When sourcing solar searchlights, you must prioritize Luminous Efficacy (Lumens per Watt) and Battery Capacity. Look for units offering at least 150lm/W to ensure high brightness with lower energy consumption. The battery should be LiFePO4 (Lithium Iron Phosphate), as it offers over 2,000 charge cycles and better thermal stability compared to standard Li-ion batteries. Additionally, ensure the Solar Panel Type is Monocrystalline Silicon, which provides a higher conversion efficiency (up to 22%) than polycrystalline alternatives, especially in low-light conditions.