Nowadays air temps are between 0 and 30. But I have to leave the car for two weeks at an airport parking lot. Am worried of flat battery once I return. Any suggestion on how to avoid? How about removing the battery and keep it inside the car (which would be warmer) during the two weeks?

 

id disconnect the batterie put it in trunk or something and then pull out a couple things so it wont get stolen i.e take spark plugs put them some where hidden in car

 

I hear people just swapping out their plug wires.. but then again you have that coil on plug ignition i guess.

Could pull your fuse to your fuel pump, thats replace it with a broken one just to look "normal" or just leave it bare. Either way, car ain't going anywhere without it working, and if someone has to take that much time jacking with it, he will move on to the next car.

my .02.

 

You should check to see if the parking lot has provisions to use the block heater and plug your car in. if so that's all you will need. I live in Labrador where it is -40 to -50 degrees for about 3-4 months in the winter and i have yet had a problem with a frozen battery unless it had been completely drained before. if your battery has been working fine it shouldn't pose a problem.

but you can get a voltage trickler that you hook up to your battery and will induce a little charge to it over time and keep the battery charged and healthy, but i'm not sure if it would work in your case.

 

Just get one of these and be done with it: THIS THINGY HERE

You can either make your own, or pick one up at any auto parts store.

Just an idea.