Man, do I like the charger/maintainer that I had bought not too long ago, and installed. It has gotten to the point where I seldom see it giving my battery a quick hit. And I can let my Miata just sit there, unused in the garage for a good two weeks, and when I turn her over, it cranks up just as quickly as I had just taken her for a long spin, or driven it daily.
I have had many cars in my 58 yrs. and never seen batteries that can deplete so easily by non use after just a week or two. Must be the designs of these not too much bigger than a Harley motorcycle battery. They must have been able to find enough room for a REAL car battery in these things>>LOL.