Had this same garbage can for very long time(years) before it died on me. Only had to change the batteries once in the entire time I had it.  We got so used to waving your hand over the can and having it open that anything less would be unacceptable.  Ordered this set from Wayfair and after installing the 3 battereis as opposed to the 4 in the previous model it is working like a charm.  Ordered from wayfair as I like the free delivery,and their customer service is always outstanding and on this item the price was the best.