How does cold temperature affect lithium polymer (LiPo) battery performance in a small UAS?

Why →LiPo batteries rely on electrochemical reactions that are temperature-dependent. Cold slows those reactions, increases internal resistance, and reduces both capacity and voltage output. A battery providing 20 minutes of flight at 70°F may deliver only 12–15 minutes at 35°F. Cold takeoffs demand higher current during the initial flight phase.

The trap →The "cold improves electronics" intuition comes from semiconductor cooling, not electrochemistry. For batteries the effect runs the other way, and it is not small.

Field note →Keep batteries at room temperature before flight using an insulated pouch, and plan for 20–35% shorter flight times below 40°F. Never charge a cold LiPo below 32°F. It can cause lithium plating that permanently damages the cell and creates a fire hazard.