New battery after only 3 years?

[the Ferret]

My experience with these AGM batteries is one day they are good, the next day they are dead, you throw them on a charger and even though the charger shows them as fully charged, they are really dead. Had that experience on 5 bikes now. I just replaced my 5 year old battery in my ST even though it was still working, because unlike the CB, the ST weighs 717 pounds and not easy to push and jump on to bump start. I'll risk it on the CB, but not on the ST. 5 years out of a battery was good enough for me.

Btw just replaced the battery in my 6 year old Ridgeline for the same reason.