SL/R230: How To Determine Age Of Starter Battery?




It will say something like "504", "204", etc.
Usually you can decipher the number like this.. the first number can be the month (504= May 2004) or the week of he year (204= 20th week of 2004 which is end of May)
Unfortunately you need to pull out the battery to figure it out.
Safest thing is to just replace the battery if you have owned the car for some time, don't know when it was changed, and plan to keep the car. These batteries don't give a lot of warning.. they just die.
I had a starting battery in my W221 (same battery) and thought it cranked and started the engine fine. A few months after buying the car, I saw that the trunk battery was brand new but this starting one looked pretty old. Bought a new one and saw the date code on the old one was 7yrs old.
Here's the thing though..although the old battery sounded fine to me, I realized that I had never heard a W221 start other than my own. The new battery cranks twice as fast and the car fires right up.
Now that I think about it, the old battery was on its last legs. But I had no way of knowing that till I replaced it! People heard that I was gonna replace it and said "why, there's nothing wrong with it.. don't waste $!". They were all wrong...
Good thing I replaced it before winter. Would be surprised if it would have made it through the winter...



