I've owned my Octy iv Estate PHEV since October 23. Not only have I experienced the same (or similar) 12v battery problem, but also an absolute shed load of other problems. I've loved Škoda cars since I bought the first vRS in 2001, but this latest version has really knocked my faith in the marque. Initial problem, charging cable wouldn't lock into the charging port, so charging unit wouldn't operate. Called Richmond Škoda who gave me an appointment for 3 weeks later and told me just to drive on ICE in the meantime....... of course, 2 days later, car wouldn't start, 400v and 12v batteries both flat, so called Škoda Assist who attended within the hour. Technician was great, sorted the problem temporarily by jump starting the car which reset the charging unit and allowed me to charge the car again. He was incredulous that Richmond Škoda obviously had no idea that this was a fault that needed to be dealt with immediately and didn't realise that the 12v battery would die quickly. Since then, multiple intermittent faults with the particulate filter blocking, the front assist de-rating (particularly when it's cold or wet) and the latest, a regular fault message that the "climate control system has shut down. Fault with on board charger unit." Dealer insisted that they couldn't find any errors, so I invested in a Vcds diagnostic system which picked up numerous error codes, most but not all of which are "generic can-bus errors". Presented the printout to the dealer who looked again and told me that "all modern cars tend to have lots of errors which aren't important." So, no solution to any of the issues so far, other than don't buy another PHEV or electric Škoda until the dealers are properly trained.