How deep is the second-hand mobile phone water on Taobao, Zhihu?

Taobao's second-hand mobile phones are good and bad, but as far as I know, most of them feel good after buying them, but after using them for a long time, many problems will be gradually discovered. To sum up, the common problem is not the function, but the poor cooperation with the battery, that is, the battery is very good and full of electricity, but it will heat up if it is not used for a long time, or the mobile phone is not used for a long time. But personally, I think second-hand is still a good choice for some people. Cheap and fashionable, it's ok to take it out, haha. If you don't use it for a long time, I suggest you buy it second-hand. I hope I can help you. You'd better give me a good review, hehe.