Battery Replacement...when?

[johntomferg]

I'm wondering what kind of interval other people are seeing with their battery. I picked the car up in October 2012 and have never had a need to replace the battery now with >75k miles on the car. I understand that the AGM batteries *can* last a long time, but just checking in to see whether this is typical.

Comments welcome.

[JMD]

I would never worry about replacing the battery until the car begins to have "starting" problem! For instant,...if you every need a "jump start",....then the battery is near dead,...or the alternator is not charging! For the most part,...I'd put the blame on the battery first!

For the record,...every battery ever made is going to "die",...sooner or later! No matter the technology!

GL

[johntomferg]

thanks for the reply. I'm not losing sleep over it, just curious. :-)

[ur20v]

Car will tell you... it monitors battery condition, charge and discharge rates very closely and will put a warning up to replace the battery when required

[Official NOCO]

If all the electronics are working, and the car is starting fine then you're battery is fine. It is no surprise it has lasted this long.

Car batteries tend to do better when they are used daily, as the alternator charges the battery every time you drive. This is why cars that are garaged are typically supposed to be hooked up to trickle chargers.

[Maverick997]

They changed mine at my 20k miles service......wasn't giving any issues but they changed it....

[ur20v]

^^^ will have thrown a code.

[phil_]

I had my battery go bad on my E60 M5 and F10 M5.

You'll start getting messages that electronics were shut off. You might even lose the clock settings. If the battery is really low comfort access will be shut off and won't work.

Another effect and the reason I replaced them was because the fan would only work at low speeds. There's some sort of protection to prevent the fan from working full speed when the battery is low. It's actually a safety issue when you can't defrost your windshield.

My E60 M5 was out of warranty and I paid out of pocket. For the F10 M5 they ran some tests on it. Determined it was out of spec and was replaced with warranty. Car had 3 years / 45,000 miles at the time.