Don’t open the car anymore!

Hello, I can’t get my car open anymore. The battery was empty these days and then the door Mehanisch opened…without central lock. Then I charged the battery and everything was normal again. Then I left the car for 3 days again and the battery is probably empty again. Anyway, I can’t get a door open! It just clicks…as if there’s still some juice on it, but that’s all! Is there a trick to get the doors in? but only the one. Who can give me a tip?