I own two of these units, one for house and other on garage. House unit is used half as much as garage unit, and both units have held up well in over three years of use. Garage batteries will last about 6months(4 AA's) and house bout a year. We also oil/lubricate deadbolt pin bout twice a year, to reduce wear from moisture/rust. These are the first time we have owned them and are impressed by ease of use and ability to change code quickly. Also had to contact kwikset customer service and they were excellent with my inquiry, unlike most companies you deal with today. Would recommend these to anyone needin good security and ease of use.