On additional suggestion. If you remove the battery and bring it inside, or some place away from the car, and put that trickle charger on it, you not only keep the battery in good shape, but if anyone decided they wanted it and tried to steal it, chances are they are not going to have the right battery with them.
You might want to save some money as well. Call your insurance company, you may be able to cancel some parts of your insurance. Maybe even the collusion (your car is not likely to collide with anything if it has no battery. Keep comprehensive for things like fire.