S500nubie

Hey everyone. I am very novice but not about cars. More Chevy guy old ones. I was given a very nice 00 s500 with the chrome circle panic button key. I started this car every other day for about a year. Smh I dropped the key many times. Until the key wouldn't do anything and had something loose inside. The IR coil and seems like a small eye at the tip had come off. I ordered a new coil and installed it with thermal adhesive witch allows for current to flow. It unlocks the door now and locks ..pops the trunk. I suspect the battery is now low. I will purchase one tomorrow. I can put it in the ignition and no click but I can unlock and lock the doors with it inside the ignition. Any thoughts would be greatly appreciated. The air system has sat the car low and I am not in any position to have it towed like the way it is and dealer wants to see the car. Please someone help. Thanks for reading and any input would be greatly appreciated.