Set up a known charging scenario
Use this tool to compare supplied AC charging settings for a known vehicle. Confirm usable capacity, the vehicle's AC input limit and a relevant efficiency value before calculating. The two power values must describe the same AC-side connection; efficiency accounts for the energy that does not become stored battery energy.
State of charge is treated as proportional to usable energy. Capacity ageing and the vehicle's displayed charge estimate are not modelled. Inputs and results stay in this page and are not saved or transmitted.
Method and worked example
Battery energy ΔE = usable kWh × (target % − starting %) ÷ 100. AC power P = min(available station kW, vehicle AC input limit kW). With efficiency η = efficiency % ÷ 100, AC energy = ΔE ÷ η and time in hours = AC energy ÷ P. Modelled battery power is P × η.
Example: a supplied 60 kWh usable battery going from 20% to 80% needs 36 kWh stored. With 8 kW available, a 10 kW vehicle AC input limit and an assumed 90% efficiency, the model uses 8 kW, 40 kWh at the AC connection and 5 hours. These are illustrative inputs, not vehicle specifications or recommended settings.
Precision is retained during arithmetic. Results display three decimal places, or scientific notation for very small or large values. This numeric precision does not establish the accuracy of the charging assumptions.
Where actual charging differs
The vehicle controls its charging rate. Battery temperature, state of charge and vehicle limits can reduce accepted power; station power may also change. The model does not simulate these effects. A target of 100% still uses constant power here, so it is especially important not to treat that result as a full-charge promise.
DC fast charging, battery conditioning, charge scheduling, interruptions and changing EV energy-management allocations are outside this model. It does not select a circuit, breaker or conductor, approve an EV installation, or establish available service capacity.
Common questions
Why does a higher station rating sometimes make no difference?
The calculation uses the smaller supplied AC power limit. Raising the station value above the vehicle's AC input limit leaves the calculated power unchanged.
Can I use gross battery capacity or a DC charging rating?
No. The model needs usable battery energy on the same basis as the charge percentages, and both power inputs on the AC side. Check the manufacturer's definitions rather than mixing unlike ratings.
What efficiency should I enter?
Use data that defines stored battery energy relative to energy delivered at the AC connection for the relevant scenario. Do not substitute motor efficiency, driving efficiency in kWh/100 km or an unverified generic percentage.
Related tools
Sources and model scope
AES Engineering Ltd., Electric Vehicle Charging Performance Requirements: A Scenario Analysis (2021), section 2.1.2, printed page 8: energy accumulation from power, charging efficiency and elapsed time. This tool uses a constant-power simplification, not the report's time-step or load-sharing simulation. The SOC-to-energy step is an explicitly linear modelling assumption.
BC Hydro, How fast your EV can charge: vehicle charging limits and the effects of temperature and state of charge. Nissan Canada, 2026 Nissan ARIYA press kit, charging notes: actual charging varies and usable capacity is lower than total capacity. No vehicle-specific defaults are imported.
Sources checked November 9, 2026. Report a problem or suggest a source; inputs are not attached automatically.