I just bought a 2003 530i and the battery looks old. I'd like to get a new battery but would prefer a sealed or gel battery like an Optima or Braille, both of which are lighter and more powerful than the replacement battery from Interstate. Has anyone put an Optima, Braille or other brand of gel cell in their car?
I have an Optima in my older I have an Optima in my older 3.0cs, and it works fine. Also have an Interstate in my e39 touring. But if I had to do it again, I would put an Odyssey battery in both, due to the small size and weight savings. http://www.odysseyfactory.com
You could try a charger... I just ended up buying a nice "smart" charger and hook up my baby every time I put her to bed...it's been over two years and the battery is still working/charging perfectly. Just remember that the system continues to drain the battery for 15-minutes after you shut her down because of diagnostics. You should notice that little orange light around your shifter, which illuminates for 15-minutes after you've turned off your ignition or open your hood, trunk or doors. If you don't drive an hour to work on the freeway everyday, most likely the problem is that the battery doesn't get enough charge time before being drained again...just FYI. Look at the Bentley brick (if you have one) and it shows the proper charge state for our batteries...
Other Than OEM I replaced my BMW Battery with a 49H8 Gold series battery from Advance Auto Parts. Perfect fit for my 540i - no need to change the vent hose because it fits into the battery just like an OEM battery. It has a higher CCA than required as well as Ah. I also got it far cheaper than a battery from BMW. I paid $110 (after redeeming the core charge of $12). All is well.
