Winter storage battery issue
I'm about to get ready for winter storage. Now, it was in the 50's for one week, then in the 30's, and I didn't drive my car for 10 days. When I finally went to take it out, I had one hell of a hard time starting it. I thought I'd have to jump the battery it sounded so sick, but I did manage to get it going. Took about 10-12 minutes for it to fully warm up and I didn't have to keep giving it gas (after 3-4 minutes). When I pulled out of the garage I noticed a liquid trail that appears to have come from the battery compartment. In those 10 days I'd swear the battery went dead because my radio lost its settings and only does that when the car loses power.
So, for winter storage, if I can't plug the battery into something (the garage where I rent has no electricity), what is my best course of action to keep the battery going?
I plan to go over every 2 weeks or so and start up the car, run it 10 minutes, drive a few miles, then fill up the gas tank (yea, a few ounces) so the tired won't flatten, all parts will move, etc. But this battery issue worries me.
I do have a booster thingie I keep in my trunk (and yeah, I know it runs down if you never use it, so I think I'll keep it in my house and just bring it over when I start it up) but is that wise to do, jump it every few weeks?