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EV & CarsGenerated accuracy model review: 2026-05-06

EV Charging Time Calculator accuracy and testing

This page documents how Calwarden builds trust for this calculator: source notes, regression-style default tests, limitations, assumptions, unit handling, rounding, and visible change history.

Formula source

  • Charging hours = battery kWh * (end percent - start percent) / (charger kW * efficiency percent / 100 / taper factor).

Test cases

Default input regression check

Generated from the checked-in default inputs and calculate function.

Inputs

  • EV Model Preset: Tesla Model Y Long Range planning - 75 kWh, 3.8 mi/kWh
  • Battery Capacity: 75 kWh
  • Starting Charge: 20%
  • Ending Charge: 90%
  • Charger Power: 11 kW
  • Charging Efficiency: 90%
  • Taper Factor: 1.15 x

Expected outputs

  • Estimated Charging Time: 6h 6m
  • Charging Time: 6.1 hours
  • Battery Energy Added: 52.5 kWh
  • Effective Charging Power: 8.61 kW

Known limitations

  • This page documents the checked-in calculator logic and does not certify results for every real-world edge case.
  • Use the result as a planning estimate unless the calculator page states a stricter purpose.

Assumptions

  • Charging power is treated as average usable power after the taper adjustment.
  • The calculator does not model vehicle-specific charge curves.
  • Calculations run locally and are for planning only.

Unit handling

  • EV Model Preset accepts one of the configured options.
  • Battery Capacity accepts values in kWh.
  • Starting Charge accepts values in %.
  • Ending Charge accepts values in %.
  • Charger Power accepts values in kW.
  • Charging Efficiency accepts values in %.
  • Taper Factor accepts values in x.
  • Charging Time is displayed in hours.
  • Battery Energy Added is displayed in kWh.
  • Effective Charging Power is displayed in kW.

Rounding rules

  • Number displays use up to 2 decimal places in the calculator UI.
  • Input precision follows configured step values where provided.

Version history

1.0.0 - 2026-05-06

Generated accuracy and testing page from the current ev-charging-time-calculator calculator definition.

Change log

2026-05-06

Published default regression test documentation and metadata fallbacks for EV Charging Time Calculator.

Calculator transparency

Accuracy pages are generated from checked-in calculator definitions and can be upgraded with curated review metadata over time.

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