This estimator projects how much usable battery capacity a fleet may retain after a chosen number of years. It combines annual mileage, vehicle efficiency, battery size, cycling-related degradation, and calendar aging into a simple planning estimate. Fleet operators can use it to compare replacement timing, warranty assumptions, route suitability, and expected range over the service life.
Battery aging depends on chemistry, temperature, charging habits, depth of discharge, and many other factors. The result is therefore a scenario estimate rather than a prediction for a specific pack.
1. Enter original capacity
Use the usable battery capacity when the vehicle was new.
2. Add annual duty
Enter expected annual mileage and the vehicle’s average miles per kilowatt-hour.
3. Set cycling degradation
Enter the assumed percentage-point loss for each equivalent full cycle.
4. Include calendar aging
Add the estimated annual capacity loss that occurs with time.
5. Choose service life
Enter the number of years to project and review retained capacity and equivalent cycles.
Energy throughput = Annual miles × Years ÷ Efficiency
Equivalent cycles = Energy throughput ÷ Battery capacity
Total degradation (%) = Cycles × Loss per cycle + Years × Calendar loss
Retained capacity = Original capacity × (1 − Total degradation ÷ 100)
This additive model is deliberately simple. Actual degradation is often nonlinear, and the assumed cycling and calendar rates should be adjusted to match vehicle data or a manufacturer-supported model.
The primary result is estimated capacity retention based on the values entered above.
Use the result as a scenario estimate. Validate material assumptions with operational data, technical documentation, or qualified advisers as appropriate.
Given:
80 kWh battery, 30,000 miles per year, 2.8 mi/kWh, 0.025% loss per equivalent cycle, 1.5% calendar loss per year, and 6 years.
Calculation:
Throughput = 30,000 × 6 ÷ 2.8 = 64,285.7 kWh. Equivalent cycles = 64,285.7 ÷ 80 = 803.6. Cycling loss = 803.6 × 0.025% = 20.1%. Calendar loss = 6 × 1.5% = 9.0%. Total loss = 29.1%.
Result:
Capacity retention = 70.9%, or about 56.7 kWh remaining.
Interpretation:
The vehicle may need route reassessment before year six if its duty cycle depends on most of the original range.
It is cumulative energy throughput equal to one full battery capacity. Two 50% discharges count as roughly one equivalent full cycle.
Yes, but efficiency must use kilometers per kilowatt-hour so the distance units cancel correctly.
The calculator uses an accessible planning model. More advanced models may combine aging mechanisms nonlinearly and include temperature and state-of-charge history.
The displayed degradation is capped at 100%. In practice, a battery would be retired or repurposed well before reaching that theoretical point.
No. Warranty tests, thresholds, exclusions, and measurement methods are manufacturer-specific.