For proper maintenance of a lithium-based battery, it’s important to keep the electrons in it moving occasionally. Apple does not recommend leaving your portable plugged in all the time. An ideal use would be a commuter who uses her MacBook Pro on the train, then plugs it in at the office to charge. This keeps the battery juices flowing. If on the other hand, you use a desktop computer at work, and save a notebook for infrequent travel, Apple recommends charging and discharging its battery at least once per month."
I was sufficiently pleased by the FRITZ!Box that I bought a 2nd one to extend the wifi in my home - very easy to do with the fritz devices.
[1] https://www.zen.co.uk/broadband/broadband-router