The average EV usable battery size is 62.5 kWh, so we can use the formula of:
Electricity unit rate (enter as 0.189p) x battery size (62.5 kWh) = cost to fully charge: £11.81
This formula can be applied to any EV - you just need to make sure you’re using the right electricity unit rate and the correct battery size.
We can also work out the cost per mile by dividing the charging cost by the real-life distance the car can travel. The Honda e has a real-life distance of 105 miles on a full battery, so we would divide 5.38 by 105 to get a cost per mile of 0.05p.
The best time to charge your car will be during off-peak hours if you get an EV-specific tariff. The costs listed above can come down even further if you sign up to a time-of-use energy tariff. These are designed to help energy customers save money by offering cheaper electricity at certain hours of the night (e.g. from 12am to 4am). Some energy suppliers offer as little as 4.5p per unit of electricity during these hours, though most cars will need longer than the cheaper time period to fully charge.
Nevertheless, we see how the overall charging costs come down with that lower unit rate:
These time-of-use tariffs are often marketed specifically as EV tariffs to entice EV owners to sign up to them, and present the most affordable way to charge an electric car at home. The flipside, though, is that suppliers charge much more for “peak” electricity in order to make up the shortfall caused by the off-peak hours. You therefore have to be disciplined about your energy use and know exactly what your overall spend is likely to be.
It’s easy to get a home charger installed as long as you have somewhere to house it - most people put theirs on the garage wall. Delays can come as a result of backlogs that the installer is experiencing as more people book their installations, or on the day when unforeseen issues arise in terms of structure or where the cables need to go.