If your car has no power but the battery is good, it could be possible that the issue is coming from a faulty starter or alternator. The starter helps to turn on the engine, and the alternator helps to generate electricity for the onboard electrical components. If either one of these components fails, then your car will not have any power. It might also be possible that there are other electrical issues at play, like a malfunctioning fuse or relay switch. A qualified mechanic should be able to investigate and diagnose what is causing the lack of power in your vehicle.