Gel Battery age

How can I determine the age of my battery? BC23JX6VYK3J

If that is a Victron battery it should have a label with a serial number starting something like HQ2435…. Where 24 is the year 2024 and 35 is week 35 which is the last week in August.

Do you think this means December 2013?

No idea, they are older than the HQ serial number format.

Or week 13 from 2012…
Anyway, considering what has been said above, maybe it’s time for a change if it doesn’t hold charge or shows sign of fatigue…

Looking at other pictures on the net, it could be year-week.

Newer ones have the HQ markings…