My 2002 S500 Mercedes remote key

This sounds like you need a new battery. It can be old and worn out or even damaged.

Thanks for your answer, but I changed the batteries by new ones from Mercedes parts, and the problem continued

Its the ignition switch going bad. Put the key in pull it out , it works then ten minuets later it does not ( O NO). When its warm out its usually fine.

I bet u it’s the battery to the car key same thing was happening to me! Idk or ever heard it the car battery because if that was bad the car would have no power