I have two MegaBoom 2’s—one is a complete champ, the other has very short battery life at this point.
They both work for my needs—the short battery one is in my bathroom and I leave it plugged in now.
The other one just floats around the house and gets a decent amount of use from my kids, who may or may not be slightly older than the speakers themselves.
The fact that they both work and only one has noticeably degraded battery life is surprising.