As above. If I park the car and leave it for maybe 6 months, how long might the battery last? 2019 Leon Cupra 290. Will be left outside - no possibility of connecting a trickle charger. Our ancient Renault Laguna diesel would always start after 6 months, but I'm assuming the Seat with all its electronics won’t be quite as accommodating. I have one of those portable car starters, which I'd hope might be able to start it.