Battery Case for iPhone 11 Pro, 4800mAh Portable Protective Charging Case Extended Rechargeable Charger Case Smiphee (Black)

Capacity: Power banks come in various capacities, measured in milliampere-hours (mAh) or watt-hours (Wh). The higher the capacity, the more charge a power bank can provide to your devices., Output Power: The output power of a power bank is measured in volts (V) and amperes (A). Multiply these values to get the output power in watts (W). Devices usually require a specific voltage and amperage to charge optimally., USB Ports: Power banks typically have one or more USB ports for connecting charging cables. Some may also have USB-C or micro USB ports for recharging the power bank itself., Size and Weight: Power banks come in various sizes and weights. Smaller ones are more portable but may have lower capacities, while larger ones can provide more charge but may be heavier and less convenient to carry., Charging Speed: The charging speed of a power bank depends on its output current. Higher output currents generally result in faster charging, but it's essential to match the power bank's capabilities with your device's requirements.