You could recharge the portable charger with a power source such as a USB wall charger. Charging a portable power bank is typically a simple process. Here are the general steps you can follow:

1. Check the power bank's capacity: Most power banks have a capacity rating in mAh (milliampere-hours), which indicates how much energy they can store. Check the capacity of your power bank to know how many times you can recharge your device with it.

2. Use the correct cable: Most power banks have a charging cable included when purchased. If your power bank doesn't come with a cable, you will likely use the same cable you use to charge your device.

3. Connect the cable to the power bank: Insert one end of the cable into the power bank's input port. The input port is usually labeled "input" or "in" and may be a micro-USB, USB-C, or Lightning port, depending on the power bank.

4. Connect the cable to a power source: Plug the other end of the cable into a USB wall charger or a USB port on a computer. Make sure that the power source can supply the necessary amperage and voltage to the power bank.

5. Start charging: Once the power bank is connected to the power source, it should start charging automatically. Most power banks have LED lights or a display indicating charging status. The lights may blink or turn off when the power bank is fully charged.

6. Disconnect and use: When the power bank is fully charged, disconnect it from the power source and use it to charge your device. Some power banks have multiple output ports to charge multiple devices simultaneously.

It's important to note that the charging time may vary depending on the capacity of the power bank, the capacity of the device being charged, and the amperage and voltage of the power source. Be sure to use the right cable and power source to ensure safe and efficient charging.

UGREEN power banks are portable devices that store electrical energy, so you can charge your smartphones, tablets, and other electronic devices on the go. They typically feature multiple USB ports, allowing you to charge several devices at the same time. UGREEN offers a variety of power banks with different capacities and designs to meet your specific needs, ensuring your devices stay powered up when you're away from an outlet.

If you're looking for a lightweight and portable power bank with fast charging capabilities, the UGREEN Nexode Power Bank 20000mAh 130W Fast Charging Power Bank is an excellent choice. With its 100W output, it can quickly charge multiple devices. It also features a smart TFT display that clearly shows the remaining battery life and other useful information. Frequent travelers will appreciate that it’s airline-approved, making it convenient for air travel.

For those who need to charge a laptop, we recommend the UGREEN 145W 25000mAh Laptop Power Bank. This power bank boasts a larger capacity and higher power output to keep your laptop running. It supports the PD3.1 fast charging protocol, which enables faster charging of compatible devices. Plus, it has three ports for charging multiple devices simultaneously.

If you require a power bank with massive capacity and ultra-high power output, the UGREEN 300W 48000mAh High-Capacity Power Bank is the perfect solution. With a whopping 48000mAh capacity and 300W output, it can provide extended power to all your devices. It even includes a built-in LED flashlight for emergencies.

The capacity of your portable power bank depends on the devices you need to charge and their battery sizes. If you're charging just a smartphone, a power bank with 5000mAh to 10000mAh should suffice. However, if you're charging multiple devices or larger ones like tablets or laptops, you might need a power bank with 20000mAh or more.

Keep in mind that nominal capacity differs from actual usable capacity due to conversion efficiency. And for charging laptops, output power (30W, 65W, 100W) is more important than capacity—not every 20000mAh power bank can charge a laptop.