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      12-21-2012, 12:51 AM   #18
Second Lieutenant
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Drives: 2015 GTR
Join Date: Oct 2012
Location: Nashville, TN

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Originally Posted by MRV99 View Post
BMW's qualifies a bad profile by somebody who drive less than 5km at a time. These short distances do not allow a battery to actually charge and you are using more power than charging. Where we live we are about 5 miles from most places we go. My last report was like 120 trips under 5km in 30 days. How did I Do that???? Drop off at daycare 3 (car odd)miles, from daycare to home 3 miles(car off) , to grade school after school 4 miles (car off), then home. That's 80 cycles for just school. If I go to lunch, 2 more short trips and throw in a drive to the grocery store, now were looking at 8-10 trips the burn the battery power than charge it.

The real killer is the heated seats, defrosters, A/C full blast on the short trips. I do take some 20-30 milers 1-2 times a week which helps but the cars still need the tender
I hear several people saying that using a battery tender makes a difference but I don't see how. I assume you mean driveability.

I have an '11 M3 with a little over 8k miles on it. I drive 1.6 miles to work. 2.9 miles to the gym and then 1 mile back home. This is 5 days/week plus a few miles on the weekends.

So far it still starts fine, the lights are bright, the stereo is loud, the heated seats keep my ass warm, etc.

With prior cars when the battery goes bad it won't start. What's different with the M3?