Octopus Intelligent is 7.5p per kWh from memory.
0.075 x 77kWh =£5.775 (100% charge)
Although you only charge 20- 80% most of the time. You can also work out the cars effeciency per 100 miles but you would need to ask those with an Enyak what there effeciency they are getting 🙂