We tested Bluetooth speakers with expert listeners, and we concealed the identities with the speakers to eliminate bias. For all 25 speakers we tested, the average battery life was a little under 17 hrs. The Sony Ult Area seven wins the title for best battery life (thirty hrs). At https://www.bluetoothspeaker.top/waterproof-bluetooth-speaker-handsfree-noise-reduction-dustproof-bluetooth-speakers/