Like the 1st-gen model, the battery is replaceable and can be accessed by way of hidden screws on the bottom on the speaker. You will find an application You should use with the SoundLink Max, but it is not obligatory. If you are doing utilize it, you will get https://www.bluetoothspeaker.top/new-arrival-speakers-outdoor-waterproof-portable-subwoofer-wireless-bt-5-0-speaker-with-bass/