Significant temperature gradients are prone to occur inside large-capacity lithium iron phosphate (LiFePO4) batteries. Accurately mastering their thermal distribution characteristics is central to preventing thermal runaway triggered by local overheating and optimizing thermal management strategies, which is directly linked to system safety and battery longevity. In this paper, we systematically investigated the thermal distribution behaviors of 280 Ah LiFePO₄ batteries under different operation mode and temperature range. Charging and discharging experiment were carried out at 25 °C and 45 °C with 0.5C (constant-current (CC) mode) and 0.5P (constant-power (CP) mode) to study the difference of thermal distribution between different operation mode. In addition to tests at 25 °Cand 45 °C, we also conducted discharge tests under various P-rates at 0 °C and − 10 °C to study the battery’s thermal distribution characteristics at low temperatures. The temperature distribution during test were mapped and analyzed by the surface mounted temperature sensors. Our results show that for large-capacity energy storage batteries, significant differences exist in charge/discharge temperature rise between CC and CP modes, and notable disparities in temperature distribution emerge at low temperatures compared to room-temperature conditions. These findings can provide fundamental insights for thermal management design in grid-scale energy storage systems, proposing sensor placement optimization strategies.