Hello, how long do the A3 batteries (MJ 2012) last on average? Today it was about 18 km. After that car was parked briefly. When I wanted to start, the hands in the instrument cluster shrugged wildly up and down and the starter died immediately again. Keys out and started again, then the car jumped on. Probably indicates a weak battery, right? Car is usually rarely driven further than 25 km at a time (on day 50 km).