Mike,
I have the smaller version of the Black and Decker charger. It does do a maintenance charge.
Do you have the equipment, or can you get your local bike shop to check out the charging system.
Just trying to rule out all the possibilities here.
I think that if you do go with the OPTIMA that you should go with the yellow top, deep cycle, battery. As that is what their site recommends.
Let us know what you decide and how it works out.
Steve