most likely is exactly how you wired it. The main power of the stereo needs to be wired to the acc cable so when you turn it off it shuts down all the power. Then there is a memory cable this one can go directly to your battery. This is the one that holds your stations and time. I had wired my stereo to the battery directly and that is what was killing it. This of course back when I had my VTX with a fairing and stereo.
Batteries Plus has a duracel that I use in the Harley and it has a 2 year warranty. Once you get your gremlins worked out I would recommend getting a better battery warranty just in case that's not it.