Hi all,

How does one know when the battery is to be replaced? I have a 2009 R56S, 90K kms on it. Battery is original (Varta). I've been having some electrical gremlins in the car on and off - at one point, only the left side lights turned on (and wouldn't turn off, had to stop the car and turn it off), I had some odd scan errors with the BT tool (i.e. 5E31:Control unit internal: System voltage low), etc. Yet, when I look at the Varta battery's little indicator window, it shows Green, so it's not due to be replaced per the battery itself. Do I trust it, or do I buy another one? Is 7 years too long?

Thanks.

 

Yup, replace it. 7 years is way past end of life..

 

Batteries are rated for 3-5 years, so if you've exceeded that you would be doing yourself a favor to replace it before it leaves you stranded. You can have the battery tested, but these cars are so electrically dependent that a dying battery will cause all sorts of weird problems, and the oh so loved no start..

 

If you're curious, use a multimeter to check DC voltage across the battery terminals when the car is not running. Anything much under 12.5 volts isn't good. Anything under 12V and the car may not start.

 

I just replaced mine. The battery was 5 years old. The other members are spot on when they mentioned about the 'issues' that pop-up with a weak or dying battery. Mine had electrical gremlins from lights, windows, slow cranking and most of the times, will not crank at all! Replace it and not worry.

 

Never had a cranking problem, but the gremlins were occasional, and odd, and made me wonder about that other known problem - water leaking into the footwell module and causing rust in it. The problem is, since the occurrences were so odd and random, I can't even realistically compare them to a new battery - but anyway, I just replaced it for peace of mind. The group 48 H6 type from Costco was slightly larger than the OEM one, but fit perfectly into the opening. No IBS, so I didn't do any sort of recalibration. Car runs fine FWIW. So now I look for the absence of gremlins, which is about as easy to do as proving one doesn't have a sister :D