This was a great automatic feeder for controlling my cat's weight and not sure what I would do without it.  We only used it for dry food (did not feed our cat wet food) so we never used the cold packs.  We put it on every 6 hours (lasted 1.5 days) and filled it once a day.  When we first received it, we were disappointed since you could hear it when it was spinning (and it was right outside our bedroom), however we got used to it and our cat was trained to know the feeding time from the noise.  I felt the battery lasted a good amount of time.  The only difficulty is the feeder has 6 slots so if you put it on every 6 hrs feeding, it would run out after 1.5 days.  Can put it on 12 hrs and it will last longer.