Got my new (used) batteries!! Now, how do I rejuvenate them?

Here is my wired-up Megawatt, if anyone wants to tell me I did something wrong before I glop it up with silicone :B

The AC cord came with the unit.

I have pulled hard on all connections and they are solid.

Any hints on setting the initial voltage before I start fiddling it?

(I can't seem to remember how to embed pics from imgur, or something has changed. I will look into it but so many chores today and I want to work on those batteries!)