never noticed a date on mine - these are AGM batteries they dry out and can't hold the charge....
the top where you'd expect the 6 cells lids to hide - can be easily unglued - to find 6 black rubber covers. When u pop these off look inside and if you see the plates it won't hold a charge - std distilled water just enough to make the matting swell back up in each cell might make it happier - u r not after a puddle on top - just not a bone dry cell making continuity by magic....
NOTE unlike the odyssey the motobatt plastic lid will not clip back in place - I guess silicon just to hold it down - or glue if u expect a fight next round
did my odyssey one like this, after it just stopped cranking the bike - 5 years on still going - although checked this winter and it was bone dry again, so I topped it up again....
will need to check again in a 24hrs then give it a charge then check its mildly moist and off you go