I was lazy, changed the SSID and password to the same as my old one. Not only would the car charger need an update, the inverter would (I have no idea how to do that), the secondary access point down the garden would need changing etc. My lazy work around.
As others have pointed out there is usually a method to get into the charger - either a reset of the charger and setup again or mine has a Bluetooth way in via installer app. So if you don’t take my lazy solution as above it will be charger specific.