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

Battery Degradation 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

Future capacity = original capacity x (1 - current degradation) x (1 - annual degradation) ^ years.

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
Original Battery Capacity: 75 kWh
Original Rated Range: 330 mi
Current Degradation: 8%
Future Annual Degradation: 1.5 %/yr
Years Ahead: 5 years

Expected outputs

Future Battery Capacity: 63.98 kWh
Current Capacity: 69 kWh
Future Rated-Equivalent Range: 243.12 mi
Total Degradation: 14.70%

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, fees, rates, and vehicle assumptions are user-entered.
Calculations run locally in your browser and are not stored by Calwarden.
This is planning math, not financial, tax, insurance, legal, or mechanical advice.

Unit handling

EV Model Preset accepts one of the configured options.
Original Battery Capacity accepts values in kWh.
Original Rated Range accepts values in mi.
Current Degradation accepts values in %.
Future Annual Degradation accepts values in %/yr.
Years Ahead accepts values in years.
Future Battery Capacity is displayed in kWh.
Current Capacity is displayed in kWh.
Future Rated-Equivalent Range is displayed in mi.
Total Degradation is displayed as a percentage.

Rounding rules

Number displays use up to 2 decimal places in the calculator UI.
Percent outputs are displayed with two decimal places.
Input precision follows configured step values where provided.

Version history

1.0.0 - 2026-05-06

Generated accuracy and testing page from the current battery-degradation-calculator calculator definition.

Change log

2026-05-06

Published default regression test documentation and metadata fallbacks for Battery Degradation 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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