When sourcing LiFePO4 (Lithium Iron Phosphate) batteries, you must prioritize Cycle Life, which should typically exceed 3,500 to 6,000 cycles at 80% Depth of Discharge (DOD). Verify the Grade of the cells (Grade A is essential for longevity) and ensure the Battery Management System (BMS) includes protections against overcharge, over-discharge, short circuits, and thermal runaway. Additionally, check the Energy Density (Wh/kg) and Discharge Rate (C-rating) to ensure they meet your specific application needs, whether for solar storage or EV use.