1. Buy a 13.8V power supply for Huawei, HP, or Dell servers that has been converted from an existing one; prices range from 45 to 80 yuan per month on Xianyu.
2. Purchase a dedicated power supply like "Qujing," which are available in various models and price ranges (hundreds to thousands of yuan), depending on your needs and budget.
3. Purchase a professional repair power supply that allows you to adjust the voltage; this option offers the highest practicality, but it is also the most expensive.
4. Buy a power bank, such as those sold by Dian Shi Er or on JD.com. These power banks have cigarette lighter sockets, which can be used to plug in the car's cigarette lighter socket. I use this method.
5. Buy a used 12V battery and a standard 12V charger, and connect the radio to the battery for use. Recharge it with the charger when the battery is depleted. That's exactly how I do it.
Ideally, it's best to buy a variable power supply; secondly, consider modifying an existing server with a power supply. This will allow you to use higher-power devices (hundreds of watts) in the future.
I chose between two options, as they were readily available and didn't require purchasing anything.