars...the e32 & e38.

Please help us help you better by creating a signature or adding the info to your user profile that gives more specific details about your model & model year. You help us by giving us direction as how to reply to you, and you help others when they are searching the archives...they can compare what model & year you have to their car when trying to find solutions to their problems.

PLEASE...really consider upgrading your sig and car info. :)

If your battery is showing that it's only putting out 11.89volts...it means that battery is at a 0% state of charge (not good) and many times, won't start the car when its that low.

Thanks guys, appreciate the help! Also, updated my car info. :)