How many kWh do you need to charge an electric car?
You usually need to replace part of the battery’s energy, not its full capacity. The starting percentage, target and usable capacity determine the theoretical amount stored.
Energy stored = usable capacity × (target − starting percentage) ÷ 100. A 60 kWh usable battery needs 36 kWh to move from 20% to 80%.
A 40 kWh battery needs 24 kWh for the same percentage change; a 75 kWh battery needs 45 kWh.
In this guideChoose a section
01
Convert percentages into battery energy
Use the usable or net figure when it is documented. Gross or nominal capacity may include a protective buffer unavailable to the driver.
The capacity in a commercial version name is not necessarily the usable capacity. Check the catalogue notes when a value is indicative.
02
kW and kWh describe different things
kW is power: the rate of energy transfer. kWh is energy: the amount transferred or stored. A constant 11 kW for two hours corresponds to 22 kWh before any loss allowance. A battery’s energy capacity cannot be expressed in kW.
Three quantities can differ: energy stored in the battery, energy delivered to the vehicle and energy drawn from the supply. Conversion losses and the car’s auxiliary systems mean that not every billed kWh becomes stored battery energy.
03
Estimate supply energy separately
With an assumed 90% overall charging efficiency, storing 36 kWh requires 36 ÷ 0.90 = 40 kWh from the supply. The difference is 4 kWh. This is an arithmetic example, not a measured efficiency for a particular vehicle.
Real efficiency depends on charging power, equipment, temperature and other conditions. If the figure you have is already energy billed at the supply boundary, do not add the same losses again.
To estimate the energy to replace after driving, multiply distance by an appropriate net consumption figure and divide by 100. For 50 km at an assumed 18 kWh/100 km, the battery energy is 9 kWh. The estimate must still allow for the journey’s conditions.
More examples and detail
Examples from the expanded catalogue
Compare the figures
Battery energy stored in the 20–80% window, before charging losses
Škoda Epiq 40 · Italy 2026
- Usable capacity
- 37 kWh
- Energy stored
- 22.2 kWh
Škoda Epiq 55 Selection · Italy 2026
- Usable capacity
- 51.7 kWh
- Energy stored
- 31.02 kWh
Suzuki e Vitara 61 kWh 2WD · Europe 2025
- Usable capacity
- ≈ 59.8 kWh
- Energy stored
- 35.88 kWh
Comparison from the table in this guide.
| Version | Usable capacity | Energy stored |
|---|---|---|
| Škoda Epiq 40 · Italy 2026 | 37 kWh | 22.2 kWh |
| Škoda Epiq 55 Selection · Italy 2026 | 51.7 kWh | 31.02 kWh |
| Suzuki e Vitara 61 kWh 2WD · Europe 2025 | ≈ 59.8 kWh | 35.88 kWh |
≈ marks an indicative usable capacity. Use the correct battery and source market. Model records include English technical notes and original source links.
Specifications refer to the version, year and market shown. Model records have English notes; original source documents may use another language. They do not certify current availability in your country.
05
Sources and method
English editorial version updated 16 October 2026. Arithmetic examples are Ricaora calculations. Efficiencies, consumption assumptions and example tariffs are not measured vehicle results or current commercial offers.
Installation requirements and electricity contracts vary by country; use qualified local advice for the electrical system.