Hello, my 2006 Porsche Cayenne turbo was about 1.5 months unused in the hall. After that I wanted to connect my Ctek charger, because the car was completely powerless. Result: The (correctly connected) charger only indicates that it is switched on and after some time goes into a kind of standby mode – as if no battery was connected. The charger is fine and charges just another vehicle without errors. Even with completely defective batteries it showed so far The battery in question is 1 year old and has never been deep-loaded, there is no frost in the hall. Can a car battery (without being hacked with the axe ;-)) break so that it is not even possible to use a circuit? Or is the problem in my car elsewhere? In the Cayenne, the battery is hard to access under the driver’s seat, which is why it is not yet available. but the charger was connected via the intended poles in the engine compartment. Thank you for your support!