The same car, the same efficiency, four ways of paying for the energy. The spread between the cheapest and dearest row is far wider than the difference between any two electric cars — which is why where you charge decides an EV's running cost more than what you drive.
Everything on this page comes from two ideas. A charging session is limited at every instant by the lower of what the post can supply and what the car will accept, and the car's willingness falls as the battery fills. Cost per mile is then just the price of a kilowatt-hour divided by how far the car goes on one — after paying for the energy that never reaches the battery.
Power into the battery at any state of charge is
min(charger kW, vehicle accept kW) × charging efficiency. Integrating
dE / P across the window gives the time. On AC the onboard charger is the ceiling and the
curve is essentially flat; on DC the car holds close to its peak to a knee around
50–60% state of charge, then tapers to roughly a sixth of peak by 100%.
cost per mile = price per kWh ÷ (miles per kWh × charging efficiency). The efficiency term is
the part people leave out: your meter bills the energy drawn by the charger, not the energy that
arrives in the cell.
A 60 kWh family EV at 3.9 mi/kWh, charged from 10% to 80% on a 150 kW rapid, takes about 25 minutes and needs roughly 45 kWh billed for 42 kWh delivered. On the same charger, the 80–100% stretch takes another 21 minutes — nearly as long as the first 70% — for 12 kWh. At UK off-peak home rates that car costs about 2p a mile; on public rapids, about 22p, against roughly 15p for a 45 mpg petrol car.
Because a nearly full cell cannot take current as fast without damage. Charging runs at near-constant power to a knee, then tapers so voltage stays inside a safe window. On a 60 kWh car at 150 kW the last 20% takes about as long as the first 70% — which is why the advice is to unplug at 80% and drive on.
Only if your car can accept more than 150 kW. The session runs at the lower of the two limits, so a car peaking at 120 kW charges at exactly the same speed on both, and you may pay more for the privilege. The car is usually the bottleneck, not the post.
Public rapid electricity is several times the price of domestic electricity, and an EV's efficiency advantage is not large enough to cover a tenfold price difference. In the UK, charging exclusively on rapids typically costs more per mile than a reasonably economical petrol car. Charge at home and it costs a fraction.
Yes. The meter counts what goes into the charger, not what reaches the battery. Roughly 12% is lost on home AC charging and 6% on DC rapid — cooling, the onboard charger, and conditioning the battery. Every figure here bills you for the losses, because your supplier does.
Two reasons, and cabin heating is the bigger one: a petrol engine heats the cabin with waste heat it has anyway, while an EV pays for every kilowatt out of the same battery that moves the car. The pack also has to warm itself to charge and discharge properly. Expect consumption around 25% higher near freezing.
Representative vehicle classes rather than specific models — battery size, efficiency and peak charge rate are typical for the class, not a manufacturer figure. The charge curve is a smooth two-segment approximation of a real curve, which is stepped and chemistry-specific. Prices are editable defaults, not live tariffs. Battery degradation, preconditioning, standing charges, subscription fees and queueing are not modelled.