So a couple of days ago my car's aftermarket navigation stopped working. I thought it was broken so I was flipping out. I had it installed about 6 months ago without any hitches. I hadn't been blasting music with my new system so it never was an issue. I walked out to my car this night because I was supposed to drive someone home, but my remote unlock didn't work. I guess what I'm asking is whether my battery is DEAD or SHOT. If it is shot, what can I do to prevent this from happening again? I have heard of yellow top batteries? Help would be greatly appreciated. Thanks in advance.

 

Sounds like a dead battery. There could be a draw on it from a bad component. If it's old, it probably just needs replacing. I hear Interstate makes the best batteries, and they are just relabeled for Lexus if you buy the OEM one.