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Fleet EV Charger Battery Degradation Calculator

This calculator estimates the battery-capacity loss associated with operating an EV fleet and its charging schedule. It combines energy throughput, an assumed degradation rate per equivalent full cycle, calendar aging, and an optional high-state-of-charge adjustment to produce a planning estimate for remaining usable capacity.

Fleet managers can use the result to compare charging strategies, approximate when battery health may affect route coverage, and test how annual mileage or charging behavior changes long-term capacity. The model is deliberately assumption-driven: actual degradation depends on battery chemistry, thermal management, climate, charging power, storage state of charge, and vehicle-specific controls.

Enter assumptions

vehicles
kWh
kWh
years
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Result
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Estimated result
Estimated remaining capacity—
Equivalent full cycles / vehicle—
Fleet usable capacity lost—
Average annual capacity loss—

1. Enter fleet and battery size

Use the number of vehicles and nominal battery capacity for one vehicle.

2. Add annual energy throughput

Enter charging energy delivered to each vehicle over a typical year.

3. Set the planning period

Choose the number of years covered by the estimate.

4. Define degradation assumptions

Enter cycle-related loss, calendar aging, and the optional high-state-of-charge penalty.

5. Review capacity impact

Use total loss, remaining capacity, equivalent cycles, and fleet-wide lost capacity for planning.

Equivalent full cycles = (Annual energy × Years) ÷ Battery capacity Cycle loss (%) = Equivalent full cycles ÷ 1,000 × Cycle fade rate Calendar loss (%) = Years × Calendar fade rate High-SOC loss (%) = Years × High-SOC penalty × High-SOC share Total loss (%) = Cycle loss + Calendar loss + High-SOC loss

Energy is entered per vehicle. The model treats one equivalent full cycle as cumulative energy throughput equal to the battery's nominal capacity. The three loss components are added and capped at 100%.

What the result means

A higher percentage means less usable battery capacity remains for the same fleet routes and charging windows.

This is a scenario estimate, not a battery-health diagnostic. Use vehicle telematics or manufacturer service data for asset-level decisions.

Given: 40 vehicles, 82 kWh each, 16,500 kWh per vehicle per year, 5 years, 6% loss per 1,000 cycles, 1.2% calendar loss per year, 20% high-SOC exposure, and a 0.8% annual high-SOC penalty.

Calculation: Equivalent cycles = (16,500 × 5) ÷ 82 = 1,006.1. Cycle loss = 1,006.1 ÷ 1,000 × 6% = 6.04%. Calendar loss = 5 × 1.2% = 6.00%. High-SOC loss = 5 × 0.8% × 20% = 0.80%. Total loss = 12.84%.

Result: Estimated remaining capacity is 87.16%, and fleet-wide usable capacity loss is about 421.2 kWh.

What is an equivalent full cycle?

It is cumulative battery throughput equal to one full nominal battery capacity. Two 50% discharges count as roughly one equivalent full cycle.

Should charger losses be included in annual energy?

Use energy that reaches the vehicle battery when available. If your meter measures grid energy, reduce it to reflect charging losses before entering it.

Does fast charging always cause the entered cycle fade?

No. The cycle fade rate is an assumption that should reflect the fleet, battery chemistry, temperature controls, and charging pattern.

Why is the estimate capped at 100% loss?

Capacity loss cannot exceed the starting nominal capacity. Long scenarios that reach the cap are outside the practical range of this simple model.

How should this result be used in replacement planning?

Treat it as a scenario comparison. Combine it with warranty thresholds, route energy needs, measured state of health, and maintenance records.