Speaker on Sector
Moving your speaker is not an obligation, because you are mainly looking to listen to your music in a room: living room, bedroom, ... Opt for a mains speaker!
If you do not move your speaker regularly, the battery will be rather a constraint.
You want to listen to your music in your living room, if you opt for a battery-powered speaker you will have to think about recharging it. If you leave the speaker plugged continuously into the mains, you will damage its battery.
Let's summarize: if you want to listen to your music in a particular room, opt for an AC speaker, without charging constraints and for a more powerful sound.