Heat is the enemy when you charge. Charge at room temperature — never in direct sun, a heat-soaked garage, or a hot shed. Extreme heat stresses the battery and raises the risk of it failing while it's plugged in. Cool shade, room temp, every time. Grounded in Fire Prevention Week 2026 'Charge into Fire Safety' guidance: store and charge batteries at room temperature, away from extreme heat, cold, and direct sun.