1. There is no need to buy a battery pen. 2. The reason is that the pen of iPad usually uses wireless charging technology, which can be charged by magnetic absorption or inserting into the charging port of iPad, without the need to purchase additional batteries. 3. The advantages of this design are convenient and fast, and there is no need to replace the battery frequently, saving the use cost and environmental resources. In addition, wireless charging technology also improves the user experience, making it more convenient for users to create and operate.