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Home EV Charger Battery Degradation Calculator

This calculator estimates battery capacity loss associated with repeated home charging. It combines annual charging energy, the share charged at higher power, average state of charge, and years of use into a transparent planning estimate rather than a laboratory prediction.

Homeowners can use the result to compare gentler charging habits with more aggressive routines, estimate remaining usable capacity, and understand how charging behavior may contribute to long-term range loss. Actual degradation also depends on battery chemistry, temperature, vehicle age, driving load, and the vehicle's battery-management system.

Calculator inputs

kWh
kWh
years
%
%
Result
—
Estimated degradation
Estimated capacity loss—
Estimated remaining capacity—
Estimated range loss—

1. Enter battery capacity
Use the vehicle battery’s usable capacity in kilowatt-hours.

2. Add annual charging energy
Enter the approximate energy delivered at home in one year.

3. Set the time horizon
Choose how many years of charging to model.

4. Describe charging intensity
Enter the share of charging done at relatively high home-charging power.

5. Enter the usual charge target
Use the state-of-charge level you normally stop at.

6. Review the estimate
Compare percentage loss, lost kilowatt-hours, and remaining capacity.

Estimated degradation (%) = Years × Annual cycle equivalents × Base wear rate × Power factor × State-of-charge factor

Annual cycle equivalents = Annual charging energy ÷ Battery capacity
Base wear rate = 0.02% per equivalent full cycle for this planning model
Power factor = 1 + 0.30 × High-power share
State-of-charge factor = 1 + max(0, Charge target − 80%) × 0.015

What the result means

The main result is the modeled percentage of usable battery capacity lost over the selected period.

This is a comparative estimate, not a vehicle-specific warranty or health diagnosis. Calendar aging and temperature are not modeled separately.

Given: 75 kWh battery, 4,500 kWh per year, 5 years, 10% high-power share, and an 80% charge target.

Calculation: Annual cycle equivalents = 4,500 ÷ 75 = 60. Base loss = 5 × 60 × 0.02% = 6.00%. Power factor = 1 + 0.30 × 0.10 = 1.03. State-of-charge factor = 1.00. Estimated loss = 6.00% × 1.03 = 6.18%.

Result: Estimated remaining capacity = 75 × (1 − 0.0618) = 70.37 kWh.

The estimate suggests about 4.64 kWh of capacity loss under the selected assumptions.

Does home charging always damage an EV battery?

No. Normal home charging is generally managed by the vehicle, but cumulative energy throughput, heat, and prolonged high state of charge can contribute to aging.

What counts as high-power home charging?

Use the field as a relative share of charging performed near the upper power level supported by your home setup and vehicle. It is not intended to define one universal kilowatt threshold.

Why is the charge target included?

Keeping a battery near a very high state of charge for long periods can increase stress for many lithium-ion chemistries. The model applies an added factor only above 80%.

Can I use total electricity from my utility bill?

Use only electricity delivered to the vehicle, not whole-home consumption. Charger losses may be included if your source reports wall-to-vehicle energy.

How should I interpret the result?

Treat it as a scenario comparison. A lower estimate does not guarantee a particular battery-health reading, and a higher estimate does not prove a defect.