Persiman

Good afternoon, men. 07 F150 screw 5.4 purchased used has a Duralast Gold 65-DLG battery. It looks like the stamped production code is

3M20CM9A
How old is this battery? Autozone staff say "if you buy your battery here, we can always look it up for you". They think it's a Johnson Controls battery.
Any assistance appreciated.

bajaman

That is more like a serial number I believe...typically Duralast have a conventional date code, like 0419 would be April of 2019. Usually just a decal/sticker so...if missing it may be difficult to decipher age.

tuflehundon

This. Every battery I have bought from Autozone has a small round date sticker on it that say the date in a standard format, like 10/21. I could take a pick of mine of needed. I currently have a Duralast Platinum AGM battery in the truck.

Persiman

See attached decoder. The first 2 digits are the date. The 3 means 2013, and the M means December (12th letter if you skip i). So, December 2013. So, yeah, when starting issue show up, it will most likely be the battery.

That's a very long-lived battery, in my experience.

(The round sticker must have been cleaned off by the engine detailer. They're helpful when they're there.)

Thanks for the comments and suggestions.