How do you charge the battery of a rechargeable flashlight?

The green light means it is charging, and the red light means it is fully charged.
Rechargeable flashlights are designed for energy conservation and environmental protection, and are also a way for businesses to adapt to consumer needs and reflect social responsibility. The emergence of rechargeable flashlights solves the trouble of replacing batteries and is also beneficial for protecting environmental resources. Rechargeable flashlights usually use LED bulbs, which have a long lifespan. The light of the flashlight is close to that of sunlight, which is bright and clear, and is conducive to distinguishing the true color of objects.