Battery Degradation Calculator

Battery Degradation Calculator Estimates the battery's State of Health (SoH) based on capacity, charge cycles, depth of discharge, and age.

  • Wh
  • kWh
  • Years
  • Months

About the Battery Degradation Calculator

The Battery Degradation Calculator is a tool designed to help you estimate the current State of Health (SoH) of your lithium-ion battery pack.

By providing information about your battery's capacity, charge cycles, depth of discharge, and age, you can get a rough idea of how much your battery has degraded over time.

How to Use the Calculator

  1. Enter your battery's original capacity in Watt-hours (Wh) or Kilowatt-hours (kWh). This is optional but will provide an estimate of the hypothetical maximum capacity based on the calculated SoH.
  2. Input the number of charge-discharge cycles your battery has undergone. This is optional if you specify the battery age.
  3. If you entered the charge cycles, you can also provide the average depth of discharge (DoD) your battery experiences during its cycles. This is expressed as a percentage from 0-100. If left blank, a standard value of 70% is assumed.
  4. Enter the age of your battery in years or months. This is optional if you specified the charge cycles.
  5. The calculator will display the estimated State of Health (SoH) as a percentage and, if capacity was provided, the hypothetical maximum capacity in Wh.

Key Terms

  • State of Health (SoH): A measure of a battery's current condition compared to its original condition when new.
  • Capacity: The amount of energy a battery can store, typically measured in Watt-hours (Wh) or Kilowatt-hours (kWh).
  • Charge Cycles: The number of times a battery has been charged and discharged. One cycle is typically counted when the total discharge equals the battery's capacity.
  • Depth of Discharge (DoD): The percentage of a battery's capacity that is discharged during a cycle.

Calculation Formulas and Logic

The calculator uses simplified formulas to estimate battery degradation based on charge cycles and age. These formulas are:

Cycles Degradation

Cycles Degradation = Charge Cycles × Depth of Discharge 100 × 0.06

Age Degradation (in months):

Age Degradation = Battery Age × 0.3

The calculated degradation values are subtracted from an initial SoH of 100%, and the result is clamped between 0% and 100%.

If the original capacity is provided, the hypothetical maximum capacity is calculated by multiplying the original capacity by the estimated SoH percentage.

SoH = 100 - Cycles Degradation - Age Degradation

Disclaimer and Limitations

This calculator provides a rough estimate based on simplified formulas and assumptions. The actual degradation of a battery depends on various factors such as battery chemistry, manufacturing quality, operating conditions, and temperature.

The results should be used as a general guide, not as a precise measurement of your battery's health.

The calculator's estimates are designed primarily to match lithium-ion batteries in electric vehicles. A more accurate assessment should be performed for critical applications or specialized battery systems.

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