I'm thinking there must be more to this discussion, besides what is being posted. One thing I believe I remember from (very) old posts on this, there is at least one charger that might have a risk of starting a fire. And, I believe it's the one from wallyworld for a little under 20 bucks. I have one of these, and use it, but always while being watched. I never leave it unattended overnight.
Another thing I recall, if it's an Optima, I believe there are unique considerations (which I do not recall). There is a 'Dick Flynn' article in an old V8 Times on this. And, I believe this info can also be found with a google search. The Times article appears in the Jan/Feb 2012 issue.
And, since someone mentioned Battery Tender, and because they advertise heavily in places like Hemming's (and the Times), I will add that I live in a 'winter-area' where lots of folks have batteries on float-charge for the winter. Battery Tender is the only brand sold by our only local source, and many folks here are using it. I've never heard of problems with it. (This would be for ordinary lead-acid batteries. I'm not aware of any locals besides me using an Optima.)
Just opinion - I have almost no experience. For my case, I put my bats on a short charge, a few (2-3) times over the winter. Seems to work for me. As for the Optima, I have one, and I don't charge it over the winter.
