I have purchased pure it water filter from you, and after 6 months i saw the battery indicator showing red mark, as it was told that one battery kit filters 1500 liters of water, but when i changed the battery first time after that the kit only worked for 2 months, approximately it must have filtered not more than 150 liters of water. Because during first six months the use was excessive because of guests in my house, even though the battery...