Battery date of manufacture

[Ronzi]

I was under the impression that battery life is more dependant on usage than just on time. In other words the projected lifespan of a "48 month" battery is predicated on the expected usage of the vehicle during that time.
A battery in a low-mileage car could last far beyond 48 months, while one in a high-mileage car would not.
I'm not arguing against replacing an old battery, just that age is not the sole determinant of how long a battery will last. It it were, the length of time the battery sat on the shelf before being installed in a vehicle would have to be taken into consideration as well.

[Brucelee]

The battery in a low mileage car will need to be replaced sooner, not later. In fact, Porsche will NOT warranty a battery on a car unless it has been driven at least 10K miles per year (according to my service rep).

If you let your Porsche sit in the garage, the battery is one of the first things to go.

This is more so now that modern cars use a fair amount of juice just as they sit there.