As the manual warns, and I have experienced, leaving the key fob in or near the car can drain the battery quickly. The car stupidly keeps querying the key until it dies. At my house, this is a particular problem because my closet is directly over the garage, I leave the key in my pants or on the shelf in the closet, and the MS vampire sucks the juice out of the key fob battery. I have tried leaving the key fob in my office, but I should be able to just follow normal habits of emptying my pockets onto my closet shelf; I have learned to leave the spare key out of range. I have now replaced my third key fob battery in 10 months! First the work around: For those on Amazon Prime, Sony CR2032 Lithium 3V Batteries (10 for $4.91) will get you replacement batteries for under $0.50 each with free shipping. I leave some in the glove box and where I keep other batteries. Just like Tesla is working to drive a stake in the heart of the main battery vampire, they need to work on the key fob vampire. If the car is not moving for a while, most systems are shut down, and positive responses keep coming from key fob queries, then the MS should greatly reduce the query rate of the key. This can go back to a normal rate when something happens like a door is opened, the charge cable is removed, etc. Who knows, maybe the upgrades taming the main vampire in 5.0, will help tame the key fob vampire. Maybe the system that is doing the key fob querying will be shut down as part of getting rid of vampire loads. On the other hand, I hope that my closet key fob will not keep the main battery vampire awake.