Bluetooth actions in general are heavy on phone's battery, and their operation sometimes needs to be customized to allow for best user experience. Quality of Service (QoS) is an AbleManager parameter that allows you to fine-tune how do certain parts of it work, like scanners and background services. You can instantiate your own QualityOfService class instance, or use one of the three pre-made QoSs.
QualityOfService.LOW_ENERGY offers shortest and farthest spaced scans with least reliability, but is best at conserving battery life.QualityOfService.DEFAULT represents a nice balance between battery conservation and effectiveness of bluetooth actions.QualityOfService.INTENSIVE scans often and is very efficient, but can be draining on the battery.