Payment models and pricing
Per kWh, per minute, subscriptions and idle fees.
You'll learn
- Explain payment models and pricing clearly and accurately
- Read the numbers that define the behaviour
- Apply the idea to a real charging session
Overview
Pricing structure matters as much as the headline rate, especially for a car that charges slowly.
In depth
| Model | Good for | Watch out for |
|---|---|---|
| Per kWh | Everyone — it is the fairest | Nothing much |
| Per minute | Fast-charging cars | Slow cars pay far more per kWh |
| Session fee | Large top-ups | Punishes small charges |
| Subscription | Frequent users | Break-even needs real volume |
| Idle fee | Bay turnover | Set a departure alarm |
Calculator
Charging Cost Calculator
What a session costs at the wall, including charging losses.
kWh
% SOC
%
per kWh
Energy into pack
36.0kWh
Energy billed
40.0kWh
Session cost
4.80
Formula
cost = capacity × ΔSOC ÷ 100 ÷ efficiency × priceYou pay for energy measured at the meter, not the energy that reaches the cells. Dividing by efficiency accounts for the difference.
Example: 60 kWh × 60% ÷ 0.9 = 40 kWh billed. At 0.12/kWh overnight that is 4.80.
- AC home charging is typically 85–92% efficient end to end; DC rapid is 92–96%.
- Some public networks bill by time, which penalises cars that taper early.
- Compare against fuel using cost per 100 km, never cost per fill.
Per-minute pricing punishes tapering
On a per-minute tariff, stop at 60–70%. The last twenty percent costs the same per minute but delivers far fewer kilowatt-hours.
Key takeaways
Remember this
- Per-kWh pricing is the fairest model.
- Per-minute tariffs penalise slow or tapering cars.
- Idle fees exist to free bays.
Mark this lesson complete
Confirm you've read through and we'll count it toward your progress.
Was this lesson helpful?
Rate this lesson