Lithium-Titanium-Oxide (LTO) is an ideal “zero-strain” battery anode with minimal volume change (<0.3%) during lithium insertion. Its high operating potential (~1.55V vs Li/Li+) suppresses electrolyte decomposition, solid electrolyte interface (SEI) formation, and dendrite growth, ensuring exceptional cycle life. However, this longevity creates a research paradox. Traditional accelerated aging tests (using extreme temperatures or high rates) alter the dominant degradation mechanisms, making it difficult to establish a unified understanding of LTO aging. To address this, researchers utilize the "float test" for continuous aging monitoring. By holding the battery at a constant voltage and recording the required maintenance current, this method isolates aging into two distinct processes: anode-related SEI formation and cathode-related lithiation. Using a specific scaling factor, the float current—driven by voltage decay—can accurately calculate the actual aging rates on both electrodes once the initial overhang effect is overcome. In a study of eight commercial LTO cells (with Lithium Cobalt Oxide cathodes) aged at 30 °C, researchers combined float analysis with Differential Voltage Analysis (DVA). By matching modified half-cell potential curves to measured full-cell curves, they successfully quantified the intensity of specific aging processes. Crucially, they distinguished between Loss of Active Material (LAM) and Loss of Lithium Inventory (LLI). They discovered that LLI at a low State of Charge (SOC) is directly linked to cathode LAM. By mathematically eliminating this LAM-induced LLI, researchers accurately isolated and estimated the pure cathode lithiation and SEI formation currents.