My Renault Zoe 2014 plate had a complete power failure at the weekend. Renault are saying that the 12V battery needs replacing but are now saying that it needs a major software update which would take 3-4 hours and cost me £379!! I did an update 1.5 years ago when prompted by Renault but where has this come from?? Why am I having to pay for them to update my Zoe? And if it’s something they have to do why isn’t it factored into the yearly service? Advice gratefully received.