I often use the Tesla superchargers when charging the Funky Cat, as they are often significantly cheaper than other public chargers. The last time I used the chargers at Cribbs Causeway I had an issue with one of the chargers so I missed the cheaper charging window.
On my way up the M5 and needing a charge I tried again, though this time I arrived with about ten minutes to spare (not quite the fifteen I planned for). However this time I used the charger that worked last time first and it just worked. This meant I got my charge at 32p kWh rather than 56p kWh. This saved me over nine pounds on my 39kW that I put into the Funky Cat.