Extending battery life on the OSBee will require powering off the radio and putting the AVR into a sleep mode most of the time.
On a project I built a few years ago, I had the mains-powered host send a heartbeat every two seconds. The battery powered AVR remote device had a 32khz crystal for a RTC function. The first time the remote device read the heartbeat through the radio, it would zero it’s internal counter/timer to only wake up, power up the radio, and listen for commands during a 10 mS window every two seconds. This control scheme made a huge difference in battery life.