The State of Health (SoH) describes the current condition of a battery relative to its as-new state. An SoH of 100% corresponds to a new battery; 80% is typically considered end-of-life for first-life applications.
SoH is defined via two parameters: Capacity SoH (remaining capacity vs. nominal capacity) and Resistance SoH (DC internal resistance vs. as-new value). PV-BESS-Assessor conducts independent capacity tests and EIS measurements (Electrochemical Impedance Spectroscopy) for SoH determination.
SoH determines the economic residual value of a battery storage system. In transactions, insurance claims, and warranty disputes, an independent SoH assessment by qualified experts is indispensable. The discrepancy between manufacturer-reported SoH and independently measured SoH can be significant.
Typically, an SoH of 80% is considered end-of-life for first-life applications. The battery can subsequently be reused in second-life applications with lower performance requirements. The actual usability depends on the application profile.
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Last updated: 2026-06-16