Car radio does not store transmitters

I have a problem with my car radio. I can save all the transmitters without any objection, but when I turn off the engine and the key indicates the stored transmitters are all gone. Thought it was on the radio first, but with my new one it’s like that. What’s the problem. My father meant that it somehow has to do with the electricity?!?!? Hope you can help me [translated from motor talk from the topic ‘Radio does not save transmitters’.]