How to read Stamped Date Code on Marine Battery

[Searaider 2]

Hi Gang .
Can someone help me out ?
I have a pair of Centery Marine Pro 600 Batteries in the boat & am trying to figure out how you read the Date / Code Stamped on the top of them .

I'll use the Stamp Markes from one of them as an example .
Note :-
I purchased the battery on 13-04-2005.

It has 2 seperate sets of stamps on it .
First One is Stamped near the + Pole is :- D24AJ

Second one is in about the middle of the battery between the + & - Poles is :- D7M4C

Thanks in advance

[Kevin Ferguson]

Searader2
the stamp near the post is a wetdown code which denotes the shift date month and year that the battery was charged . Other code is a manufacturing code for the " dry " battery . Similar info . includes assy line info.
Cheers Kevin

[snasman]

Most automotive centuary batteries have the month and year stamped into the posts ie on the neg theres a letter and on the pos there is a number so with the lettering a7 that will make that a January 2007 battery the lettering goes up with the month example A = Jan ,B =Feb and so on,like I said I know this is the case with Automitive batteries marine may be different. But the bottom line is your battereies are getting close to four years old so its time to replace them,good luck.

[Kevin Ferguson]

The stamp in the post is a point of sale code and was used as a reference point for warranty claims. As stated this was a month / year code. This practice should now be discontinued.
Cheers Kevin

[Searaider 2]

Hi Kevin & snasman ,
Thanks for the feedback your info has clarified on how to read the codings .

snasman ,
As you say its time to get new batteries .
I normally change them every 3 years , but this time the years have got away from me .

The reason I asked the Query is so that I can identify the age of any new Batteries I'm going to buy .
Its probably not an issue due to fast sale of New Batteries , but if there are a couple to choose from sitting on the shelf , you may as well try & get the Newest one you can .
IE- 1 could have been sitting on the shelf for 6 months & could effect the usable life of it .

Thanks again guys .

[Kevin Ferguson]

Searaider 2
cannot remember if these are a 12 or 24 month warranty , but either way 4 years is a good run. Are you looking to replace solely on age or have you noticed a drop in performance? If performance is ok , a full charge and check with hydrometer & volt meter will give some indication of condition. After charge S.G. should be 1260 @ 25*and volts 1265. Leave standing after charge or you will get a higher volt reading due to surface charge. Electrolyte should be around 20mm above the plates. As a lead acid battery for the marine enviroment the MP600 would be considered a premium product. You would probably need to start looking at Gel or AGM for any improvement.
Cheers Kevin

[Searaider 2]

Hi Kevin,
I'm going to change them purely due to their age.
I try & fish offshore when ever I can & to be on the safe side, I usually change them after 3 years.
May be an overkill but I think , to be safe , it warrents any additional costs in changing them early ?

Thanks again for the info