Seat Cordoba 6K2 draws battery empty

The Seat Cordoba (now the 6th owner) should not be left standing anywhere for more than 5 days, otherwise the battery is completely empty. Every day I have to drive a few km with it, maybe even just switch on/off once, I have not yet tested. All consumptions are locked off test by test, rest current always around the 10-20 mA. Nevertheless, the battery does not last. Until I decided to drive with the car regularly the ADAC had to give 4 times starting aid. R The voltage when the motor is switched on in the empty run is exactly 14.3 volts. The current at the plus pole by means of current pliers measured at only 0.6 amperes. Then you still wonder why you get the feeling that the battery is not being charged properly. The battery was also changed at the beginning of spring. Didn’t help much. So that I don’t have a new battery or a new one now. I would first like to know what the reason could be for the low current of 0,6 A in idle mode. I don’t want to do research anymore, so I ask, for example, how to test cables on resistors. This is also unnecessary again. The voltage is constant at 14,3 V. Rest current very low. Even if everything is disconnected, the battery discharges. It is interesting to disconnect the battery after switching off the motor. The battery lasts for a long time. slow there are only contradictions. Maybe there is still a current hole. Maybe the battery is broken? I am primarily interested in the low current.