I've been getting a message on my SID saying that my key battery needs replacing. Is there a battery in my key? I know there's a micro-chip. I picked my car up from having it serviced the other weekend and used my spare to get in the car (had them lock the keys in it since I picked it up on a Sunday night) and when I used the spare key to start the car, it wouldn't start. I had power everything and after a moment of panic, the SID displayed a message saying the key was not recognizable. I then used my other key (that had been hidden ever so strategically under the mat) and the car started right up. So, I'm down one key and getting a message saying my other key is probably going to soon crap out on me. Is this something I can fix (are the batteries easily replaceable?) or will I have to send the key out?