Power banks are portable chargers that allow you to recharge your electronic devices on the go. These devices store energy in internal batteries, which can then be used to charge a variety of devices such as smartphones, tablets, and other portable electronics. Power banks come in different shapes, sizes, and capacities, and offer a convenient and reliable source of backup power when you're away from a power outlet.

Power banks typically use lithium-ion or lithium-polymer batteries and feature one or more USB ports for charging. They can be charged through a USB cable connected to a wall adapter or through a solar panel if they have this feature. Some high-capacity power banks may also feature AC outlets for charging larger devices like laptops.

Power banks can be especially useful for outdoor enthusiasts, travelers, and anyone who relies heavily on their electronic devices throughout the day. With a power bank, you can ensure that your devices stay charged and ready to use at all times, without having to worry about finding a power outlet.