Octopus and OVO also offer EV tariffs where you get a cheaper kWh price if you let them control when your EV is charged. You can always override the smart charging but you pay the standard rate.
* https://octopus.energy/smart/intelligent-octopus-go/ - 7.5p per kWh
* https://www.ovoenergy.com/electric-cars/charge-anytime - 7p per kWh