Hello, - yes, I have already found such solutions for other models, but I don't think everyone is up to the task of doing it themselves, so in my opinion two points are important:
1. Appropriate support from the dealer when replacing the battery.
2. As with the FiiO, I have the M11 Plus myself, an appropriate battery management system with which you can limit the charge to 80%. This saves the battery a bit, especially if you operate the devices on the mains. The new M23 even goes a step further here, it has two USB ports, one is only for data exchange and the other is solely responsible for the power supply, so you can completely decouple the battery from the system when you don't need it.
(Sorry if the grammar is a bit incorrect, I have my texts translated by Google, unfortunately my English is not that good)
1. Appropriate support from the dealer when replacing the battery.
2. As with the FiiO, I have the M11 Plus myself, an appropriate battery management system with which you can limit the charge to 80%. This saves the battery a bit, especially if you operate the devices on the mains. The new M23 even goes a step further here, it has two USB ports, one is only for data exchange and the other is solely responsible for the power supply, so you can completely decouple the battery from the system when you don't need it.
(Sorry if the grammar is a bit incorrect, I have my texts translated by Google, unfortunately my English is not that good)