Well if you want to join the Mugged Club, just cough-up like so many people do, but this PCN is outrageous, just a venal money-grubbing exercise. Trouble is, if you want to fight it, you must stand your ground and take them to London Tribunals and risk the full PCN penalty, where I would certainly expect you to win. All London councils are venal and rapacious and make millions from PCN penalties, and some make millions in double figures too.
https://www.timeout.com/london/news/the-london-boroughs-that-dish-out-the-most-parking-fines-032823So it's a Magic Money Tree for them and this means they refuse virtually all representations against a PCN.
I suggest you submit reps on the basis of
de minimis, pointing out that your car clock does not give seconds, only hours and minutes, and an error of 1 minute would be a reasonable error. Point out that there surely has to be some commonsense applied.