A:
The Bose Soundlink Mini has a lithium Ion battery. Lithium Ion batteries have been shown to lose capacity if constantly charged. On the flipside, completely discharging them for an extended period of time will also diminish their capacity. They are much more durable to the older NiMH and NiCd batteries as they do not suffer from "memory effect".
The Bose Soundlink Mini has a multi-colored power indicator. Flashing yellow means charging. Green is a charge of 70%-100%. Solid yellow is 20%-70%. Red indicates 20% or below. Ideally you will want to keep the charge between 20%-100%. I would recommend charging it full then using it wireless. Once it hits yellow, use it for a few more hours wireless while still yellow then charge it fully. This should maximize battery life.
Luckily for you. Bose made this speaker with a replaceable battery while virtually all other Bluetooth speakers have an un-serviceable battery.