Battery date of manufacture

[RandallNeighbour]

Discovered last night that the battery in my 1998 was over 5 years old. Replaced it immediately. They just don't last that long on average.

Just for an FYI, the way to determine the year and month of your battery's birth date is to look at the top of the negative post. Stamped in the lead are four digits. The top two are the year (My 2000 battery had "00" inscribed on it). If yours has 02 on it, then it was manufactured in 2002, etc.

The lower numbers are the weeks of the year. My newish battery showed "04" (a 2004 battery) and the lower numbers were "22", indicating the 22nd week of 2004 as the born date.

If you bought your Boxster used and haven't had to replace the battery, now's as good a time as any to pop the front trunk, remove the plastic thumb screws, lift off the center plastic cover, and examine your battery to see when it was born. If it's 4-5 years old, it's not a bad idea to replace it so you don't get stranded.

PS - Do be prepared for a thinner wallet... Porsche batteries are well over a $100 bucks, and you should certainly replace it with a Porsche battery so it doesn't slide around. Most non-Porsche batteries (Sears Diehard, etc.) don't have that lip on the bottom that allows for a secure fit.

[Brucelee]

Costco and Auto Zone both sell aftermarket batteries with the famous lip on the battery.

The Costco one is $47 with no core charge. Auto Zone is about $64.

The Porsche OEM battery is over $100 and is (IMHO) a piece of garbage.

Remember when swapping batteries, you will lose your radio, so you will need the code to recode it upon start up.

[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.