Battery dead after a 2 weeks in the garage

[keysguy]

I have found my battery only last about two weeks sometimes too. I had to get a battery maintainer. The reason I think my battery life is so short is that I only put about 20 miles a week on my car. I don't think with using the alarm and only driving it for 20 miles a week is enough to keep the battery charged. The one I use is from Battery Tender. http://batterytender.com/products/automotive/battery-tender-plus-high-efficiency.html

I plug it into the cigarette lighter/ accessory outlet and run the cord outside the door then shut the car door. I put the charger/maintainer on a brick under the car and run the extension cord to it.

[kindlethespirit]

My S has been parked since October here in PA. I haven't used a tender and typically I start the car once a month and allow it to run for 30 minutes to get the oil hot.

I've never had any issue with a flat battery even when we've had minus zero temps for weeks at a time.

On another note, Keysguy---I have a house in K.W, but haven't been able to get there this winter. How long have you been in the Keys?