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EV & CarsGenerated accuracy model review: 2026-05-06
Home vs Public EV Charging Cost 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
- Home cost = battery kWh / (1 - loss) * home rate. Public cost = battery kWh / (1 - loss) * public rate + session fee.
Test cases
Default input regression check
Generated from the checked-in default inputs and calculate function.
Inputs
- Battery Energy Added: 50 kWh
- Home Rate Preset: eia_us_residential_average
- Home Electricity Rate: 0.16 $/kWh
- Public Charging Rate: 0.42 $/kWh
- Public Session Fee: $1.5
- Charging Loss: 10%
Expected outputs
- Cheaper Option: Home charging is lower
- Home Charging Cost: $9.16
- Public Charging Cost: $24.83
- Cost Difference: $15.68
- Effective Public Rate: $0.45
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
- All prices and vehicle assumptions are user-entered.
- Charging loss is modeled as a simple percentage.
- Calculations run locally in your browser and are not stored by Calwarden.
- Results are planning estimates, not financial, tax, insurance, legal, or mechanical advice.
Unit handling
- Battery Energy Added accepts values in kWh.
- Home Rate Preset accepts one of the configured options.
- Home Electricity Rate accepts values in $/kWh.
- Public Charging Rate accepts values in $/kWh.
- Public Session Fee accepts values in $.
- Charging Loss accepts values in %.
- Home Charging Cost is displayed as currency.
- Public Charging Cost is displayed as currency.
- Cost Difference is displayed as currency.
- Effective Public Rate is displayed as currency.
Rounding rules
- Number displays use up to 2 decimal places in the calculator UI.
- Currency outputs are displayed with standard US dollar formatting.
- Input precision follows configured step values where provided.
Version history
1.0.0 - 2026-05-06
Generated accuracy and testing page from the current home-vs-public-ev-charging-cost-calculator calculator definition.
Change log
2026-05-06
Published default regression test documentation and metadata fallbacks for Home vs Public EV Charging Cost Calculator.
Calculator transparency
Accuracy pages are generated from checked-in calculator definitions and can be upgraded with curated review metadata over time.