From all the posts I've read from members who are able to support their views, no. The initial 8hr spiel is not needed.
From my own personal experience with 510 manual
batteries, the initial 8hr charge routine accomplishes nothing other than having a green light on your charger for an extended period of time.
Provided there is no problem w/ the charger, when the light is green the battery has all the charge it's going to get/take.
Are you having a problem with the battery you are putting in the charger? When attached to an atomizer does it work?