[Safety Assurance]: 𝟣𝟪𝟨𝟧𝟢 Battery Charger 4 Slot Discharge Function Comes with special charge and discharge management circuit. With multiple security protection settings, the 𝟣𝟪𝟨𝟧𝟢 4 Bay charger can effectively prevent reverse, short circuit, overcharge, over discharge, over-current damage to the Li-ion battery, which makes users using the product without any safety concern. Red light when charging, green light when fully charged.