claims state the rechargeable/secondary batteries will last up to 40 years and that it is highly unusual for these batteries to fail. These rechargeable/secondary batteries last significantly longer than a typical quartz-watch battery, but when stored, attention must be given to keep the rechargeable/secondary batteries in Eco-Drive watches sufficiently energized to ensure a long-lasting correctly functioning movement. Maintenance For water resistant and diving Eco-Drive watches Citizen recommends a watch gasket exchange every 2 or 3 years to preserve their water resistance because watch gaskets, which form a watertight seal, degrade as they age. Further, Citizen recommends maintenance for Eco-Drive watch movements in regular intervals in order to extend the life of the watch movement, since the gears used in running watch movements are subject to slow wear. Citizen states that when their lubricants for Long-Lasting Precision Equipment are used in watches, timepiece movements remain smooth for a long time as the oil does not harden even after 20 years. Gallery See also Watch Solar powered watch References External links Citizen Holdings Co., Ltd. Solar-powered devices Watches