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EV Battery State of Charge (SoC) Calculator

Estimated state of charge

Enter pack voltage and empty/full endpoints

How this calculator works

How to use the EV Battery State of Charge (SoC) Calculator

The Formula

Resting pack voltage maps to state of charge through the pack OCV curve. This tool uses a linear interpolation between your empty and full voltage endpoints—a planning baseline before applying chemistry-specific lookup tables.

Practical Example

The vehicle BMS blends coulomb counting, temperature compensation, and cell balancing. Voltage alone under load is not reliable—always measure at rest for field checks.

About EV Battery State of Charge (SoC) Calculator

Voltage-based SoC estimation

Resting pack voltage maps to state of charge through the pack OCV curve. This tool uses a linear interpolation between your empty and full voltage endpoints—a planning baseline before applying chemistry-specific lookup tables.

When readings differ from the dash

The vehicle BMS blends coulomb counting, temperature compensation, and cell balancing. Voltage alone under load is not reliable—always measure at rest for field checks.