How it is calculated
- Battery energy added = usable capacity × (target state of charge − starting state of charge).
- Estimated range = energy added ÷ consumption × 100. Estimated time includes a simple 12% allowance.
02 · Charging
How much range could a session add?
Estimate the energy, driving range and time associated with a chosen battery charge increase. This is useful for checking whether an overnight top-up is broadly sufficient; it does not model a vehicle's charging curve.
Your inputs
Get your result
Use your own figures or load the worked example below. All calculations stay in this browser.
Real charging time changes with temperature, battery state, vehicle limits, charger sharing, and losses.
How to use this tool
- Find the vehicle's usable battery capacity and a realistic consumption figure.
- Set the starting and target percentages; the target must be higher.
- Enter sustained charging power, calculate, and compare the estimated time with your available charging window.
Worked example
A 30% to 80% home top-up
- Usable battery
- 75 kWh
- Starting charge
- 30 %
- Target charge
- 80 %
- Consumption
- 18 kWh / 100 km
- Charger power
- 11 kW
Expected result 37.5 kWh added · about 208 km · about 3.8 hours
75 × 0.50 = 37.5 kWh. At 18 kWh/100 km this adds 208.3 km. Time is 37.5 ÷ 11 × 1.12 = 3.82 hours with the model's 12% allowance.
Transparent estimates
How to read this result
Energy added is stored in the battery; added range is a consumption-based estimate. The time assumes steady power plus a 12% allowance, so rapid charging near a high target can take longer.
Assumptions
- The charger is assumed to deliver its stated power throughout the session.
What this estimate cannot tell you
- Charging curves taper at higher state of charge; temperature, vehicle limits, and AC/DC losses can change the result.