How long do the batteries last in a motion-sensor trash can?

Reports vary widely. A high-trust r/smarthome commenter reported changing AA batteries only once in 10 months, and EKO and iTouchless both advertise roughly six-month performance. But r/BuyItForLife threads complain that some sensors 'waste a ton of batteries.' Many models, including the iTouchless cans here, accept an AC adapter to sidestep batteries entirely.